Thomas Scientific 5300A20/F48025-TS User manual

Muffle Furnace
OPERATION MANUAL
AND PARTS LIST
Series 1285
Model Voltage Control Display
5300A20/F48025-TS 120V Single Setpoint Model °C
with OTP
5300A25/F48025-80-TS 120V 8 Setpoint Programmable Model °C
with OTP
LT1285X5 • 5/12/09

Safety Information ..............................................................................................................................................3
Alert Signals..................................................................................................................................................3
Warnings ......................................................................................................................................................3
Introduction..........................................................................................................................................................5
Intended Use ................................................................................................................................................5
eneral Usage..............................................................................................................................................5
Principles of Operation ................................................................................................................................5
eneral Specifications ........................................................................................................................................6
Models 5300A20/F48025-TS and 5300A25/F48025-80-TS ........................................................................6
Environmental Conditions ............................................................................................................................7
Unpacking ..........................................................................................................................................................8
Installation ..........................................................................................................................................................9
Site Selection................................................................................................................................................9
Electrical Connections ..................................................................................................................................9
Operation, All Models ........................................................................................................................................10
Power Switch ..............................................................................................................................................10
Cycle Light ..................................................................................................................................................10
Door Safety Switch ....................................................................................................................................10
Single Setpoint Model with OTP ......................................................................................................................11
Single Ramp & Dwell ........................................................................................................................................15
8 Segment Programmable Models with OTP....................................................................................................17
Furnace Loading ..............................................................................................................................................31
Preventative Maintenance ................................................................................................................................32
eneral Cleaning Instructions ....................................................................................................................32
Troubleshooting ................................................................................................................................................33
Maintenance and Servicing ..............................................................................................................................35
To Replace a Heating Element ..................................................................................................................35
To Replace a Chromel/Alumel Thermocouple ............................................................................................36
To Replace Door Switches (Micro-Switch) ................................................................................................37
To Realign Door Switches (Micro-Switch) ..................................................................................................37
To Replace the Controller ..........................................................................................................................38
Replacement Parts............................................................................................................................................39
Single Setpoint Models with OTP ..............................................................................................................39
8 Segment Programmable Models with OTP ............................................................................................39
Ordering Procedures ..................................................................................................................................39
Wiring Diagrams................................................................................................................................................40
Warranty Repair and Service ............................................................................................................................44
2
Table of Contents

This manual contains important operating and safety infor-
mation. You must carefully read and understand the con-
tents of this manual prior to the use of this furnace.
Your Thomas Scientific 5300A20/F48025-TS or
5300A25/F48025-80-TS Muffle Furnace has been
designed with function, reliability and safety in mind. It is
your responsibility to install it in conformance with local
electrical codes. For safe operation, please pay attention to
the alert signals throughout the manual.
Warnings
To avoid electrical shock, this furnace must:
1. Use a properly grounded electrical outlet of cor-
rect voltage and current handling capacity.
2. Be disconnected from the power supply prior to
maintenance and servicing.
3. Have the door switch operating properly.
To avoid personal injury:
1. Do not use in the presence of flammable or com-
bustible materials; fire or explosion may result.
This device contains components which may
ignite such material.
2. Caution: Hot Surface - Avoid Contact. To avoid
burns, do not touch the exterior or interior sur-
faces of this furnace during use or for a period of
time after use.
3. Always wear safety glasses or a safety shield and
high temperature gloves when loading or unload-
ing the furnace. Long sleeved, fire retardant cloth-
ing and a fire retardant apron is also recommend-
ed.
4. Refer servicing to qualified personnel.
3
Safety Information
Warning
Warnings alert you to a possibility of per-
sonal injury.
Caution
Cautions alert you to a possibility of
damage to the equipment.
Note
Notes alert you to pertinent facts and
conditions.
Hot Surface
Hot surfaces alert you to a possibility of
personal injury if you come in contact
with a surface during use or for a period
of time after use.
Alert Signals

