Fisher Scientific Isotemp 500 Series User manual

Instruction Manual
Fisher Scientific
IsotempâEconomy Incubators
500 Series
Model 525D (Small)
Cat. No. 11-690-525D & -526D
Model 537D (Medium)
Cat. No. 11-690-537D & -538D
Model 550D (Large)
Cat. No. 11-690-550D & -551D

Table of
Contents
Introduction...................................................................... 1
Installation
Selecting a Location............................................... 2
Unpacking .............................................................. 2
Preparing the Incubator......................................... 3
Power Switch ......................................................... 3
Convenience Outlet .................................................3
Controls............................................................................. 4
Safety Precautions............................................................ 5
Operation .......................................................................... 5
Limit Alarms .................................................................... 6
Calibration........................................................................ 7
Service .................................................................................9
Replacing the Glass Door ......................................10
Accessing the Electronics Compartment ...............11
Replacing the Heater..............................................12
Replacing the Controller ........................................13
Replacing the Control Thermocouple....................14
Troubleshooting ...............................................................15
Replacement Parts ...........................................................16
Performance Characteristics ..........................................17
Specifications ....................................................................18
Electrical Schematic.........................................................19

Page 1 Isotemp Economy Incubators
Introduction Fisher Isotemp 500 Series Economy Incubators are available in three
sizes: small (Model 525D), medium (Model 537D) and large (Model
550D). All models provide analog, on/off control at operating
temperatures ranging from 30 °C (86°F) to 75 °C (167 °F).
Inlet air enters through a port located under the incubator floor. Heat
generated convection then gently moves the air in a vertical circulation
pattern. Exhaust air is vented through a port at the incubator top.
The Model 525D accommodates a maximum of five shelves. The Model
537D holds eight shelves, while the 550D holds up to eleven.
Isotemp incubators incorporate a variety of safety features. A safety
backup is built into the controller: if the primary heater control fails, the
Backup will maintain control at 3 °C above the set point. An alarm LED
Then indicates that the backup controller is operating the incubator. A
circuit breaker protects the incubator from power surges.
The glass door is designed to meet specification without a door gasket to
provide maximum viewing of the interior.

Isotemp Economy Incubators Page 2
Installation
Selecting a
Location Choose a location for the incubator which will provide an area
approximately 2 ft x 2 if. The bench selected must be capable of
supporting at least 120 lbs for the Model 525D, 130 lbs for the Model
537D, or 135 lbs. for the Model 550D. Appropriate electrical power must
be available. Locate the incubator within three feet of the power outlet so
that no extension cord is required.
Unpacking Fisher Isotemp®incubators are shipped in a single carton. After
unpacking, locate each item shown in the list below. Report any missing
items, by name and part number, to your Fisher branch. In the event of
shipping damage, retain the shipping material and file a claim with the
final carrier.
Item
Incubator Assembly
Model 525D (small)
Cat.# 11-690-525D 120 V, 50/60 Hz
Cat. # 11-690-526D 240 V, 50/60 Hz
Model 537D (medium)
Cat.# 11-690-537D 120 V, 60/50 Hz
Cat.# 11-690-538D 240 V, 50/60 Hz
Model 550D (large)
Cat.# 11-690-550D 120 V, 60/50 Hz
Cat.# 11-690-551D 240 V, 50/60 Hz
Shelves
Models 525D & 537D (one provided)
Model 550D (two provided)
Shelf Supports
Models 525D & 537D (two provided)
Models 550D (four provided)
Instruction Manual

Page 3 Isotemp Economy Incubators
Preparing the To prepare the incubator for operation, perform the following
Incubator procedures:
1. Install the shelf.
2. Make certain all packing material has been removed from incubator
chamber.
3. Connect the line cord to an appropriate electrical outlet.
Caution: See data plate on incubator for voltage, current and line
frequency specifications. Check that the power
requirements of the incubator will not overload the circuit
to which it will be connected.
4. The incubator is now ready for operation. No preliminary adjustments
or calibrations are required. Depending on the customer application
and customer laboratory procedures, an initial calibration may be done
at this point.
Power
Switch The 500 Series incubators feature a front panel mounted power switch
which is a combination power switch and circuit breaker, eliminating the
need for separate fusing. The circuit breaker will interrupt power in the
event of a heater malfunction.
Press the I (upper) half of the rocker-type power
switch to the in position to turn the incubator on. Press the
O (lower) half to the in position to turn off incubator
power. To reset the breaker, first place the switch to
the off position, then return it to the on position.
___________________________________________________________
Convenience
Outlet The 500 Series incubators feature a convenience electrical outlet located
inside the incubator, at the lower right of the back panel. This outlet is
rated at the same voltage as the incubator itself and is limited to a
maximum current of 5A for all models. If the current limit is exceeded,
the circuit breaker will trip. For safety, the integrity of the electrical
ground should always be maintained.

