Orton Sentry 2.0 User manual

1
See pages 24 - 25 for instructions on upgrading your DTC
100, 600, 800 or 1000 series board to the Sentry.
Program Review (pg 9)
From IdLE or during
firing, press 6.
Shows the program that is
loaded in memory and ready to
fire, or the one that is firing.
Skip Segment (pg 13)
During firing, press 9, then
Enter.
Skips to the next ramp.
Stop/Back (pg 7)
Press during firing or
programming.
Stops a firing.
In Options, takes you back
to .
During programming, takes
you back one step each
time key is pressed.
Options (pg 14-18)
From IdLE, press 0. Press
Enter for option displayed.
Change the thermocouple
temperature. (Pg 14)
(Pg 15)
Se-
lect Type K, S or R. (Pg 15)
Select vent
fanoralarm.Thisisaspecialop-
tion not on all kilns. (Pg 16)
Shows the factory setting. (Pg 16)
Enter the
rate shown on your electric bill.
(Pg 16)
Enter your kiln’s wattage. (Pg 16)
Alarm (pg 12)
From IdLE or during
firing, press 7.
Enter a temperature. When
alarm sounds during firing,
press Enter.
Present Status (pg 12)
During firing, press 5.
Shows the segment number that
is currently firing and whether the
segment is in ramp or hold.
Add Time (pg 11)
During firing, press 2.
Each additional key press
adds five minutes to a hold.
Enter/Start (pg 8)
Press Enter/Start after each
step in programming a firing.
Press Enter/Start once from
to begin firing.
Select
identification number for output to
a computer. (Pg 17)
Set temperature sensitivity for
FTH, FTC & LTdE error codes.
(Pg 17)
(Pg 17)
Check for overheating. (Pg 18)
Make a
program tamper-proof. (Pg 18)
For
technicians. (Pg 18)
(Pg 18)
Diagnos-
tics tool. (Pg 18)
Removes thermo-
couple offset and returns the
board to factory defaults. (Pg 18)
Multiple-Zone Options
(pg 14)
Largest
temperature difference be-
tween any two zones. (Pg 14)
Shows temperature of each
zone. (Pg 14)
Complete Ramp-Hold Operating Instructions
IM-218/12-06
Firing Cost (pg 12)
Press 8 after the kiln
fires to completion.
The cost of the last firing
will appear. (First enter
electrical cost in the
option and kiln
wattage in the op-
tion, pg 16.)
Delay (pg 11)
From IdLE, press 3.
Enter time in hours:minutes.
Delays the start of firing.
Program (pg 8)
From IdLE, press 4.
Select stored program (1 - 4).
Enter rate, temperature, and
hold for each segment.
Edit a Program (pg 13)
During firing, press 4.
Change the current segment
temperature. Press Enter.
Change the hold. Press Enter.
The kiln will continue firing.
Sentry 2.0
Digital Temperature Controller

2Ramp-Hold
Introduction
Thank you for purchasing the Sentry micro processor, our most advanced generation of digi-
tal temperature controllers. As you read the manual, have your controller in front of you so
that you can try out the keys.
The controller display messages are limited to four characters. For this reason, the messages
appear cryptic: IdLE instead of “Ready to begin,” CPLT instead of “Fired successfully to
completion,” RA1 instead of “Enter rate for first segment.” If at any time you are confused by
these messages, turn to Appendix A: Display Messages on pages 22 - 23.
The front cover is a quick guided tour of the controller. The back cover is a quick guide to
programming, to be used after you have learned the programming in-
structions on page 8.
Do not worry if you hear a clicking noise during operation. Mechanical
relays click as they turn the heating elements on and off. This is normal.
ThewarrantyonyourSentrycontrollerdoesnotcoverdamagefrom
overfiring, regardless of the circumstances. It is the operator’s responsi-
bility to make sure the kiln turns off at the end of the firing.
If you purchased the TnF 2 portable controller, you should find a TnF 2
installation instruction sheet in addition to these instructions.
Instructions for multiple-zone kilns are included in this manual on pages 13 - 14. If you are
not sure whether your kiln is multiple-zone, look into the firing chamber. If you see two or
three thermocouple tips, your kiln is multiple-zone. If you see only one thermocouple, skip
multiple-zone instructions.
New features introduced with Sentry software version 18D: The Rate option (page 16), rate
shown in Present Status (page 12), firing cost calculation (page 16),
TCL alarm (page 21), PF1 alarm (page 20), and 2 segments added to
the User 1 program for a total of 20 (page 7). To check the software ver-
sion of your Sentry, press the OPTIONS key repeatedly until SOFT ap-
pears. Press ENTER. Your controller’s software version will appear.
18D and later versions include the new features.
Once you learn the basic features of the Sentry, you will be able to
control every stage of firing. This offers learning opportunities and
convenience difficult to imagine with a manual-controlled kiln.
©2001, by Paragon Industries, Inc. IM-218/1-07
Do not worry if
you hear a click-
ing noise during
operation. Me-
chanical relays
clickastheyturn
the heating ele-
ments on and off.
Do not leave the
kiln unattended,
especially near
the expected
shut-off time. Be
there to make
sure the kiln
turns off.

3
Contents
Getting Started. . . . . . . . 5
Room Temperature
and Humidity . . . . . . . . . . . . . . . . 5
Thunder Storms and
Power Surges . . . . . . . . . . . . . . . 5
Time and Temperature Display. . 5
The IdLE Display . . . . . . . . . . . . . 5
Thermocouple Inspection. . . . . . 5
Preventing an Overfire. . . . . . . . . 6
Theory of Operation . . . . . . . . . . 6
Programming
Instructions . . . . . . . . . . 7
The Stop/Back Key . . . . . . . . . . . 7
Correcting Entries . . . . . . . . . . . . 7
Canceling a New Program . . . . . 7
Storing “User” Programs . . . . . . 7
Firing a Stored User Program. . . 7
Rate . . . . . . . . . . . . . . . . . . . . . . . 7
Hold . . . . . . . . . . . . . . . . . . . . . . . 8
Programming Steps . . . . . . . . . . 8
Repeat Firings . . . . . . . . . . . . . . . 9
Program Review . . . . . . . . . . . . . 9
Programming a
Cooling Segment . . . . . . . . . . . . 9
CPLT Message . . . . . . . . . . . . . . 9
Temperature Overshoot . . . . . . 10
Starting a Firing in a Hot Kiln . . 10
AOP Fan . . . . . . . . . . . . . . . . . . 10
A Practice Program . . . . . . . . . . 10
Sample Firing
Programs . . . . . . . . . . . 10
Heat Treating D-2 Steel . . . . . 10
Glass Fusing Firing Schedule 10
Glass Slumping
Firing Schedule . . . . . . . . . . . 11
Other Features . . . . . . . 11
The Add Time Key. . . . . . . . . . . 11
Delay Fire . . . . . . . . . . . . . . . . . 11
Present Status . . . . . . . . . . . . . . 12
The Temperature Alarm . . . . . . 12
Estimating the Firing Cost. . . . . 12
Skip Segment . . . . . . . . . . . . . . 13
Editing the Current Segment
During Firing . . . . . . . . . . . . . . . 13
Multiple-Zone Kilns . . . 13
An Overview of Multiple-
Zone Firing . . . . . . . . . . . . . . . . 13
Thermocouple Failure
In a Multiple-Zone Kiln . . . . . . . 13
Power Output Lights . . . . . . . . . 13
Testing Multiple-Zone
Elements . . . . . . . . . . . . . . . . . . 14
DIFF / Zone Temperature
Difference . . . . . . . . . . . . . . . . 14
T123 / Zone Temperature
Display. . . . . . . . . . . . . . . . . . . . 14
The Options Key. . . . . . 14
TCOS / Thermocouple Offset . . 14
Calibrating Thermocouple
Offset With a
Digital Pyrometer . . . . . . . . . . 14
Setting Thermocouple Offset . 15
Multiple-Zone
Thermocouple Offset . . . . . . . 15
CHG- / Selecting °F or °C . . . . . 15
°F/°C Temperature
Conversion Formula. . . . . . . . 15
TC / Thermocouple Type . . . . . 15
AOP / Auxiliary Outlet . . . . . . . . 16
RATE / Types of Rates . . . . . . . 16
COST / Electric Cost
Per Kilowatt-Hour . . . . . . . . . . . 16
KW / Kilowatts Used to
Calculate Firing Cost. . . . . . . . . 16
Id / Computer ID . . . . . . . . . . . . 17
TEdE / Temperature Deviation . 17
SFTY / Maximum Temperature. 17
ELEC / Electronics
Temperature . . . . . . . . . . . . . . . 18
LOCK / Program Lock. . . . . . . . 18
CFG / Configuration Code . . . . 18
SOFT / Software Version. . . . . . 18
TEST / Element Test . . . . . . . . . 18
RST / Reset . . . . . . . . . . . . . . . . 18
Error Messages . . . . . . 19
FTC / Failed to Cool . . . . . . . . . 19
FTH / Failed to Heat . . . . . . . . . 19
LTdE / Low Temperature
Deviation . . . . . . . . . . . . . . . . . . 19
PF / Power Failure. . . . . . . . . . . 19
TC with Lines / Multiple-Zone
Kiln Thermocouple Failure . . . . 19
- - - - / No Thermocouple. . . . . . 20
BAdP / Bad Programming . . . . 20
ETH / Electronics Too Hot . . . . 20
FAIL / Thermocouple Failure . . 20
FTL / Firing Too Long . . . . . . . . 20
HTdE / High Temperature
Deviation . . . . . . . . . . . . . . . . . . 20
PF1 / Power Failure. . . . . . . . . . 20
PF 2 / Power Failure . . . . . . . . . 20
PF 3 / Power Failure . . . . . . . . . 20
TC 2 / Thermocouple Failure . . 20
TCL / Thermocouple Lag . . . . . 21
LId / Missing Connector Pin . . . 21
TCdE / Uneven Multiple-Zone
Temperatures . . . . . . . . . . . . . . 21
TCR / Thermocouple
Leads Reversed. . . . . . . . . . . . . 21
Power Failures. . . . . . . . . . . . . . 21
When the Kiln Shuts
Off Too Soon. . . . . . . . . . . . . . . 21
Appendix A:
Display Messages . . . . 22
Appendix B:
Upgrading Instructions 24
Upgrading the DTC 100, 600, 800
and 1000 Series to the Sentry
Appendix C:
User Program Records 26
Appendix D:
Quick Programming. . . 28