Warning
This warning is presented for compliance with California
Proposition 65 and other regulatory agencies and only applies
to the insulation in this product. This product contains refracto-
ry ceramic, refractory ceramic fiber or fiberglass insulation,
which can produce respirable dust or fibers during disassem-
bly. Dust or fibers can cause irritation and can aggravate pre-
existing respiratory diseases. Refractory ceramic and refractory
ceramic fibers (after reaching 1000°C) contain crystalline silica,
which can cause lung damage (silicosis). The International
Agency for Research on Cancer (IARC) has classified refracto-
ry ceramic fiber and fiberglass as possibly carcinogenic ( roup
2B), and crystalline silica as carcinogenic to humans ( roup 1).
The insulating materials can be located in the door, the hearth
collar, in the chamber of the product or under the hot plate top.
Tests performed by the manufacturer indicate that there is no
risk of exposure to dust or respirable fibers resulting from oper-
ation of this product under normal conditions. However, there
may be a risk of exposure to respirable dust or fibers when
repairing or maintaining the insulating materials, or when other-
wise disturbing them in a manner which causes release of dust
or fibers. By using proper handling procedures and protective
equipment you can work safely with these insulating materials
and minimize any exposure. Refer to the appropriate Material
Safety Data Sheets (MSDS) for information regarding proper
handling and recommended protective equipment. For addi-
tional MSDS copies, or additional information concerning the
handling of refractory ceramic products, please contact the
Customer Service Department at Thomas Scientific at 1-800-
345-2100.
4
SAFETY INFORMATION
Warning
Refer servicing to qualified per-
sonnel.

Intended Use
The 5300A20/F48025-TS or 5300A25/F48025-80-TS
furnace is a general purpose laboratory and heat treat-
ing furnace. For optimum element life, Thomas
Scientific recommends observing these temperature
ranges: from 100°C (212°F) to 1093°C (2000°F) contin-
uous use or from 1093°C (2000°F) to 1200C (2192°F)
for intermittent use. Continuous use is operating the
furnace for more than 3 hours and intermittent use is
operating the furnace for less than 3 hours.
All furnaces consist of: 1) a vented heating chamber;
2) a temperature controller; and 3) a door safety switch
for operator safety.
eneral Usage
Do not use this product for anything other than its
intended usage.
Principles of Operation
The furnace chamber is heated by open coil electric
resistance elements and is insulated with ceramic fiber
insulation. The controller is located under the furnace
chamber and is well insulated from the heat generated
in the furnace chamber. A door safety switch removes
power to the heating elements whenever the furnace
door is opened. The temperature is controlled by one
of three types of controllers.
5
Introduction
Caution
Do not exceed operating temperatures
shown in “ eneral Specifications.”
Exceeding these limits will result in
severely reduced element life.

6
eneral Specifications
Models 5300A20/F48025-TS and 5300A25/F48025-80-TS
Dimensions in Inches (cm):
Chamber: 7 (17.8) W x 5 (12.7) H x 10 (25.4) D
Overall: 13.25 (33.7) W x 19 (48.3) H x 19.5 (49.5) D
Weight: 56 lb. (25.4 kg)
Electrical Ratings:
Volts: 120
Amps: 14.5
Watts: 1800
Frequency: 50/60
Phase: 1
Temperature:
Operating Range: 2000°F (1093°C) continuous
2192°F (1200°C) intermittent

7
GENERAL SPECIFICATIONS
Environmental Conditions
Operating: 17°C to 27°C; 20% to 80% relative humidity, non-condensing. Installation Category II
(overvoltage) in accordance with IEC 664. Pollution degree 2 in accordance with IEC 664.
Altitude Limit: 2,000 meters.
Storage: -25°C to 65°C; 20% to 80% relative humidity

8
1. Visually check for any physical damage
to the shipping container.
2. Inspect the equipment surfaces that are
adjacent to any damaged area.
3. Open the furnace door and remove the
packing material from inside the furnace
chamber.
4. Vacuum the chamber prior to use to
remove the insulation dust due to ship-
ment. (The 5300A20/F48025-TS and
5300A25/F48025-80-TS furnaces are
supplied with one ceramic shelf.)
5. Retain the original packaging material if
reshipment is foreseen or required.
Unpacking

9
Site Selection
Install furnace on a sturdy surface and allow adequate
space for ventilation.
Electrical Connections
The electrical ratings are located on the specification
plate on the back of the furnace. Consult Thomas
Scientific if your electrical service is different than
those listed on the specification plate. Be sure the front
power switch is in the OFF position before connecting
the furnace to your electrical supply.The
5300A20/F48025-TS or 5300A25/F48025-80-TS fur-
naces are supplied with a power cord rated at 120V,
15 amps.
Installation
Caution
Be sure ambient temperature does not
exceed 40°C (104°F). The recommended
ambient temperature is 17°C - 27°C.
Ambients above this level may result in
damage to the controller.
Warning
To avoid electrical shock, this furnace
must always use a properly grounded
outlet of correct voltage and current han-
dling capacity.
Caution
Allow at least six inches of space
between the furnace and any combustible
surface. This permits the heat from the
furnace case to escape so as not to cre-
ate a possible fire hazard.