Isotemp Economy Incubators Page 4
Controls The 500 Series controller features three LED’s which indicate,
respectively, that power is being applied to the incubator heaters, an
alarm condition exists or that incubator power is on. A temperature dial,
marked in five degree increments, serves to set the incubator temperature.
Temperature Sets the incubator operating temperature in degrees
Dial Celsius (°C).
Heat Indicator Lights when power is being supplied to the incubator
heater.
Alarm Indicator Lights if the actual incubator temperature exceeds the
alarm temperature. The alarm temperature is
factory-adjusted to be 3 °C above the set temperature.
Power Indicator Lights when the power is on.

Page 5 Isotemp Economy Incubators
Safety
Precautions Before Operating the oven, always observe the
following Safety Precautions:
This unit is not explosion proof, do not use in the presence of
flammable or combustible materials; fire or explosion may result. Unit
contains components, which may ignite such materials.
Fumes and spillage from acidic solutions cause corrosion of the
stainless chamber. Care should be taken to maintain a neutral pH at all
times.
•Wear insulated gloves.
•Use tongs.
•Never stand in front of an open oven.
•Use safety goggles.
Operation The 500 Series incubators maintain a set temperature until that set
temperature is changed.
To achieve a set temperature, perform the following:
1. Rotate the temperature dial full counter-clockwise.
2. Place the power switch in the ON position. The Power indicator will
come on.
3. Rotate the temperature dial to the desired set temperature. The Heat
indicator will then come on.
4. When the actual temperature approaches the set temperature, the
Heat indicator will cycle on and off, maintaining the set temperature.
NOTE: 1. After controlling at a given temperature, if the
temperature dial is rotated CCW, the alarm indicator will
come on. This is normal operation.
2. Since this is an analog control with 5 degree
increments. The user may choose to add a thermometer
and make minor adjustments to reach a more precise
temperature setting.

Isotemp Economy Incubators Page 6
Limit The 500 Series controllers feature a deviation alarm which alerts the
Alarms operator and interrupts heater power whenever the actual incubator
temperature differs from the set temperature by more than 3 °C. This set
limit cannot be adjusted by the operator.
If the actual temperature exceeds the alarm limit, the alarm indicator LED
will light.
The reference point for the alarm is the set temperature. Any change in the
set temperature will cause a corresponding shift in the alarm temperature.
Example:
If the set temperature is 40 °C, the alarm will trip at 43 °CC. If the set
temperature is changed to 50 °C, the alarm will follow the set temperature
and trip at 53 °C.
Changing the set temperature to a value more than 3 °C below the present
incubator temperature will trip the alarm. Power is removed from the
heaters when an alarm condition occurs.

Page 7 Isotemp Economy Incubators
Calibration The 500 Series controllers are factory calibrated near the center of the
incubator’s operating range and will usually remain reasonably accurate
over a long period of usage. However, should the accuracy diminish with
time, or should the user require greater accuracy at a particular
temperature setting, the controller may be recalibrated.
The temperature controller has high and low temperature range
adjustments located under the skirt of the set temperature dial.
To recalibrate the controller, perform the following procedures:
1. Place a calibrated thermometer (preferably traceable to NIST
standards) in oven chamber.
2. Rotate temperature dial full counter-clockwise (CCW).
3. The dial line should point to 20 °C. if not, loosen the set screw
holding the dial on its shaft. Rotate shaft until dial line points to 20
°C
4. Press incubator Power switch to ON (1) position.
5. Rotate temperature dial to 40 °C. Heat indicator will COM on full,
then begin to cycle on/off as incubator approaches final temperature.
6. After the Heat indicator begins cycling, allow an additional 30
minutes for the incubator to achieve a final, stable temperature.

Isotemp Economy Incubators Page 8
7. Carefully remove the temperature dial knob without rotating it.
8. Use a thin blade screwdriver to calibrate Low Adjust. Check
thermometer reading. If reading is less than 39 °C, rotate Low
Adjust slightly to turn heater off at lower temperature. After each
adjustment allow sufficient time for incubator temperature to re-
stabilize. Repeat until thermometer reading is 40 °C ±1°C.
9. Replace temperature dial knob with pointer at 40 °C, then tighten set
screw, being careful not to rotate the dial shaft.
10. Set temperature dial to 70 °C
11. After the Heat indicator begins cycling on/off, allow an additional 30
minutes for incubator to reach a final, stable temperature. If
thermometer reads 70 °C +/- 1 °C, calibration is complete.
Otherwise continue with the following steps.
12. Carefully remove the temperature dial knob without rotating it.
13. Use a thin blade screwdriver to calibrate High Adjust. Check
thermometer reading. If reading is less than 69 °C, rotate High
Adjust slightly to turn heater off at lower temperature. After each
adjustment, allow sufficient time for incubator temperature to re-
stabilize. Repeat until thermometer reading is 70 °C +/- 1 °C.
14. Replace temperature dial knob with pointer at 70 °C, then tighten
set screw, again being careful not to rotate the dial shaft.
15. Set the temperature to 60 °C. The Alarm indicator should come on
if calibration is correct.