Safety
The warranty on your Sentry controller does not cover
damage from overfiring, regardless of the circumstances.
It is the operator’s responsibility to make sure the kiln
turns off at the end of the firing.
Follow these safety rules in addition to the ones in your
kiln or furnace manual:
When the kiln is not in
use, disconnect the power
and keep the lid or door
closed. (For larger kilns
with heavy cordsets, we
recommend a power
disconnect box near the
kiln.)
Do not leave the kiln unattended, especially
near the expected shut-off time. Do not leave a
kiln turned on at your studio while you are at
home sleeping.
Wear firing safety glasses when looking into the
peephole of a hot kiln.
Do not touch hot sides of kiln or furnace. Keep
unsupervised children away.
Install your kiln or furnace at least 12 inches
from any wall or combustible surface. (See
manufacturer’s recommendation for your
model.)
Do not open lid or door until kiln or furnace has
cooled and all switches are off.
Fire only in a well-ventilated, covered and pro-
tected area away from flammable materials.
Keep cordset away from hot sides of kiln or fur-
nace.
DANGEROUS VOLTAGE! Do not touch heat-
ing elements with anything. Disconnect kiln or
furnace before servicing.
Do not operate if the controller itself is hotter
than 158°F / 70°C. (See instructions on page 18
for checking circuit board temperature.) Never
allow the firing room temperature to exceed
110°F / 43°C. (Measure room temperature
three feet from the kiln.)
Stop a firing by pressing the STOP button, not
by disconnecting the power. In certain condi-
tions, the controller will interpreta power inter-
ruption as a power failure and turn the kiln back
on when you reconnect the power.
Place the kiln on the stand recommended by the
manufacturer. When a kiln is safety tested by
UL, the lab fires the kiln on the stand designed
for the kiln. Cinder blocks or bricks can inhibit
the flow of air under the kiln. They can also
change the kiln’s heating characteristics.
Place the kiln on a non-combustible surface.
Keep the kiln lid or door closed when the kiln is
not in use. This keeps dust out of the kiln. Also,
should someone turn on the kiln while you are
away, the closed lid will keep the heat safely in-
side the firing chamber.
Never place anything on the kiln lid, even when
the kiln is idle. If people become accustomed to
placing papers and other objects on the kiln,
they may forget and do that while the kiln is fir-
ing.
Remove all tripping hazards from around the
kiln. Keep the kiln’s supply cord out oftraffic ar-
eas.
Avoid using extension cords.
Never fire tempered glass inside a kiln. It could
explode.
Greenware, which is unfired clay, must be bone
dry before firing. Moist greenware can explode
inside the kiln, damaging the ware and the kiln.
Place a piece of greenware against the inside of
your wrist. If it feels cool, it is too wet to fire.
Store kiln shelves in a dry area. Moist shelves
can explode inside a kiln.
If you smell burn-
ing plastic, turn
the kiln off. Exam-
ine the wall outlet
and supply cord for
signs of burning.
Never place extra
insulation around
the kiln in an attempt to conserve energy. The
extra insulation can cause the wiring and the
steel case to over-heat.
4Ramp-Hold

Chapter 1
Getting Started
Room Temperature
and Humidity
It is okay to store the Sentry at sub-zero
temperatures. But before operating, raise the
room temperature to at least 32°F / 0°C.
Note: The Sentry will register sub-zero °F / °C
temperatures. However, 32°F / 0°C is the low-
est recommended operating temperature.
The circuit board is rated for 176°F / 80°C
maximum operating temperature. However,
the maximum recommended temperature is
158°F / 70°C, measured at the controller inside
the kiln switch box. To lower the temperature,
open windows and use a fan to blow air across
the kiln’s switch box louvers. (See page 18 to check circuit
board temperature.)
High humidity will not adversely affect the Sentry unless
water condenses on the circuit board. In this case, do not
firethekilnuntilthemoisturehasevaporatedfromthe
board.
Thunder Storms and
Power Surges
Unplug the kiln when not in use, especially during thun-
der storms and in areas with frequent power surges. If the
kiln is part way through a firing when a storm begins, it may
be okay to continue the firing. When the kiln shuts off, dis-
connect the power.
CAUTION: When firing the kiln during a storm, do
not leave the kiln unattended!
Time and Temperature
Display
Center Dot: Time
A center dot appears during
time display. It separates hours
from minutes (i.e. 1 hour, 30
minutes displays as 01.30). During temperature display,
the dot disappears.
Three-Light Display
The Sentry turns on the
heating elements intermit-
tently through relays. Power
output lights appear in the
right side of the display when the Sentry sends a signal to
turn on the relays.
IWhen the Sentry sends a signal to
the relays, all three lights appear.
IThe top light indicates power to
the top section of the kiln, the middle light power to the
middle section, and the bottom light power to the bot-
tom section. (Two-zone kilns: Ignore the center light.)
Note: Though power output lights are on, mechanical
problems can prevent the relays from turning on.
Single Right-Hand Dot: °C
When temperature is dis-
played in °C, a dot appears in
the lower right. In °F display, it
disappears. You can choose
between Fahrenheit and Celsius display. See page 15.
Operation Begins from the
IdLE Display
The controller displays
when you first apply
power to the kiln. Operation
begins from .Youcan’t
fire the kiln until ap-
pears.
IIf you press during a firing, will appear.
To get back to ,press .
IIf the display shows an error message such as in-
stead of , see pages 19 - 21.
I(firing completed) appears at the end of a firing.
To make appear, press any key.
IIf you do not touch the keys for one minute during pro-
gramming, the controller will go back to .The
controller will also discard the program you were enter-
ing and retain the previous program in memory.
Thermocouple Inspection
The small rod protruding into the firing chamber is the
temperature sensor, or thermocouple.
CAUTION: Bumping the thermocouple can push it
out of the firing chamber. This could cause an overfire!
The controller does not contain an alarm to detect this
type of failure. Bumping the thermocouple could also
cause inaccurate readings.
Thermocouples come in different widths. The wider the
thermocouple, the farther it should extend into the firing
chamber. A ½” - ¼” diameter thermocouple should extend
into the firing chamber about 1”. A 18” thermocouple
should extend into the chamber ½” - 58”. (Do not be con-
cerned if your thermocouple extends into the firing cham-
ber even farther.)
Keep shelves, posts and ware 1” - 1 ½” away from the
thermocouple. Keep an extra thermocouple on hand, es-
pecially if you fire hotter than 2000°F / 1093°C.
5