10
Power Switch
Both the ON/OFF power switch and the digital display
will illuminate when power is switched ON. The fur-
nace will begin to heat to its controller's current set-
point. (See the instructions for your type of controller
for information on checking and setting the setpoint.)
Cycle Light
The amber cycle light will illuminate whenever the
power is being applied to the heating elements. The
cycle light will turn on and off as the furnace reaches
the setpoint.
Door Safety Switch
The door safety switch removes power from the heat-
ing elements when the door is opened. Open and
close the door a few times; note that the amber
CYCLE light will switch off when the door is opened.
If this condition is not true, consult the
Troubleshooting section before proceeding. This
check must be done when the furnace is heating and
the cycle light is illuminated.
Operation, All Models
Warning
To avoid personal injury do not use in the
presence of flammable or combustible
chemicals; fire or explosion may result.
This device contains components which
may ignite such materials.
Hot Surface
Caution: Avoid Contact. To avoid burns,
this furnace must not be touched on the
exterior or interior surfaces during use or
for a period of time after use.
Warning
To avoid electrical shock, the door safety
switch must be operating properly.
Warning
Always wear safety glasses or a safety
shield and high temperature gloves when
loading or unloading the furnace. Long
sleeved, fire retardant clothing and a fire
retardant apron is also recommended.

11
The single setpoint model w/ OTP furnace con-
troller is a single setpoint controller which provides a
single digital display to indicate the current chamber
temperature or setpoint temperature. This tempera-
ture controller features sensor break protection, self-
tuning capability and over temperature protection
(OTP) with an additional OTP relay device.
Basic Operation
When the controller is turned ON it will perform a
short self-test and then display the measured value
(process value) in the HOME DISPLAY.
Buttons and Indicators
OP1 (Output 1): Illuminates when the logic output is
ON.
OP2 (Output 2): Illuminates when the relay output is
ON (will go out during an alarm situation).
PAGE button: Allows you to select a new list of
parameters.
CROLL button: Allows you to select a parameter
within a list of parameters.
DOWN button: Allows you to decrease a value.
UP button: Allows you to increase a value.
To View or Change the
Setpoint
To view the setpoint, press and release the UP or
DOWN buttons. If you want to change the setpoint,
continue pressing until the desired setpoint value is
displayed and then release the button. A few seconds
after the button is released, the controller will accept
the new value and revert to the HOME DISPLAY.
Single Setpoint Model w/OTP
Note
If at any time you want to return to the
HOME DISPLAY, simultaneously press
the PA E and SCROLL buttons.
Single Setpoint Models
Output 1
Manual
UP ARROW
Button
Temperature
Display
Display
Window
DOWN ARROW
Button
PA E
Button SCROLL
Button
Output 2
MAN

12
To View the Display Units
From the HOME DISPLAY press the SCROLL button. The
display will show the temperature units in °C/F/K and then
return to the HOME DISPLAY. (Call Customer Service if you
require a different temperature unit.)
To View the % Output Power
From the HOME DISPLAY press the SCROLL button twice.
Press and release the UP or DOWN button to view the %
output power. This value is a read-only value and cannot be
changed.
Controller Parameters
Home display
°C: Temperature units in Celsius. Temperature units can not
be changed without entering the configuration. Contact
Customer Service if a different temperature unit is required.
OP: % output power demand.
IdHi: Deviation high alarm. Factory preset to 50.
AL List (Alarm List)
IdHi: Deviation high alarm. Factory preset to 50.
3F L: Full scale low alarm. Factory preset to -99°C.
Cannot be adjusted by end users.
Atun List (Autotune List)
tunE: One-shot autotune enable.
Pid List (Proportional, Integral, Derivative)
Pb: Proportional band (in display units). Factory preset to 5.
ti: Integral time in seconds. Factory preset to 0.48.
td: Derivative time in seconds. Factory preset to 0.8.
ACC List Code: Access code (Code needed to enter or
change the other configuration parameters which are not
normally accessible.) Not accessible.
SINGLE SETPOINT MODEL W/OTP

