Stafford Instruments ST215 Instruction Manual

ST215 User Handbook Page 1
ST215 Temperature Programmer
User Handbook
Issue: 2.01
Date: 09 Feb 2017
See separate handbook for Installation Instructions
© Copyright 2014 - 2017 Stafford Instruments Ltd.
www.staffordinstruments.co.uk
TAFFOR
S
D
ST215

Page ST215 User Handbook
2
At a Glance
MAIN
DISPLAY TEMPERATURE
ICON
RAMPRATEICON
TIMEICON
START/STOPKEY
SEGMENT
DISPLAY
KILNHEATING
INDICATOR
FIRINGINDICATOR
CONTROLKEYS
MIMICDISPLAY
FUSE POWERON/OFFSWITCH

ST215 User Handbook Page 3
Quick Start Guide
Switch on & wait for kiln temperature display
To run a firing program set up previously press
the ►nkey
To stop the firing at any time press the ►nkey
again
To review firing data press the ►key to enter
the programming mode
To change firing data press the ▲& ▼keys to
change the displayed value
Use the ►key again as necessary to step to
the next firing value or segment to be reviewed
or changed
To mark the end of a program set a ramp rate to
End with the ▼key
If the keyboard is locked then press the ▲& ▼
keys together & hold down for 5 seconds to un-
lock
To exit the programming mode either wait 20
seconds or press the ►nkey to start firing

Page ST215 User Handbook
4
Contents
At a Glance .................................................2
Quick Start Guide........................................3
Contents......................................................4
Features......................................................4
Turning On..................................................5
Programming ..............................................6
Firing...........................................................8
Cooling........................................................9
Operating Notes........................................10
Adjusting While Firing...............................11
Error Messages.........................................12
Other Features..........................................14
Sample Ceramics Programs.....................15
Sample Glass Programs...........................16
· 10 programs each with up to 16 segments
· 1 controlled heating / cooling ramp + soak per segment
· Soak peiods up to 99 hours 59 mins
· Ramp rates from 1 to 999°/hour + FULL
· Ideal for glass or ceramics use
· Programs can be altered while firing
· Program pause and advance facilities
· Keyboard lockable
· Delayed start facility - up to 99 hours 59 mins
· Power failure recovery
· Energy used display
· Setpoint display
· Alarm buzzer & alarm output
· °C/°F operation
Features

ST215 User Handbook Page 5
Turning On
When turned on the ST215 performs a display
test by lighting all of the display segments and
illuminating all of the front panel indicator
lamps.
The version number of the software embed-
ded within the ST215 is now displayed. If you
need technical support you might be asked for
this code together with the serial number.
Next displayed is the thermocouple type set-
ting. This should match the type of thermo-
couple fitted to the kiln and can be R, S, K or
N type (r,S,H,n).
The final display will show the kiln tempera-
ture. All other lamps should be off.
If pressing any key causes LOC to appear
then the keyboard has been locked. This is
an anti-tamper feature. Press the ▲& ▼
keys together & hold down for 5 seconds to
unlock.
During firing the right-hand decimal point
will light to show when heating power is
being applied to the kiln.
This now shows that the keyboard is UN-
LOCKED. To re-lock the keyboard press the
▲& ▼keys together & hold down for 5
seconds.
If any mimic panel lamps are on then the ST215 is firing. To stop the firing
press the ►nkey.
Note: During power up the SEGMENT display
shows the operating units (°C/°F) of the ST215
(Installer adjustable).