If you are using a portable, separate controller, you will
need to install the thermocouple onto the kiln. See the sep-
arate TnF 2 installation instructions.
Preventing an Overfire
Even though a digital controller turns off the kiln auto-
matically, you shouldmonitor the kiln during firing. This is
to prevent a possible overfire.
Remain nearby while the kiln is firing.
Check the kiln occasionally.
Set the temperature alarm (page 12) to
remind yourself to check the kiln. If you
are too far away to hear the alarm, you
might try using a baby monitor.
After the kiln fires to completion, dis-
connect the power. It is okay to turn off
the power to the controller while the
kiln cools to room temperature.
Theory of Operation
The temperature you are firing to is called
the target temperature. After the Sentry reaches the target
temperature, it can also hold that temperature.
The Sentry fires at a controlled heating rate. The rate is
figured in degrees per hour. If you selected a rate of 100°
per hour, it would take 10 hours for the furnace to reach
1000°. Rate is similar to miles per hour.
In summary, the Sentry does three basic tasks:
1) It fires at a controlled heating rate, or speed, mea-
sured in degrees of temperature change per hour.
2) It fires to a target temperature.
3) It can hold the target temperature.
The Sentry fires in segments, or stages. A segment is a
controlled heating rate to a target temperature. A segment
can also have a hold. Shown in the chart in the left column
is a segment with a target temperature of 1250°, a rate of
625°, and a hold of one hour.
The two parts of a segment:
I: The temperature changes.
I: The temperature remains the same.
Heating rate is figured in degrees per hour. The recom-
mended heating rate for the material you are firing is usu-
ally available from your supplier. It also varies
depending on the thickness of the material.
A segment can have only one ramp and
only one hold. Therefore, if you need more
than one hold, you will have to add additional
segments to the firing. Firing to a temperature
at a single rate would need only one segment.
Reasons to add more segments:
ITo change the heating rate.
ITo add a hold somewhere below the
shut-off temperature.
ITo control the cooling rate.
The diagram below shows a 3-segment firing. Two seg-
ments were used on the way up in temperature. Another
segment was added for controlled cooling.
To figure how many hours a segment will take to fire,
subtract the current temperature from the target tempera-
ture and divide the result by the heating rate. In the dia-
gram in the left column, 1250° - 80° (room temperature) =
1170 ÷ 625 = 1.87 hours.
After the Sentry has finished firing the last segment, it
will turn off power to the heating elements.
6Ramp-Hold
This segment will reach the target temperature of 1250° in 2 hours, then
hold that temperature for 1 hour.
Here is a simple 3-segment program. Segments 1 and 2 each have
a hold. Segment 3 is a controlled cooling segment.
“Rate” is how
many degrees per
hour the kiln will
climb in temper-
ature. (Or how
fast it cools
during a con-
trolled cooling.)

Chapter 2
Programming
Instructions
Before using your Sentry, read all of this
chapter. Have your controller in front of
you so that you can try out the keys as you
read.
The Stop/Back Key
You can stop a firing at any time by
pressing .
If you enter Options, you do not have to go through all
the prompts to get back out. Press to go to .
During programming, the key will take
you back one programming step with each key press, so it is
easy to make corrections.
Correcting Entries
If you enter the wrong temperature, rate, etc., while pro-
gramming, enter 0000. Then enter the correct numbers be-
fore pressing .
Canceling a New Program
If you do not touch the keys for one minute during pro-
gramming, the controller will go back to the display.
Thecontrollerwillalsodiscardtheprogramyouwereen-
tering and will retain the previous program in memory.
This is useful if you change your mind during program-
ming and decide to keep the previous program. Instead of
completing the new program, wait a minute and let the
controller return to .
Storing “User” Programs
To program the controller, must appear. From
press .will appear. The controller is ready
for you to choose a stored program or to enter a new one.
(See next page for program-
ming instructions.)
The controller can hold 4
programs in memory. They
stay in memory even when the
power is turned off. Stored
programs are numbered 1
through 4. User program 1 can
have up to 20 segments. User
programs2-4canhave10seg
-
ments each. You don’t have to
use all the segments
available—use only the number needed. Often one seg-
ment is all you will need.
When you program a firing, you will be asked to enter a
rate for each segment. Step 7, Programming Instructions,
next page, shows you how to zero out the segments you
don’t need.
When entering a program for the first time, press after
appears. Your first firing will be stored as Program
1.
Each time you store another program, select the next
available number, such as 2, at the prompt. Select-
ing a number for a new program over-writes (erases) any
program stored there. Write down your user programs for
quick reference. (Make copies of the blank form on page
26.)
Note: For repeat firings that you don’t want to inad-
vertently change, see Program Lock, page 18.
Firing a Stored User Program
After you enter a new program and the display shows
, the new program is in memory and ready to fire.
Selecting a different stored program takes only seconds:
From press .
will appear. Enter the program number (1 -
4).
If there are no changes
to the program, press
.will ap-
pear. The controller is
ready to fire your se-
lected program. To be-
gin firing, press
once.
Note: Use Program Re-
view, page 9, before firing.
See also “Repeat Fir-
ings,” page 9.
Rate
Each segment must include a rate, which is the firing
speed of that segment. We measure rate as degrees per
hour.Thisissimilartomilesperhour;justreplacemiles
with degrees. During programming, enter the rate when
appears. ( will also include the segment num-
ber: etc.)
Thediagramonthenextpageshowsthreerates.Arate
of 1000° per hour will reach 1000° in 1 hour. A rate of 500°
will reach 1000° in 2 hours. A rateof 333° will reach 1000° in
3hours.
If you want the furnace to fire at full speed, enter a rate
of 9999. See Programming Steps, step 3, next page.
7
When USER ap-
pears, the con-
troller is asking
you to select a
stored program.
If you have none
in memory, press
1andenteryour
first program.
Keep a record of
your stored pro-
grams and all
your firings.
Write down the
results of each
firing. This may
become invalu-
able later.

Note: In Program Review, a heating rate of 9999 is
displayed as . When a kiln is heated at full
power, it may overshoot the target temperature, espe-
cially in the lower range. To avoid this, add an extra
segment with a slower rate for the last 50 degrees of
temperature rise.
CAUTION: The Sentry includes error messages to
warn you when the kiln is at the wrong temperature.
Firing the kiln at full rate turns off some of these warn-
ings. See TEdE Temperature Deviation, page 17, and
HTdE High Temperature Deviation, page 20.
If you are not sure how fast to fire, remember an old fir-
ing adage: When in doubt, slow it down.
Note: At the time that you purchase the controller, the
factory can set up your controller to calculate rate in
one of three ways: 1) degrees of temperature changeper
hour 2) degrees of temperature change per minute, or
3) elapsed time needed to reach a temperature. The
normal setting is degrees per hour. If you are having
problems entering rate, check the RATE option to be
sure your controller is set for degrees per hour, page 16.
(This note applies only to 18D and later software ver-
sions. All pre-18D controllers figure rate only as de-
grees per hour. See page 18, SOFT option, to look up
software version.)
Hold
Hold is the length of time that you want the kiln to re-
main at the target temperature. Hold is also called soak or
dwell time. Hold gives the temperature time to become
more even throughout the kiln. Hold can be used in either
heating-up or cooling-down segments.
In programming step 5 (see next column), enter hold
time. When hold is set to 99.99 hours, the Sentry will re-
main at that temperature indefinitely until you press
.
When the Sentry is in hold during a firing, the display
will alternate between time left in hold and the tempera-
ture.
8Ramp-Hold
Programming Steps
Use these instructions for your first firings. Later
you may prefer “Ramp-Hold Shorthand Instruc-
tions,” back cover.
As you follow these steps, you will see values (tem-
peratures, rates, etc.) from the last firing. To use
these again, press . To program a controlled
cooling, set the segment to a lower target tempera-
ture than that of the preceding segment.
To fire without Alarm or Delay: Follow steps 1
through 7. Then press once.
Apply power to the kiln. then
will appear. (Press if does not
appear.)
Press . will appear. Enter a program
number from 1 to 4.
Press . will appear. Enter firing
rate for segment 1 (temperature change per
hour: from 1° to 9999°).
Press . (or ) will appear. En-
ter the target temperature of segment 1.
Press . will appear. Enter seg-
ment 1 hold time in hours / minutes (e.g. 12
hours, 30 minutes = 12.30). No hold = 00.00.
Press .If appears, and you have
an AOP receptacle on your kiln, use the 1 or
2 key to select ON or OFF. Press .
(For more details on AOP, see page 16.)
Continue entering values for the segments
needed. When appears for the first
segment you don’t need, press ,then
. will appear. The kiln is ready
to fire.
press . will appear.
Enter alarm temperature. (Enter to turn
alarm off.) Then press . will ap-
pear.
press . will appear. En-
ter delay time (i.e. 12 hours, 30 minutes =
12.30). Then press . will ap-
pear. (Delay zeroes out after each completed
firing.)
From press
once. will appear, then kiln tempera-
ture. If a delay was programmed, will
appear, then time remaining until start. To
stop the firing at any time, press
We recommend using Program Review (page 9)
before firing. When program fires to completion,
will appear. Press .will appear.