Alarms
The controller will flash an alarm message in the home
display if an alarm condition is detected.
2FSH: Measured value full scale high alarm. The full
scale high alarm is for furnace protection. It cannot be
accessed from the user list.
IdHi: Measured value deviation high alarm. The devia-
tion alarm is factory preset at 50°C. If the chamber tem-
perature rises to 50°C above the setpoint temperature,
this error condition will alert end users. The furnace will
continue to control temperature at the alarm setpoint,
which was defined as 50°C above the setpoint. End
users must power off the furnace and contact Customer
Service for troubleshooting assistance. Do not reset this
alarm below 20°C at any time.
S.br: Sensor Break: check that sensor is connected cor-
rectly.
L.br: Loop Break: check that the heating circuits are
working properly.
Ld.F: Heater Circuit Fault: indication of either an open or
short solid sate relay, a blown fuse, missing supply or
open circuit heater.
Sensor Break Protection
This controller provides sensor break protection in the
event the thermocouple opens. If an open thermocouple
condition occurs, the digital display will blink “S.br” and
the power to the heating element will be shut OFF (Cycle
light will extinguish).
Over-Temperature Protection
(OTP)
The OTP will be in effect during any alarm condition
when the temperature of the furnace has deviated
beyond the limit. The “Deviation High” alarm is the only
alarm value which can be changed. To change it, press
the SCROLL button until “IdHi” appears on the display.
SINGLE SETPOINT MODEL W/OTP
Note
The following alarm messages are fac-
tory default settings and may vary if you
have changed the configuration of your
controller:
IDHi: = 50°C
2FSH = 1225°C
13

14
Press the UP or DOWN button to select the OTP value
you desire. We recommend a value of 20° above your
working temperature to provide protection for your
workload.
In addition to over-temperature protection, units con-
taining a single setpoint controller w/OTP feature a
mechanical OTP relay device which disconnects power
from the elements in an alarm condition (only in fur-
naces with OTP relay).
Tuning
This controller incorporates a self-tuning feature which
determines the optimum control parameters for the
best temperature accuracy with your load and setpoint.
Use this feature the first time you use your furnace and
each time you change either your setpoint or the type
of load you are heating. Thomas Scientific recom-
mends you use this feature to provide the best temper-
ature accuracy the controller can attain. To use the tun-
ing feature:
1. Adjust the setpoint to your desired value.
2. Press the PA E button until display reads,
“Atun.”
3. Press the SCROLL button. Display will read,
“tunE.”
4. Press the UP or DOWN button to select, “on.”
5. Simultaneously press the PA E and
SCROLL buttons to return to the HOME DIS-
PLAY. The display will alternately flash
between “tunE” and the HOME DISPLAY
while tuning is in progress.
6. The controller will then turn the heating on
and off to induce an oscillation. When the
measured value reaches the required setpoint
the first cycle will end.
7. Tuning will be complete after two oscillation
cycles and then the tuner will turn itself off.
8. Normal control function will resume after the
controller calculates tuning parameters.
SINGLE SETPOINT MODEL W/OTP
Note
Furnace must be at ambient
temperature before starting a tune.
Note
Tune has completed when “tunE”
stops flashing on display.
Note
“Stat” and “Sp.rr” in Sp list must be
set to OFF or “tunE” will not initiate.