Page ST215 User Handbook
6
Programming
A firing segment
An ST215 firing segment comprises a ramp followed by a soak period. Two
segments can be used for simple firing (biscuit firing for example) or several
segments can be used per program for complex firing (crystal glazing or glass-
making for example).
The ST215 ramps the kiln temperature at the required ramp rate until the kiln
reaches the soak / target temperature. It then soaks (dwells) at the soak tem-
perature for the soak period. It then runs the next segment until the end of the
program is reached.
The ST215 is capable of both positive (heating) ramps and negative (cooling)
ramps - as used in glassmaking for annealing. The type of ramp is clearly
shown on the mimic display during firing.
The ramp rate is settable in the range 1°/hour to 999°/hour or FULL (full power)
or End (end of program).
The soak / target temperature is settable over the range 0 to 1400°C (2552°F).
The soak period is settable over the range 00.00 (no soak) to 99 hours 59
mins.
Note: during soaking the ST215 display alternates every 15 seconds
between kiln temperature and soak period remaining.
Cooling Ramp
HeatingRamp
SoakPeriod
SoakTemperature
(target temperature)

ST215 User Handbook Page 7
When not firing there are no indicators lit on
the mimic panel, the run indicator is off and
the display shows the current kiln
temperature.
Altering a program
The controller settings can be reviewed by pressing the ►key.
The first push of the ►key flashes the
program number display. The required firing
program can now be selected with the ▲& ▼
keys.
Note: holding down the ▲or ▼keys causes rapid change of the displayed value.
The next push of the ►key displays the ramp
rate in the range End, 1-999°/HR or FULL.
This can be altered with the ▲& ▼keys.
The heating ramp or the cooling ramp indica-
tor on the mimic panel will flash. End marks
the end of the program. FULL heats or cools as fast as possible.
The next push of the ►key displays the soak
temperature. This can be altered with the ▲
& ▼keys. The soak temperature indicator on
the mimic panel will flash.
The next push of the ►key displays the soak
period in hours:minutes. This can be altered
in the range 00:00 to 99:59 with the ▲& ▼
keys. The soak period indicator on the mimic
panel will flash.
The next push of the ►key increments the segment number digit and
firing data for the next segment can be entered.
Program data entry is terminated if End is
selected for a ramp rate with the ▼key. Pro-
gram data entry is also automatically terminat-
ed if the maximum number of segments have
been entered.
Note 2: to exit programming without cycling through all of the above steps wait 20 seconds without pressing any
keys - the ST215 will revert to the idle display. Alternatively press the ►nkey to exit programming and to begin
firing immediately.
Note 3: the ◄key can be used to reverse through the programming steps to correct errors or to exit programming
mode.
Note 1: available ramp rate displays are: End, 1 …999 & FULL. If End is shown but another segment is required
then push the ▲key to obtain the required ramp rate (in the range 1°/hr to 999°/hr). If full power is required then push
the ▲key until FULL is displayed. To mark the end of the program push the▼key until End is displayed

Page ST215 User Handbook
8
Firing
To start a firing press the ►nkey. The firing indicator lamp will flash.
Hint: it is good practice to check that the program is correct by press-
ing the ►key & checking the program number & program contents
before pressing the ►nkey to start a firing. It is also a good idea to
have a written record of the contents of the firing programs kept and
displayed near the kiln especially if there is more than one user of the
kiln.
With the firing indicator flashing an optional
start delay up to 99 hours: 59 minutes can
be entered with the ▲& ▼keys.
Information: The ST215 operates by calculating the amount of energy required by the
kiln every 30 seconds (installer adjustable). If for example 40% of full energy is
required to maintain a particular ramp rate or a particular soak temperature then the
ST215 will apply heating power to the kiln for 12 seconds every 30 seconds. The kiln
heating indicator will light for 12 seconds every 30 seconds. If the kiln has a contactor
then a loud click will be heard both when the kiln heating indicator lights up and when
it goes out. If full heating power is required then the kiln heating indicator will remain
lit. If full cooling is required the kiln heating indicator will remain off.
After 5 seconds, or immediately if the ►nkey is pressed again, the firing will
commence and the firing indicator lamp will remain lit.
To stop the firing prematurely at any time press the ►nkey again. The fir-
ing indicator lamp will go out.
Note: during ramping the ST215 will perform either controlled heating or con-
trolled cooling - as indicated on the mimic display. During soaking the
ST215 display alternates every 15 seconds between kiln temperature and
soak period remaining. At the end of each segment the segment number
display will be incremented.