Repeat
Firings
To repeat the last firing,
press from .
The kiln will begin firing.
Make sure you are repeat-
ing the correct firing by us-
ing Program Review (next
page). For repeat firings
that you don’t want to inad-
vertently change, see Pro-
gram Lock, page 18.
Program Review
When you press to begin firing, the controller
will fire the program that is in active memory. Program Re-
view shows the values for that program. The program in ac-
tive memory is—
IThe program that was fired last, or
IThe program that was selected since the last firing.
Start Program Review from , or while firing, by
pressing .
Programming a
Cooling Segment
For controlled cooling, program a segment to a lower
target temperature than that of the preceding segment.
Example: You fire at a rate of 500°F per hour to 1450°F
with your first segment. Then you want the kiln to cool at a
rate of 100°F per hour down to 700°F. Here is how you
would program the two segments:
Rate Temp.
Segment °F/°C °F/°C Hold
1 500 / 277 1450 / 788 00.00
2 100 / 55 700 / 371 00.00
The first segment is the heating segment. The second
one is the cooling segment. The controller does not use mi-
nus numbers for cooling. Just enter a lower target tempera-
ture than that of the previous segment.
Ifyoupropthelidor
door for a fast cooling, pro-
gram a fast cooling rate for
that segment. If you lower
the temperature quickly by
propping the lid but pro-
gram a slow cooling rate, the
controller will just raise the
temperature again.
Example: Some glass art-
ists flash-cool the glass just
after it fuses. They open the
door a few inches to remove
heat, then close it again.
Thistakestheglassdown
rapidly through the
devitrification range. To
program a flash-cool, use a
rate of 9999. This shuts off
the heating elements during
that segment, allowing the
kiln to cool rapidly.
Note: During fast cool-
ing, do not open the door
all the way. Do not
force-cool the kiln with a
fan.
Note: See Temperature Deviation (TEdE), page 17,
for information on error codes that may appear during
“crash” cooling. To turn these codes off, program a
crash cooling rate of 9999. This turns off TEdE error
codes only for that particular segment. The TEdE
codes still work on the hold and the other segments.
Suppose you enter a cooling rate that is faster than the
kiln can cool? Depending on the rate you enter, you may
get an alarm message. (Press to turn off the alarm.)
CPLT Message: Firing
Completed
When the firing has success-
fully completed, the Sentry will
shut off power to the elements.
Then four messages will cycle
oneaftertheother:
(complete)
Firing time in hours and minutes
The temperature reached during the last segment
The current kiln temperature
Note: After the kiln fires to completion, disconnect the
power. It is okay to turn off the power to the controller
while the kiln cools to room temperature.
Note: (See
page 18 to find software version) If appears im-
mediately after you press , it is because all pro-
grammed temperatures are lower than the current kiln
temperature. If the alarm sounds (see page 12), and
then the kiln fires to completion, you will see in-
stead of . Press . will appear.
9
It is easy to pro-
gram a con-
trolled cooling.
Simply enter a
target tempera-
ture that is lower
than that of the
previous
segment.
If you repeat the
same firing pro-
gram often, use
Program Lock so
that it cannot be
inadvertently
changed. See
page 18.
CPLT means the
kiln has fired to
completion and
the heating ele-
ments are turned
off. To make
IdLE appear,
press any key.

Temperature Overshoot
When a kiln is heated too fast, it may overshoot the tar-
get temperature, especially in small kilns at lower tempera-
tures. To avoid this, add an extra segment to slow the firing.
The segment with the slower rate should begin approxi-
mately 40° - 60° below the final target temperature.
Starting a Firing in a Hot Kiln
Sometimes a firing begins in a hot kiln after a power fail-
ure or other interruption. In this case, the Sentry will begin
firing from the first segment that matches the current tem-
perature. See Power Failures, page 21.
AOP Fan
The optional AOP (auxiliary output) is a special-order
electric receptacle mounted in the kiln’s switch box. This
receptacle can power a kiln vent or external alarm. (See
Options, page 16.) During programming, will appear
for each segment ( etc.). Use the 1 and 2
keys to select On or Off for each segment. will ap-
pear only if the AOP has been activated in the AOP Op-
tion.
A Practice Program
To practice using the controller, we will enter a program
that includes three segments. The last segment is a cooling
segment.
Using the programming instructions on page 8, enter
this firing schedule. Then use Program Review to check for
accuracy.
USER = 1
RA1 = 250
°F1=750
Hd 1 = 00.00
RA2 = 900
°F 2 = 1425
Hd 2 = 00.30
RA3 = 150
°F3=750
Hd 3 = 00.00
RA4 = 0
Note: Enter 0 for the rate in segment 4. This zeroes
out all the segments past segment 3.
Chapter 3
Sample Firing
Programs
Thesesamplefiringschedulesillustratedifferentways
to program the Sentry. When designing a firing schedule
for materials you are unfamiliar with, or when using one of
these schedules, always test-fire samples first. This is be-
cause these generalized schedules may not exactly suit the
materials that you fire in your kiln.
For practice, you might want to enter these programs
even though you may never actually use them.
Heat Treating a Knife Made from
D-2HighCarbonSteel
Rate Temp.
Segment °F / °C °F / °C Hold
1 9999 1800 / 982 00.20
2 9999 400 / 204 00.00
3 500 500 / 260 5.00
Wrap the knife blade in heat treating foil. (The foil pre-
vents carbon scale from forming on the steel.)
Set the alarm to 1800°F / 982°C. Place the knife in the
kiln. Heat at FULL rate to 1800°F / 982°C. When the alarm
sounds, get ready to remove the knife. After 20 minutes of
hold time, open the furnace door, remove the knife, and
leave the door half open.
CAUTION: Wear high temperature heat-resistant
gloves when removing the knife blade from thefurnace.
Removethebladefromtheheattreatingfoil.Placethe
knife on knifeholders, which allow air to circulate around
the blade. Place a fan several feet from the blade. Point the
blade toward the fan so the air flows parallel to the blade
length. Cool the blade rapidly to room temperature.
CAUTION: If the air hits the blades sideways, the
chance of warpage increases.
Leave the kiln door half open until the temperature
drops to 400°F / 204°C. Place the knife back inside the fur-
nace. Segment 3 will heat the kiln to 500°F / 260°C. Leave
the knife in the kiln for 2 hours. Remove the knife. Let it
cool to room temperature. Place it back inside the kiln for
another 2 hours. Then remove the knife.
Glass Fusing Firing Schedule
Rate Temp.
Segment °F / °C °F / °C Hold
1 250 / 138 750 / 398 00.00
2 900 / 500 1425 / 773 00.30
3 9999 / 9999 1050 / 565 00.00
4 150 / 83 750 / 398 00.00
10 Ramp-Hold
If you fire at a
very rapid rate,
the kiln may mo-
mentarily over-
shoot the pro-
grammed target
temperature. To
avoid that, use a
slower rate.