15
Functions
This type of controller has single ramp and dwell program-
ming capabilities. The Ramp and Dwell can be configured
to five different modes.
1. Mode 1 (Opt. 1) is a Ramp (if needed) to the
Setpoint temperature, a Dwell, and then a cool
down.
2. Mode 2 (Opt. 2) is the same as mode 1, except
the controller continues to heat at the Setpoint
after the Dwell has completed. (This mode does
not cool down.)
3. Mode 3 (Opt. 3) is the same as mode 1, except
the Dwell time includes the Ramp (if needed).
4. Mode 4 (Opt. 4) is the same as mode 2, except
the Dwell time includes the Ramp (if needed).
5. Mode 5 (Opt. 5) is a Dwell (delay time) before the
controller Ramps (if needed) to the Setpoint tem-
perature.
Program Overview
• A program mode can be set by changing the
“tm.OP” variable to “Opt. 1, Opt. 2, Opt. 3, Opt. 4,
or Opt. 5.
• A Ramp rate may be set by changing the “SPrr”
variable to a value. The Ramp rate units are in
degrees per minute.
• The Dwell time can be set by changing the
“dwEll” variable to the desired value. Dwell time
units are in minutes.
• The program Status can be set by changing the
“StAt” variable to “run” or “oFF.” This variable will
start or stop the program.
Single Ramp & Dwell
Mode 1 (Opt. 1)
Mode 2 (Opt. 2)
Mode 3 (Opt. 3)
Mode 4 (Opt. 4)
Mode 5 (Opt. 5)

16
Program Setup
1. Press the PA E button until the “SP” is displayed.
2. Press the SCROLL button once, “SPrr” (Ramp
Rate) will be displayed, set the desired Ramp rate
with the UP or DOWN buttons, if the ramp to set-
point feature is needed. If the Ramp rate is not
needed, then set to “OFF” with the UP or DOWN
buttons.
3. Press the SCROLL button once, “tm.OP” (Ramp &
Dwell mode) will be displayed, select the desired
mode with the UP or DOWN buttons. (Opt. 1, Opt.
2, Opt. 3, Opt. 4, Opt. 5)
4. Press the SCROLL button once, “dwEll” will be dis-
played, set the desired Dwell time with the UP or
DOWN buttons. (Dwell in minutes.)
5. Press the PA E button until the Actual tempera-
ture is displayed.
Running the Program
1. Press the SCROLL button until “StAt” is displayed,
set to “run” with the UP or DOWN buttons.
2. Press the PA E button to display Actual tempera-
ture.
Stopping the Program
Press the SCROLL button until “StAt” is displayed, set to
“oFF” with the UP or DOWN buttons.
Clearing the Flashing End
Press the PA E and SCROLL buttons at the same time.
Verifying a Running Program
Press the SCROLL button until “StAt” is displayed. The dis-
play will show “run” if the program is running, or “oFF” if it is
not running. Press the PA E button to display Actual tem-
perature.
SINGLE RAMP & DWELL
Note
The program must be stopped and
the controller must be displaying the
actual temperature before beginning
the Setup.

17
8 Segment Programmable
Model w/OTP
The 8 segment programmable controller consists of
a microprocessor based three-mode PID
(Proportional, Integral, Derivative), programmable
temperature controller with over-temperature protec-
tion and appropriate output switching devices to con-
trol the furnace. The digital readout continuously dis-
plays chamber (upper display) and setpoint (lower
display) temperatures unless the SCROLL or PA E
button is depressed. The programmable controller
can be used as a single setpoint controller or as a
programmable controller. The 8 segment digital model
enables eight segments of programming.
Basic Operation
When the controller is turned ON, it will perform a
short self-test and then change to the HOME DIS-
PLAY. The HOME DISPLAY shows the measured
temperature (process value) in the upper display and
the desired value (setpoint) in the lower display.
To Change the Setpoint
If you want to change the setpoint, press the UP or
DOWN button until the desired setpoint value is dis-
played in the lower display and then release the but-
ton.
To View Display Units
From the HOME DISPLAY press the SCROLL button.
The display will briefly show the temperature units in
°C/F/K and then return to the HOME DISPLAY. (If you
require a different temperature unit call Thomas
Scientific Customer Service.)
To View the % Output Power
From the HOME DISPLAY press the SCROLL button
twice. This value is a read-only value and cannot be
changed.
8 Segment Programmable Model with OTP
Output 1
PA E
Button
AUTO/MAN
Button
Display
Window
Upper
Display
Lower
Display
RUN/HOLD
Button
UP ARROW
Button
DOWN ARROW
Button
SCROLL
Button
Note
The controller will return to the HOME
DISPLAY if left idle for more than a few
seconds.
Note
Once the desired parameter has been
selected, depressing either the UP or
DOWN button will change the parameter
value. In all cases, the value shown on
the display is the current working value of
that parameter.