ST215 User Handbook Page 9
Cooling
Upon completion of firing the ST215 lights all lamps on the mimic display and
the kiln is allowed to cool naturally.
While the kiln temperature is above 40°C the display alternates every 5 sec-
onds between the kiln temperature and HOt.
When the kiln has cooled to less than 40°C the display alternates every 5
seconds between the kiln temperature and End.
To return the ST215 back to idle condition ready for the next firing press the
►nkey (or turn off the power to the instrument).

Page ST215 User Handbook
10
If the ST215 is programmed to heat the kiln at a faster rate than the kiln is
capable of then the ST215 will turn on full power then wait until the kiln tem-
perature has risen to the correct temperature before proceeding to the next
ramp or soak segment.
Likewise if the ST215 is programmed to cool the kiln at a faster rate than the
kiln is capable of then the ST215 will apply zero power then wait until the kiln
has cooled to the correct temperature before proceeding to the next ramp or
soak segment.
Kiln too slow
Heating & Cooling Ramps
The ST215 is capable of controlled ramps for both heating and cooling. The
type of ramp required is determined by comparing the required soak temper-
ature to the soak temperature in the previous segment and is shown on the
mimic display.
►nKey Operation
If the ►nkey is pressed during a firing then the firing will be halted (not
paused). Pressing the ►nkey again will cause the ST215 to restart the
firing from the beginning. The ST215 will look at the current kiln temperature
and if this is greater than the required soak temperature then the ST215 will
automatically cool from current temperature to the soak temperature. This
may not be what is desired so the ►nkey should only be used to halt the
firing in an emergency.
The program can be paused or program data can be changed while the con-
troller is firing (see next section). This is a better option than using the ►n
key. The program advance feature is however available to recover quickly
from ►nkey operation if required.
Memory
All programs & necessary data are remembered when the ST215 is turned
off. In the event of power failure during firing the ST215 will automatically
resume firing when power is returned (this feature can be disabled: see In-
stallation Handbook).
Delayed Start
By default the delayed start time period is initialised to 00:00 for each firing.
The ST215 can however be configured to remember the delayed start time
period (see Installation Handbook).
Operating Notes

ST215 User Handbook Page 11
Program Pause Facility
WARNING - PROGRAM PAUSE
The program pause facility should be used with care. Program execution is suspended
and the kiln will be held at its current temperature. If left too long at high temperatures
kiln damage could result. Pause will automatically release after an Installer-defined
time period (default: 2 hours - see Installation Handbook).
Adjusting While Firing
Firing values can be adjusted while the ST215 is firing. Also there are pro-
gram pause and program advance features that are particularly useful for
glass work.
Adjusting Firing Values
While firing operate the ►key to select the required parameter as shown by
a flashing lamp on the mimic display. The firing value is shown on the main
display and can now be adjusted with the ▲& ▼keys in the usual way. The
contents of the current segment or any segment still to be executed can be
changed. Firing will still carry on as normal while these changes are being
made. The ST215 will return to its normal running display 20 seconds after
key presses cease (or immediately after End is displayed).
Changes made to programs in this way are stored and are used for
subsequent firings.
Program Advance Facility
While firing press and hold down the ▲key for 3 seconds to obtain the 8
(advance) function. The ST215 will sound a short beep and the executing pro-
gram will immediately advance one step as indicated by lamps on the mimic pan-
el. The effect of this is as follows:-
If ramping then the ST215 will switch to soak at the current kiln temperature.
If soaking then the ST215 will advance to the next segment if any, or else it will
end the firing.
Changes made to the operation of the ST215 in this way are temporary and are
not stored.
While firing press and hold down the ▼key to obtain the װ(pause) function. The
ST215 will sound a short beep and the executing program will pause indefinitely
at the current kiln temperature. To release the pause repeat the above action.
While paused, the kiln temperature display will
alternate periodically with a scrolling PAUSEd
display and a beep will be sounded.