Stained glass, 18", 2 layers, full fuse. The fusing tempera-
ture will vary depending on the brand of glass, the batch,
and even on the color. Vent the lid. Set the alarm to 500°F.
When the alarm sounds, close the lid from venting position
and insert peephole plugs.
Set the alarm again, this time to 1350°F. When it sounds,
check the glass through the peephole. When the glass fuses
to your satisfaction, write down the temperature and hold
time for future firings, and press ,then (Skip Seg-
ment).
This will advance the kiln to segment 3, a flash cooling
segment. Lift the kiln lid slightly or open the door ajar until
the temperature drops to 1050° F. Then close the door / lid.
The kiln will cool slowly through the annealing range, then
turn off.
Note: A cooling rate of 9999 (FULL) shuts off the
warning alarm (error message) that sometimes
sounds during rapid cooling. This turns off the alarm
only for that particular ramp. The alarm codes still
work on the hold and the other programmed segments.
For details about error messages, see pages 19 - 21.
Glass Slumping Firing Schedule
Rate Temp.
Segment °F / °C °F / °C Hold
1 250 / 138 750 / 398 00.00
2 900 / 500 1250 / 676 00.30
3 9999 / 9999 1050 / 565 00.00
4 150 / 83 750 / 398 00.00
Stained glass, 18", 2 fused layers, 12" circular pieces,
slumped into a bowl. Set the alarm to 500° F. When the
alarm sounds, close the lid from venting position and insert
peephole plugs.
Set the alarm again, this time to 1150° F. When it
sounds, check the glass through the peephole. When the
glass slumps into the bowl, write down the temperature
andholdtimeforfuturefirings,andpress ,then
(Skip Segment).
This will advance the kiln to segment 3, a flash cooling
segment. Lift the kiln lid slightly or open the door ajar until
the temperature drops to 1050° F. Then close the door/lid.
The kiln will cool slowly through the annealing range.
Then it will turn off and cool to room temperature.
Note: A cooling rate of 9999 (FULL) shuts off the
warning alarm (error message) that sometimes
sounds during rapid cooling. This turns off the alarm
only for that particular ramp. The alarm codes still
work on the hold and the other programmed segments.
For details about error messages, see pages 19 - 21.
Chapter 4
Other Features
The Add Time Key
This key adds 5 minutes to a hold. It is
designed for ceramists who watch witness
cones and for glass artists who inspect the
glass near the end of firing.
During a firing, press .
,andtimein
hold, will appear.
Press again. The time
shown will increase by 5
minutes.
To return to the temper-
ature display, press
or wait 1 minute.
Note: Add Time will add
5 minutes to hold even if
no hold had been pro-
grammed. After hold time displays, 5 minutes are
added with each press of the key.
Delay Fire
This delays the start of the firing by the
amount of time entered. Use it to fit a fir-
ingintoyourscheduleortotakeadvan-
tage of lower electric rates at night. Delay zeroes out after
each firing. Therefore, it must be programmed again for
each firing. The maximum delay is 99 hours and 59 min-
utes.
First, enter the program you are going to fire.
From press . Enter delay time (i.e., 5 ½ hours
= 05.30). Press .
To begin Delay, press once from .A
Delay count-down timer will appear.
Note: Press during delay to end the delay and
begin the firing. (You could also press to end the
delay and then to begin the firing.)
CAUTION: For safety, do not leave the kiln alone
during a delay or a firing. We cannot guarantee your
kiln against overfiring even though the controller is au-
tomatic. The operator assumes full responsibility for
shutting the kiln off at the proper time.
11
With the Add
Time button, you
can add time to a
hold. With the
editing feature,
you can change
both target tem-
perature and
hold.

Present Status
Press during a firing to display the
segment that is firing. One of the follow-
ing messages will appear:
I, the segment number, and rate: The Sentry is in
the ramp part of a segment. (See charts, page 6.)
Iand segment number: The Sentry is in the hold
part of a segment.
The controller returns to normal display after 5 sec-
onds.
Note: Present Status shows the actual firing rate of
the current segment instead of the rate you pro-
grammed. If you think your kiln is heating or cooling
too slowly, compare the rate shown in Present Status
with the rate you programmed for that segment. This is
another reason you should always keep a written re-
cord of your firing programs.
Note: Pre-18D software versions show the pro-
grammed rate in Present Status. Software version 18D
and later controllers show the rate actually achieved in-
stead of the rate you programmed. (See page 18, SOFT
option, to look up software version.)
Present Status is useful when firing a program that con-
tains heating and cooling segments. Without Present Sta-
tus, it might be easy to lose track of which segment is firing.
The Temperature Alarm
The alarm sounds and flashes
when the kiln reaches the alarm tempera-
ture that you enter. Use the alarm to alert
youtocheckthefusingorslumpingof
glass or to remove a knife blade from the
furnace at the end of heat treating.
You can enter only one alarm temperature at a time.
However, after the alarm beeps, you can set the alarm for
another temperature, as many times as you want, during
the firing. Entering an alarm temperature automatically
erases the previous alarm
temperature.
Note: The alarm tem-
perature that you set dur-
ing a firing must be higher
than the current display
temperature. The alarm
is designed only for higher
temperatures and not for
cooling temperatures.
After the alarm beeps,
the alarm temperature will
stay in memory for future
firings until you replace it with a new temperature.
Monitoring the Alarm from a Distance
Place an inexpensive baby monitor near the kiln. From
another location in your building, you will be able to hear
the temperature alarm beeping and the the relays clicking.
Setting the Alarm From Idle
From , press . will appear alternat-
ing with the last alarm temperature entered.
Enter alarm temperature. Press . will
appear. (If you do not want to use the alarm, set the
alarm temperature to . This setting will disable
the alarm.)
Note: Your controller’s maximum temperature is
shown in the option (page 17). If you enter an
alarm temperature that is higher than the maximum
temperature, the alarm temperature will automatically
change to the controller’s maximum temperature.
When the alarm sounds, shut it off by pressing any key
except . (Pressing while an alarm sounds will
shut off the kiln.)
Note: If the alarm sounds as soon as firing begins, it
is because the alarm was set to a temperature below the
current temperature.
Setting the Alarm During Firing
The alarm beeps while the kiln is firing. Press .
Enter the new temperature.
Press . The kiln will continue firing.
If you touch , enter a new temperature, and forget to
press , the controller will merely continue firing
without resetting the alarm.
Estimating the
Firing Cost
Note: This feature is included with software version
18D and newer controllers. To look up your software
version, see page 18.
The Sentry controller can figure the electrical cost of a
firing. Set up the controller as follows:
In the option, enter the cost of a kilowatt-hour
of electricity. See page 16.
In the option, enter the wattage for your kiln. See
page 16.
After the kiln fires to completion, will flash. Press
the key. The cost of electricity to fire the last load will ap-
pear. To return to temperature display, press .
Note: If you enter the kiln wattage in the option
but you do not enter cost per kilowatt-hour in the
option, the controller will display kilo-
watt-hours instead of firing cost.
12 Ramp-Hold
Use the alarm to
remind yourself
that the kiln is
getting close to
the shut-off tem-
perature. Always
check the kiln
before it shuts
off.

Skip Segment
Skip Segment works only during fir-
ing. It jumps the firing from the current
segment to the next one.
Note: Skip Segment does not skip from a ramp to a
hold. It skips to the next segment.
To skip a segment, press .will appear, then the
current segment. Press . (If you change your mind
and don’t want to skip that segment, don’t press af-
ter appears. Instead, press again. The firing will
continue in the same segment.)
Skip Segment skips to the ramp of the next segment
from either a ramp or hold of the current segment.
Skip Segment Example
For more examples, see Chapter 3.
IYou have pro-
grammed 1425°F for glass fusing, followed by a segment
for controlled cooling. Watching the glass through the
peephole, you notice that the glass edges have rounded
nicely at 1315°. Use Skip Segment to end the firing seg-
ment and begin the one for slow cooling.
Note: Make a note of the temperature at which the
glass fused. Program that temperature for the next fir-
ing of that type of glass.
Editing the Current
Segment
During Firing
While the kiln is firing, you can change
the target temperature and hold time of the current seg-
ment. (You can edit only the segment that is firing. To edit
other segments, wait until the firing has progressed to
those segments.)
Even if the current segment has already started its hold
time, you can still edit the segment’s target temperature.
You can raise or lower the target temperature. The con-
troller will go back out of hold and fire to the new target
temperature at the original rate. (You cannot edit the rate,
however.)
During firing, press .
The display will show the target temperature of the
current segment. Use thenumber keys to change the
temperature. Then press .
The display will then show the hold time (or 00.00 if
there is no hold time) of the current segment.
Change the time, if needed, and press . The
kiln will resume firing.
Chapter 5
Multiple-Zone
Kilns
An Overview of Multiple-
Zone Firing If you are not sure how
many zones your kiln has,
look into the firing cham-
ber. The number of thermo-
couple tips indicates the
number of zones.
In single-zone kilns, the
Sentry measures tempera-
ture from one location.
When the controller turns
on the heat, all the elements
turn on.
With two- and three-zone kilns, the Sentry measures
temperature from each individual zone. It then adjusts the
heat separately for each zone to improve temperature uni-
formity.
To maintain even temperature, the Sentry calculates
not only temperature difference between zones, but also
length of time needed to change temperature. By carefully
timing heat output, it maintains even temperature with a
minimal loss in firing speed.
Note: Multiple-zone kilns use the same programming
instructions as single-zone kilns.
Note: Firing a Ramp-Hold program at FULL rate
(9999) shuts off multiple-zone control for that firing.
The kiln then fires as a single-zone kiln.
Thermocouple Failure
In a Multiple-Zone Kiln
In a multiple-zone kiln, if a thermocouple fails, the fir-
ingwillcontinueasasingle-zonekilnsolongasonether-
mocouple still operates. will appear, alternating
with the thermocouple that failed. (See page 19 for multi-
ple-zone thermocouple error messages.)
Power Output Lights
The three lights on the right of the temperature display
turn on when the controller sends a signal to the relays.
IWhen the Sentry sends a signal to
the relays, all three lights appear.
IThe top light indicates power to
the top section of the kiln, the middle light power to the
13
Look into the
firing chamber.
The number of
thermocouple
tips indicates the
number of zones.