18
Buttons and Indicators
OP1 (Output 1): illuminates when the heating output of
the temperature controller is on.
AUTO/MAN: (Auto/Manual Mode): when the con-
troller is in the automatic mode the output automatically
adjusts to keep the temperature or process value at the
setpoint. The “AUTO” light will illuminate. The manual
mode has been disabled through factory configuration.
Attempts to operate in manual mode are not recom-
mended.
RUN/HOLD (Run/Hold button):
• Starts a program when pressed once—RUN
light illuminates.
• Holds a program when pressed again—
HOLD light illuminates.
• Cancels hold and continues running when
pressed again—HOLD light is off and RUN
light illuminates.
• Exits a program when the button is held down
for two seconds—RUN and HOLD lights are
off.
• At the end of a program the RUN light will
flash.
• During holdback the HOLD light will flash.
PAGE button: allows you to select a list in the user or
configuration mode.
SCROLL button: allows you to select a parameter
within a list in the user configuration mode.
UP button: allows you to increase the value in the
lower display.
DOWN button: allows you to decrease the value in the
lower display.
8 SEGMENT PROGRAMMABLE MODEL W/OTP

Controller Parameters
Home Display
°C: measured temperature in Celsius. Temperature units
can not be changed without entering the configuration.
Contact Customer Service if a different temperature unit
is required.
OP: % output power demand; displayed in lower display
(cannot be changed).
C.id: Controller identification number.
IdHi: Deviation High Alarm. Factory preset to 50.
tunE: One-shot autotune enable.
run LiSt (Program Run List)
PrG (Program): Currently running program (only used on
4x16 programmable models)
StAt (Status): Displays the program status [OFF, run
(running active program), hoLd (program on hold), HbAc
(waiting for process to catch up), End (program complet-
ed)] in the lower display. The controller will default to
“OFF.”
FASt (Fast): Fast run through program (no/YES). The
controller will default to “no.”
SEG.d (Segment): Flash active segment type in the
lower display of the home display (no/YES). The con-
troller will default to “no.”
Pro LiSt (Program Edit List)
Hb (Holdback): Press the UP or DOWN ARROW to
select the holdback type [OFF (disables holdback), Lo
(deviation low holdback), Hi (deviation high holdback) or
bAnd (deviation band holdback)] for the entire program.
The controller will default to “OFF.”
Hb.U (Holdback Units): Press the UP or DOWN
ARROW to select the holdback value (in display units).
8 SEGMENT PROGRAMMABLE MODEL W/OTP
19

20
rmP.U (Ramp Units): Press the UP or DOWN ARROW
to toggle between ramp units (SEc, min or Hour).
Controller will default to “SEc.”
dwL.U (Dwell Units): Press the UP or DOWN ARROW
to toggle between dwell units (SEc, min or Hour).
Controller will default to “SEc.”
Cyc.n (Cycle Number): Press the UP or DOWN
ARROW to set the number of program cycles (1 to 999
or cont). The controller will default to “cont.”
SEG.n (Segment Number): Press the UP or DOWN
ARROW to select the segment number (1-8).
tYPE (Type of Segment): Press the UP or DOWN
ARROW to select the segment type [End (end of pro-
gram), rmP.r = ramp rate (ramp to a specified setpoint at
a set rate), rmp.t = ramp time (ramp to a specified tem-
perature in a set time), dwEll (to maintain a constant
temperature for a set time), StEP (climb instantaneously
from current to specified temperature). The controller will
default to “End.” Other parameters used with tYPE
include; t t target setpoint), Rate (rate of temperature
increase) and dur (time to target setpoint or time to
dwell).
End.t (End Type): End segment type: dwELL (dwell con-
tinuous), rSEt (reset) and S OP (End Segment Output
power level.
AL LiSt (Alarm List)
IdHi: Deviation High Alarm. Factory preset to 50.
Atun LiSt (Autotune List)
tunE: One-shot autotune enable. Resets the PID values
automatically.
drA: Adaptive tune enable. Monitors the process variable
and resets the PID values if the process variable
exceeds the trigger level.
drA.t: Adaptive tune trigger level in display units. Range
= 1 9999.
8 SEGMENT PROGRAMMABLE MODEL W/OTP