Page ST215 User Handbook
12
Error Messages
Heating error. The kiln temperature is not in-
creasing as required. The kiln has been on full
power for 15 minutes but the temperature has not
increased by at least 2°C.
If the ST215 detects a problem the buzzer will sound and an error message will be
displayed. This error message will alternate with a display of kiln temperature. The
segment number display will show where the error occurred.
Possible causes: kiln door or lid not closed properly or door switch faulty or needs
adjusting. Heater element open circuit or elements too old. Electrical power phase
failure or contactor failure.
Thermocouple or thermocouple wiring open cir-
cuit. Get thermocouple and wiring checked.
Replace thermocouple if necessary.
Thermocouple reversed (kiln temperature appar-
ently less than -40°C). This is an installation
fault. Get wiring checked.
Cooling error. The kiln has been on zero power
for 30 minutes but the kiln temperature has not
fallen by at least 1°C.
Possible causes: contactor failure (contacts welded?) or thermocouple connection
intermittent or high resistance.
Kiln temperature overshoot. The kiln tempera-
ture exceeds the desired temperature by a preset
limit as shown below:-
To obtain more information on the error operate the ◄key. The first press will display
the maximum temperature reached in the firing. The second press will display the
length of time that the error has been present. The buzzer will mute.
Desired Temperature Overshoot allowed
More than 100°C but less than 200°C +50°C
More than 200°C but less than 600°C +30°C
More than 600°C +20°C
Less than 100°C +60°C

ST215 User Handbook Page 13
All these error messages cause the ST215 to terminate the firing. The alarm buzzer
will sound once per second. To reset the ST215 turn off the power to the instrument
and have the fault investigated and rectified by your installer or kiln service engineer.
Technical note: these error messages will cause the alarm relay
to open.
Note: these error messages are provided to detect kiln faults
and so offer some protection to the kiln.
Maximum firing time exceeded. The length of
the firing has exceeded an installer selectable
limit.
Maximum room temperature exceeded. The
internal temperature of the ST215 has exceeded
an installer selectable limit.
Possible causes: kiln room vent fan failure, kiln room too small, ventilation grills
blocked, damper or bung left open, controller mounted too close to kiln.
Program Error. This error message is displayed
if a potential error is detected within the firing
program when the ►nkey is pressed to start a
firing. The alarm buzzer will sound 3 times and
the segment display will show the suspect seg-
ment number. To clear this error press the ►key. The ST215 will now enter
programming mode to allow the suspect program to be viewed and altered if neces-
sary. If a fault is found then correct it. If no fault is found then press the ►nkey again
to force the firing program to start. A potential programming error is defined as a very
low ramp rate to a very low temperature. Such a programming fault might cause very
long firing times with potential kiln damage.
Firing Program Errors

Page ST215 User Handbook
14
Other Features
Energy Used & Setpoint Displays
Operate the ◄key at any time to show the amount of electrical energy used
in kWh. If pressed during a firing it shows the energy used so far. After a
firing it shows the total energy used for that firing. This information is stored
while power is off and is only reset to zero when a new firing is started. If the
value displayed is always 0.0 then the kiln power rating has not been config-
ured - see installation handbook.
Operating the ◄key a second time shows the current set-point (the temper-
ature which the ST215 is currently trying to achieve).
Keyboard Lock Facility
The keys on the ST215 can be locked so that pressing them has no effect.
This is an anti-tamper feature used to ensure that the operation of the ST215
or the program data cannot be altered by un-authorised people. The ST215
can be locked when it is idle (not firing) or while it is firing. It cannot be
locked while it is being programmed.
Power Failure Recovery
If power fails during firing then the ST215 recovers as follows:-
For power failure during start delay the ST215 times off the remaining start
delay when power returns. For power failure during ramping the ST215 con-
tinues the ramp it was previously executing. For power failure during soak-
ing the ST215 ramps back up to soak temperature at the correct ramp rate
then applies the remaining soak period. This recovery scheme can be disa-
bled if required (see installation handbook) - the ST215 will then lock up with
FAIL displayed and kiln off in the event of power failure.
Press the ▲& ▼keys together & hold
down for 5 seconds to lock or to unlock.