middle section, and the bottom light power to the bot-
tom section. (Two-zone kilns: Ignore the center light.)
Note: Though power output lights are on, mechanical
problems can prevent the relays from turning on.
IWhen a zone temperature is too low, its indicator light
will flash. The firing will continue as single-zone.
Testing Multiple-Zone
Elements
When relays or thermocouples are connected to the
wrong controller terminals, zones will show a wide temper-
ature difference. To wire the kiln properly, trace the switch
box wiring with the kiln’s wiring diagram. Also, see “Ele-
ment Test,” page 18.
Multiple-Zone Options
These options appear only on multiple-zone kilns. They
are accessed by pressing the Options key.
DIFF / Zone Temperature
Difference
View Maximum Temperature Spread
For a two-zone kiln, this option shows temperature dif-
ference between the zones. For a three-zone kiln, it shows
the highest temperature difference between any two zones.
If the temperature shown is larger than expected, go to op-
tion T123 to view the temperature of each zone.
Press repeatedly until appears.
Press .
The maximum difference in temperature between
any zones will display. (Example: = 3°)
T123 / Zone Temperature
Display
View Temperature of Each Zone
Press repeatedly until appears.
Press .
The temperature for each
zone will display one af-
ter the other, cycling for
one minute. Then nor-
mal temperature display
will return. For example:
ITop zone:
IMiddle zone:
IBottom zone:
Chapter 6
The Options
Key
The Options key gives you access to a list of special fea-
tures. With each press of the Options key, you will see the
display code for the next option.
When you find the option you want to use, press
.
Use the and keys to select changes within the
option.
After making a selection for an option, press
. The display code for the option you just
changed will appear. You are then ready to go to
the next option.
Note: If you select a change for an option but don’t
press , the change will not go into effect.
There are two ways to get out of Options and back to
:
Press .
Do nothing for 60 seconds in Options. You will au-
tomatically be taken out of the Options displayand
back to .
Note: If you are firing the kiln while in Options, press-
ing takes you out of Options and back to the fir-
ing display. But it does not stop the firing.
TCOS / Thermocouple Offset
Calibrate the Thermocouple(s)
The thermocouple is the rod protruding into the firing
chamber. It measures temperature. Thermocouples can
“drift” as they age, causing a shift in temperature readings.
Thermocouple Offset calibrates the controller to compen-
sate for drift.
Note: The thermocouple must protrude into the firing
chamber the correct distance: 1” for ½” - ¼”-wide
thermocouples, 12" for 58" - 18”-wide thermocouples.
Calibrating Thermocouple Offset
With a Digital Pyrometer
You can calibrate Thermocouple Offset using a cali-
brated digital pyrometer. One way to calibrate your pyrom-
eter is to take it to a heat treater or other location that has a
calibrated controller you can trust. Take a reading from a
furnace with your pyrometer. Either zero it out to match
the calibrated controller on the furnace, or write down the
temperature difference between your pyrometer and the
reliable source. Store your pyrometer. Use it only for cali-
14 Ramp-Hold

brating controllers. Thus, it remains a reliable calibration
standard.
Note: The temperature at which you calibrated your
digital pyrometer should be the same temperature you
use to check the controller’s temperature readout. Ex-
ample: If you took a reading from a reliable source at
2000°F, you should check your controller reading at
around 2000°F.
Mount the thermocouple of the calibrated pyrometer in
the firing chamber near the Sentry’s thermocouple. With
the Sentry on hold, compare readings between the Sentry
and the calibrated pyrometer. Adjust Thermocouple Off-
set to compensate for any temperature difference between
them.
Note: You can also return your controller to the fac-
tory to have it calibrated on certified test equipment.
Setting Thermocouple Offset
You can enter a temperature change up to 45°F / 25°C
higher or lower than the zero factory setting.
From ,press repeatedly until
appears.
Press . , or a thermocouple offset
number, will appear.
Using the and keys, enter the new offset. (See
chart below.) Press . will appear. To
return to , press .
Thermocouple Offset Settings
°F Setting °C Setting Result
C 0 C 0 No adjustment
H 1-45 H 1-25 Kiln will fire hotter
C 1-45 C 1-25 Kiln will fire cooler
Thermocouple Offset Examples
Setting Result
H 1 Kiln will fire 1° hotter
H 17 Kiln will fire 17° hotter
C 12 Kiln will fire 12° cooler
Multiple-Zone Thermocouple Offset
From ,press repeatedly until
appears.
Press . (top thermocouple) will ap-
pear.
While displays, press . The other
thermocouple(s), then , will appear with
each press of the key:
Three-zone kilns:
Two-zone kilns:
When the correct thermocouple appears, press
.
Using the and keys, enter the new offset. (See
charts above.) Press . The thermocouple you
adjusted (i.e. ) will appear. Select another
thermocouple by pressing or return to
by pressing .
CHG- / Selecting °F or °C
The controller operates in your choice of Fahrenheit or
Celsius temperature. In °C display, a lighted dot appears in
the lower right. In °F, it disappears. To switch from °F to °C
or vice versa:
From ,press repeatedly until
appears.
Press . Use the and keys to select or
.
After selecting one of the above, press . Press
to return to .
°F/°C Temperature Conversion Formula
Below are formulas for converting temperature be-
tween °F and °C. Converting a firing rate requires a differ-
ent formula than converting a firing temperature:
Firing Temperature
(Example: “Fire to 1600°F.” 1600°F = 871°C)
(°C x 1.8) +32 = °F
(°F-32) ÷1.8=°C
Firing Rate and Temperature Change
(Example: “Fire at 200°F per hour” or “Fire 200°F hotter.”
200°F = 111°C)
°C x 1.8 = °F
°F÷1.8=°C
TC / Thermocouple Type
Select Type-K, -S or -R Thermocouple
The Sentry can use Type-K, -S or -R thermocouples. If
you specialize in firings above 2200°F / 1204°C, you should
use the Type-S or -R. Type-K is best suited for tempera-
tures below 2200°F /
1204°C.
The controller cannot
detect the type of thermo-
couple installed in your
kiln. So if you change the
thermocouple to a differ-
ent type, be sure to select
the new thermocouple
type in TC option.
Note: Ask your kiln supplier if you are not sure about
the type of thermocouple in your kiln.
CAUTION: If you select Type-S or -R,
but your kiln is wired with a Type-K, your kiln will
underfire. If you select Type-K and your kiln is wired
with a Type-S or -R, your kiln will OVERFIRE. After
15
The S-Type thermocouple has a ce-
ramic sheath. Most K-Type
thermocouples have a metal sheath.
S-Type
K-Type

using the Reset (RST) option (page 18), use the TC
option to select the correct thermocouple. Reset
changes the thermocouple selection to Type-S.
From ,press repeatedly until
appears.
Press . Use the and keys to select
or .
After selecting one of the above, press .
Press to return to .
AOP / Auxiliary Outlet
Select Vent Fan or Alarm for the Auxiliary Output
The optional AOP (Auxiliary Output) is an electrical
receptacle mounted in the kiln’s switch box. This outlet can
power a kiln vent or an external alarm, such as a bell. The
AOP is a special-order option that might not be included
on your kiln.
The choices in the AOP option:
IThis choice sends power to the AOP re-
ceptacle whenever the alarm sounds. (See Alarm, page
12.) Plug in a loud bell to alert you, from a distance, that
the kiln has reached the alarm temperature. (Control-
lers with pre-18D software: Select .)
IUse this setting if your kiln does not
have the AOP outlet.
IThis option adds a
prompt for fan ( ) to each segment during pro-
gramming (page 8). (Controllers with pre-18D soft-
ware: Select .)
From ,press repeatedly until
appears.
Press . Use the and keys to select
or .
After selecting one of the above, press .
Press to return to .
RATE/TypesofRates
Note: This feature is included on controllers with
software version 18D or newer. To look up your soft-
ware version, see the SOFT option, page 18.
The standard method of programming firing rate is
degrees of temperature change per HOUR. At the factory,
we can set up your controller to calculate rate instead as de-
grees of temperature change per MINUTE, or as
ELAPSED TIME needed to reach a temperature. The
RATE option shows you which method your controller
uses:
From ,press repeatedly until
appears.
Press . You will see one of the following:
(Degrees of temperature change per hour)
(Degrees of temperature change per minute)
(Elapsed time needed to reach a temperature)
Only the factory can change the type of rate used in your
controller.
Note: If your controller uses TIME rate, enter the
hours/minutes that each segment will take to reach its
target temperature. (Example: 1 hour, 30 minutes =
01.30.)
COST / Electric Cost Per
Kilowatt-Hour
Note: This feature is included on controllers with
software version 18D or newer. To look up your soft-
ware version, see the SOFT option, page 18.
The controller can figure the cost of a firing if you enter
the cost of electricity for your area (and kiln wattage—see
next option). The cost of electricity is figured in kilo-
watt-hours (KWh). A kilowatt-hour is 1,000 watts of elec-
tricity running for 1 hour. (10 – 100-watt light bulbs glow-
ing for one hour consume 1 KWh of electricity.)
To find what the power company charges you for a kilo-
watt-hour, look at your electric bill, call your power com-
pany, or visit their website. The electric rate may vary de-
pending on the time of year and amount of electricity you
use. In the summer, rates in some areas are higher. Also,
add the other costs listed on your electric bill, such as
power transmission charges, taxes, etc.
From ,press repeatedly until
appears. Press .
From an electric bill, enter the cost of a kilo-
watt-hour. Place cents to the right of the decimal.
Round off fractions. (Example: Enter 9.25 cents
per kilowatt-hour as 00.09.) Press .
Press to return to .
Note: You can enter the cost in U. S., Canadian, or
Euro cents, British pence, Indian paisas, or any other
money system that is based upon 100 units (i.e. 100
cents = 1 dollar.) If your system is based upon 1000
units, such as the Libyan dirham, the Oman baiza, or
the Kuwait fil, divide the cost by 10. Example: Enter
140 as 00.14. Then multiply by 10 the cost of a firing
shown in the controller display.
KW / Kilowatts Used to
Calculate Firing Cost
Note: This feature is included on controllers with
software version 18D or newer. To look up your soft-
ware version, see the SOFT option, page 18.
To figure the cost to fire your kiln, the controller needs
to know how many kilowatts your kiln uses. Look at your
kiln’s electrical data plate. It is usually on the side of the
16 Ramp-Hold

switch box. The data plate lists the watts, amps, and volts. If
watts are not listed, multiply amps x volts. (Example: 15
amps x 240 volts = 3,600 watts.)
Divide the wattage of your kiln by 1000, which gives the
kilowatts. (Move the decimal point 3 spaces to the left.)
Examples:
10,800 watts ÷ 1000 = 010.8
4,800 watts ÷ 1000 = 004.8
800 watts ÷ 1000 = 000.8
EnterthatamountintheKWoption:
From , press repeatedly until
appears. Press .
The controller shows 4 digits for entering kilowatts:
. Enter kilowatts for your kiln.
Press .
Press to return to .
Note: Please do not confuse kilowatts with kilo-
watt-hours. A kilowatt is 1,000 watts. A kilowatt-hour
is 1,000 watts powered for one hour.
To view the cost of a firing, press the key after the kiln
has fired to completion and flashes.
Id / Computer ID
Enter an ID Number for Connection to a Computer
This feature is for assigning an identification number,
from 1 to 15, to the controller. It is used only for hookup to
a personal computer, which requires an optional kit.
From , press repeatedly until
appears.
Press . Use the and keys to select an ID
number from 1 to 15. Press . Press to
return to .
TEdE / Temperature Deviation
Adjust Temperature Sensitivity of Error Codes
The temperature that the controller is trying to reach, at
any given time, is called the set point. During heating or
cooling, the set point changes at the rate you programmed.
During a hold, the set point remains steady.
The Sentry shows error messages when it can’t maintain
the set point temperature. The cushion, or leeway, allowed
before an error message flashes is called Temperature De-
viation. When the temperature is off target by more than
the Temperature Deviation setting, the alarm sounds.
Temperature Deviation affects these error messages (see
page 19):
Fail to Heat
Fail to Cool
Low Temperature Deviation
Note: On controllers that have pre-18D software, the
TEdE setting also affects the HTdE High Temperature
Deviation alarm (page 20). On 18D and later control-
lers, the HTdE setting is always 100°F / 56°C.
Some people worry when ,or ap-
pears. They wonder if something is wrong with the kiln.
Here are four ways to stop the alarm messages from ap-
pearing during routine firings:
Test your kiln to find its fastest firing rate and
its slowest cooling rate. Then program the controller using
rates within the range of the kiln’s heating/cooling capac-
ity. Example: If your fastest heating rate is 600° per hour,
enter a rate no faster than 600°.
Set the deviation temperature to a higher
number in the TEdE option. The higher the number, the
less likely that an alarm message will appear.
Set the deviation temperature to 0 in the
TEdE option. This turns off the FTH, FTC and LTdE
alarms (page 19). We do not recommend a 0 setting.
Program a segment at FULL rate (9999°).
This will shut off the deviation alarms for that segment.
(However, deviation alarms will continue to work during
the hold and all other segments with slower rates.)
CAUTION: The High Temperature Deviation
(HTdE) alarm shuts off the kiln to prevent an overfire.
On controllers with pre-18D software, entering a tem-
perature deviation of 0 turns off this important alarm!
On all controllers, entering a FULL rate also turns off
this alarm for the segment with the FULL rate.
Changing the Deviation Temperature
From ,press repeatedly until
appears.
Press . Change the deviation temperature.
The higher the number, the less likely you will acti-
vate the alarms.
Press . Press to return to .
Note: The factory default TEdE setting is 100°F /
56°C.
The Fail to Heat code appears during
a firing when the kiln cannot heat as fast as programmed.
The Temperature Deviation is set to 100°F / 56°C.
TheFailtoHeatcodewillappearifthetemperatureis
100°F / 56°C or more below the set point.
SFTY / Maximum
Temperature
View the Kiln’s Maximum Operating Temperature
From ,press repeatedly until
appears. Press . The temperature displayed is the
maximum operating temperature programmed in the Sen-
try for your kiln. (This temperature is also shown on the
kiln’s electrical data plate.) It can be altered only at the fac-
17