ST215 User Handbook Page 15
Sample Ceramics Programs
Program
Number
Program Name Seg 1
Ramp
Rate
°C/hr
Seg 1
Soak
Temp
°C
Seg 2
Ramp
Rate
°C/hr
Seg 2
Soak
Temp
°C
Seg 2
Soak
Time
hr.mn
1 Slow Bisque 60 600 FULL 1000 00.00
2 Normal Bisque 100 600 FULL 1000 00.00
3 High Bisque 100 600 FULL 1140 00.00
4 Brush-on
Earthenware Glaze
1000°C (Cone 6)
100
300 FULL 1000 00.00
5 Standard Earthenware
Glaze 1100°C 100 300 FULL 1100 00.00
6 Earthenware High
Temperature Glaze
1140°C
100
300 FULL 1140 00.00
7 Mid-Range
Stoneware Glaze
1200°C
100
300 FULL 1200 00.00
8 Standard
Stoneware Glaze
1260°C (see note)
100
300 FULL 1235 00.00
9 Onglaze 780°C 100 400 FULL 780 00.00
10 Lustre 750°C 100 400 FULL 750 00.00
Seg 1
Soak
Time
hr.mn
00.00
00.00
00.00
00.00
00.00
00.00
00.00
00.00
00.00
00.00
Seg 3
Ramp
Rate
°C/hr
End
End
End
End
End
End
End
End
End
End
Note
It has been found that a kiln controller will give greater heat work as the temperature
increases. Therefore to achieve a stoneware firing of cone 8-9 we suggest setting the
final soak temperature to 1235°C. A slight adjustment can then be made after the first
firing. It should be remembered that kiln controllers are indicators of temperature and
the effects of faster or slower firings may cause extreme variations in the end result.
This is known within ceramics as “heatwork”. Cones are measures of heatwork and it
is strongly recommended that cones are always used in conjunction with a kiln
controller to appreciate the differences between heatwork and temperature indicated
by the controller. Stoneware firings will also demonstrate the greatest potential
differences between heatwork and indicated temperature.

Page ST215 User Handbook
16
Sample Glass Programs
Program No.
Program
Description
Seg 1
Ramp
Rate
°C/hr
Seg 1
Soak
Temp
°C
Seg 1
Soak
Time
hr:mn
Seg 2
Ramp
Rate
°C/hr
Seg 2
Soak
Temp
°C
Seg 2
Soak
Time
hr:mn
Seg 3
Ramp
Rate
°C/hr
Seg 3
Soak
Temp
°C
Seg 3
Soak
Time
hr:mn
Seg 4
Ramp
Rate
°C/hr
Seg 4
Soak
Temp
°C
Seg 4
Soak
Time
hr:mn
Seg 5
Ramp
Rate
°C/hr
1 4-6mm Float Glass Fuse 150 538 00:10 FULL 840 00:20 FULL 538 00:45 182 427 00:15 End 2 4-6mm Float Glass Slump 150 538 00:00 200 700 00:15 FULL 538 00:15 182 427 00:00 End 3 6mm Bullseye™Fuse 222 677 00:30 333 795 00:10 FULL 482 01:00 83 371 00:01 End 4 6mm Bullseye™Slump 167 640 00:10 FULL 482 01:00 56 371 00:01 End - - - 5 6mm Spectrum System 96™Fuse 200 500 00:00 FULL 804 00:12 FULL 540 00:40 150 510 00:20 End 6 6mm Spectrum System 96™Slump 155 704 00:20 FULL 540 01:30 FULL 510 00:10 26 371 00:00 End 7 Bottle Firing Cycle 170 510 00:00 250 780 00:10 FULL 510 01:00 70 400 00:30 End 8 Low Stain 200 570 00:10 FULL 516 00:30 100 300 00:00 End - - - 9 High Stain 200 665 00:10 FULL 550 00:20 FULL 516 00:30 100 300 00:00 End
The ST215 is provided pre-programmed with the glass firing programs below. These programs may be modified as required.