tory. The controller will not fire hotter than that tempera-
ture. Press .Press to return to .
ELEC / Electronics
Temperature
Check the Circuit Board Temperature
High temperatures in the switch box can damage the
controller circuit board, which is rated for 176°F / 80°C
maximum operating temperature. To lower board temper-
ature,useafantoblowairacrossthekilnswitchboxinto
the louvers. (But do not blow air into the kiln’s peepholes.)
When firing several kilns, position them at least three feet
apart to allow adequate air circulation.
From or while firing, press repeatedly
until appears. Press .Thetemperatureof
the circuit board will appear. Press .Press to
return to .
CAUTION: Do not operate the kiln if the ELEC
display is above 158°F / 70°C.
LOCK / Program Lock
Make a Program Tamper-Proof
With Program Lock activated, stored programs cannot
be altered or removed from memory. Use Program Lock
for repeat firings that you don’t want to inadvertently
change.
Note: Program Lock does not save a delay setting.
While a program is locked, you can enter a new delay.
From ,press repeatedly until
appears.
Press . (locked) or (unlocked)
will appear.
To change the setting, press three times.
Press . Press to return to .
CFG / Configuration Code
Information for Technicians
From ,press repeatedly until
appears. Press . The factory configuration code will
appear. Press .Press to return to .The
configuration code can be changed only at the factory.
SOFT / Software Version
From ,press repeatedly until
appears. Press . The software version will appear.
Press .Press to return to .
TEST / Element Test
Test the Heating Elements and Relays
This test is useful when measuring the wall receptacle
voltage under load, and amperage with an ammeter. On a
multiple-zone kiln, the test helps determine if the relays
and thermocouples are wired to the correct zones. If you
test thermocouples with a cigarette lighter or other heat
source, use this option.
Single-Zone Kiln
From ,press repeatedly until
appears.
Press . will appear, alternating with
kiln temperature. The elements will turn on for
two minutes. Press any key to abort the test.
Multiple-Zone Kiln
From press repeatedly until
appears.
Press . will appear, alternating with
the temperature of the top zone. The elements will
turn on for two minutes. Then will appear,
with temperature for the middle zone, and
with temperature for the bottom zone. (A
two-zone kiln shows and displays
only.)
During the two-minute test, press any key to end a
zone test. The controller will then begin to test the
next zone.
AOP Outlet
After the above test, kilns equipped with the AOP outlet
will display for two minutes to test power to the
AOP outlet.
RST / Reset
Reset the Controller to Most Factory Defaults:
Perform Only When Requested by a Technician
Reset does the following:
ISelects Type-S thermocouple.
ISelects °F.
IErases any thermocouple offset.
IErases User programs stored in memory.
IChanges Temperature Deviation (TEdE) back to the
factory setting of 100°F / 56°C.
CAUTION: If your kiln uses a Type-K thermocouple,
the Sentry will underfire after a reset! Use the Thermo-
couple option (page 15) to select Type-K again.
From ,press repeatedly until
appears.
Press . Use the or key to select or
.
After selecting one of the above, press .
Press to return to .
18 Ramp-Hold

Chapter 7
Error
Messages
IError messages are accompanied by an alarm.
INon-interrupting messages do not stop the firing. Ter-
minating error messages do.
IFTH, FTC, and LTdE error messages are based upon
the adjustable setting in the Temperature Deviation
(TEdE) option (page 17).
Note: On controllers with pre-18D software, the
HTdE error message is also based on the TEdE option.
Non-Interrupting
Error Messages
Press to silence the alarm. (Do not press
to silence the alarm.) The error message will remain but
the kiln will continue firing. Even though the following er-
ror messages appear, the kiln will continue its normal oper-
ation. The messages are only to alert you that the kiln could
not cool or heat as fast as you had programmed. But they
will not shut off the kiln or affect the firing in any way.
Definition of “Set Point”
The temperature that the controller is trying to reach, at
any given time, is called the set point. During heating or
cooling, the set point changes at the rate you programmed.
During a hold, the set point remains steady.
FTC / Failed to Cool
IDuring a cooling-down ramp, the programmed rate is
faster than the kiln can cool. The temperature is above
the set point temperature by more than the deviation
setting. (See Temperature Deviation, page 17.) Pro-
gram a slower cooling rate.
Note: On controllers with 18D and later software:
Use Present Status to compare the actual rate of the
current segment with the rate you programmed. (See
page 12.)
FTH / Failed to Heat
IDuring a heating-up ramp, the programmed rate is
faster than the kiln can heat. The temperature is below
the set point temperature by more than the deviation
setting. (See Temperature Deviation, page 17.)
Program a slower rate. Or check for worn or burned out
elements, defective relays, low voltage and defective ther-
mocouple.
Note: On controllers with 18D and later software:
Use Present Status to compare the actual rate of the
current segment with the rate you programmed. (See
page 12.)
LTdE / Low Temperature
Deviation
IDuring a cooling-down ramp or a hold, the temperature
is below the set point temperature by more than the de-
viation setting. (See Temperature Deviation, page 17.)
Check for worn or burned out elements, defective re-
lays, low voltage and defective thermocouple.
Note: During a firing, Present Status shows the ac-
tual firing rate of the current segment instead of the
rate you programmed. If you think your kiln is heating
or cooling too slowly, compare the rate shown in Pres-
ent Status with the rate you programmed for that seg-
ment. This is another reason you should always keep a
written record of your firing programs. (Pre-18D soft-
ware versions show the programmed rate in Present
Status rather than the actual rate. See page 18, SOFT
option, to look up the software version.)
PF / Power Failure
alternating with normal display means the power
failed during firing. After power was restored, the firing re-
sumed.
TC with Lines / Multiple-Zone
Kiln Thermocouple Failure
Thekilnwillcontinuetofireaslongasatleastonether-
mocouple is working. The lines following “TC” represent
the position inside the kiln of the thermocouple(s) that
failed.
Topline=topthermocouple
Middle line = middle thermocouple
Bottom line = bottom thermocouple
Top thermocouple failed
Middle thermocouple failed
Bottom thermocouple failed
Top and middle thermocouples failed
Top and bottom thermocouples failed
Top, bottom and middle thermocouples failed
On Sentry controllers with pre-18D software, “TC” is
followed by a number and a line. You can check the soft-
ware version of your controller by using the SOFT Option.
Seepage18.
Multiple-zone controllers with 18D or earlier solftware:
TC 1¯ Top Thermocouple Failed
TC 2- Middle Thermocouple Failed
TC 3_ Bottom Thermocouple Failed
19

Terminating Error
Messages
and error messages
turn off the kiln and flash the following:
ITotal firing time in hours and minutes
IThe kiln shutoff temperature
IThe current kiln temperature
----/NoThermocouple
After the controller was plugged in, it could not detect a
thermocouple.
BAdP / Bad Programming
Causes:
IA program has been entered with 0 rate in the first seg-
ment.
IWhen you press , all programmed temperatures
are below the current kiln temperature.
ETH / Electronics Too Hot
IThe circuit board temperature is above 176°F / 80°C.
To lower board temperature, use a fan to blow air across
the kiln switch box into the louvers. (But do not blow air
into the kiln’s peepholes.) If you have morethan one kiln in
the room, place them at least 3 feet apart. Never allow the
firing room temperature to exceed 110°F / 43°C. (Measure
room temperature 3 feet away from the kiln.)
FAIL / Thermocouple Failure
The controller is no longer receiving voltage from the
thermocouple. Causes:
IDefective thermocouple
IDisconnected thermocouple lead wires
IDefective board
IElectrical noise
FTL / Firing Too Long
IThe temperature change is less than 27°F / 15°C per
hour and the firing time is two hours longer than the
current segment was programmed to fire. This message
can appear during heating-up or cooling-down seg-
ments. sometimes appears because the cooling
segment was programmed faster than the kiln could
naturally cool down.
Iwill flash if you program a cooling segment tem-
perature that is below room temperature. When
appears, press .
Check for worn or burned out elements, defective re-
lays, low voltage and defective thermocouple. Reprogram
a slower rate in heating-up and cooling-down segments.
Note: To avoid messages, try firing the kiln at a
slower rate.
Note: During a firing, Present Status shows the ac-
tual firing rate of the current segment instead of the
rate you programmed. If you think your kiln is heating
or cooling too slowly, compare the rate shown in Pres-
ent Status with the rate you programmed for that seg-
ment. This is another reason you should always keep a
written record of your firing programs. (Pre-18D soft-
ware versions show the programmed rate in Present
Status rather than the actual rate. See page 18, SOFT
option, to look up the software version.)
HTdE / High Temperature
Deviation
Causes:
IDuring a heating-up ramp or a hold, the temperature is
100°F / 56°C above the programmed temperature.
IDuring a cooling-down segment, the temperature is
100°F/ 56°C above the segment’sstartingtemperature.
IA fast rate caused the controller to overshoot the target
temperature.
IA relay is stuck in the closed position sending power to
the elements.
See “Power Failures,” next page.
Note: You can disable the HTdE alarm for a segment
by programming a FULL rate (9999°). HTdE will con-
tinue to operate during the hold and in all other seg-
ments that have slower rates.
PF1 / Power Failure
The power failed during a controlled cooling segment.
Thekilntemperaturewasbelowthelastactivecoolingseg-
ment temperature when the power came back on. The kiln
will not resume firing. See “Power Failures,” next page.
PF 2 / Power Failure
The power failed. The kiln temperature was below
212°F / 100°C when the power came back on. The kiln will
not resume firing. See “Power Failures,” next page.
PF 3 / Power Failure
The power failed. The temperature dropped 72°F / 40°C
while the power was off. The kiln will not resume firing.
See “Power Failures,” next page.
TC 2 / Thermocouple Failure
The thermocouple of a single-zone kiln failed while the
controller was at .
20 Ramp-Hold