Page 9 Isotemp Economy Incubators
Service The following sections describe procedures for servicing the 500 Series
incubators. Replacing or adjusting the Glass Door should be within the
capabilities of most users and does not expose the operator to live
voltages (wiring). All other Service procedures involve potential
exposure to line voltage. These procedures should be undertaken only by
qualified service personnel. The next section, Accessing the Electronics
Compartment, describes procedures required of subsequent service
sections and is referenced by these later sections when required.
For Technical Assistance call: 1 [phone]
For Field Service Division Assistance call: 1 [phone]
Caution: Service procedures involve exposure to line voltage
and should be done only by qualified service
personnel. Disconnect incubator from power
source before attempting repairs.

Isotemp Economy Incubators Page 10
Replacing
The Glass
Door The Isotemp 500 Series incubators feature a glass door to allow the
chamber to be viewed with minimal heat loss. Should the glass door
become damaged, it may be replaced by following the procedures
below.
1. Loosen the set screws on outside of upper and lower hinges of the
glass door.
2. Remove old glass door and set aside.
3. Generally reverse steps above to install replacement glass door.
Adjust hinge position until gap between door and frame is roughly
equal on all sides.
Allow incubator to cool to ambient temperature
before attempting repair.
Caution:
While loosening hinge set screws, continue to
grasp the glass door. When the set screws are
loosened, the door is freed and will fall out if not
held.
Caution:

Page 11 Isotemp Economy Incubators
Accessing the To access the electronics compartment, proceed as follows:
Electronics
Compartment
1. Disconnect power cord from the electrical outlet.
Caution: Allow incubator to cool to ambient temperature
before attempting repair.
Caution: Service procedures requiring access to the
electronics compartment involve exposure to line
voltage and should be done by qualifled service
personnel. Disconnect incubator from power before
attempting repairs.
2. Remove two screws from top of incubator securing bezel to cover.
3. Grasp bezel and pull top outward. The bezel bottom will disengage
from the fascia.
4. Rotate bezel upward an lay face back on top of incubator.
Bezel screws on top
Heater Cover

Isotemp Economy Incubators Page 12
Service procedures requiring access to the
Caution: electronics compartment involve exposure to line
voltage and should be done by qualified service
p
ersonnel. Disconnect incubator from power
before attempting repairs.
Replacing To replace a defective heater, proceed as follows:
the Heater
1. Disconnect power cord from the electrical outlet.
Caution:
Allow incubator to cool to ambient temperature
before attempting repair.
2. Remove the two screws that secure the heater cover. Remove the
cover by lifting and sliding it forward. It may be necessary to use a
flat-blade screwdriver to assist in lifting the cover upward. Set heater
cover aside.
3. Remove the two nuts and lock washers securing the heater
leads, then pull the lead terminals off the heater studs.
4. Remove the two screws securing heater to cabinet. Slide heater for-
ward to disengage back heater clips, lift back of heater up, then
slide heater back and lift out
5. Install replacement heater and reassemble incubator by generally
reversing the steps above.

Page 13 Isotemp Economy Incubators
Caution: Service procedures requiring access to the
electronics compartment involve exposure to line
voltage and should be done by a qualified service
personnel. Disconnect incubator from power before
attempting repairs.
Replacing To replace a defective controller, proceed as follows:
the
Controller
1. Complete the procedures discussed in Accessing the Electronics
Compartment.
2. Remove temperature dial knob.
3. Locate three push-on terminals at right hand side of controller board
(heater wire, two power wires). Disconnect the three lead wires by
pulling up an doff terminals. Note connections for later re-assembly.
4. Remove four screws w3hich mount the controller board to the bezel.
Lift out board.
5. Loosen set screws in two-position terminal at front of controller
board and disconnect thermocouple wires.
6. Install replacement controller by generally reversing the steps above.
Check switch DSl setting:
Caution: When replacing the temperature dial, first rotate the
dial shaft full counter-clockwise. Then replace knob
with pointer at the 20 degree mark.

Isotemp Economy Incubators Page 14
Caution: Service procedures requiring access to the electronics
compartment involve exposure to line voltage and
should be done by qualified service personnel.
Disconnect incubator from power before attempting
Repairs.
Replacing To replace a defective control thermocouple, proceed as follows:
the Control
Thermocouple
1. Complete the procedures discussed in Accessing the Electronics
Compartment.
2. Remove thermocouple wires from 2-terminal connector on circuit
board by loosening two securing screws.
Observe position in terminal for each lead.
Note: When re-connecting, be certain to observe polarity.
Compare with polarity indication on
controller housing. For thermocouples, the red wire is
negative and yellow positive.
3. On lower back wall of incubator, locate two clips which hold the
thermocouple in place. Remove thermocouple from clip.
4. Pull defective thermocouple forward into incubator chamber,
exposing roughly a 6-inch section of the thermocouple wire.
5. Cut the thermocouple wire to remove the thermocouple sheath.
6. Securely loop together the cut end of the defective thermocouple
with the two leads of the replacement thermocouple. Wrap masking
tape over the length of the loops to secure them.
7. Gently pull the defective thermocouple out through the electronics
compartment while guiding (“fishing”) the replacement
thermocouple into place.
8. Generally reverse the above steps to complete installation of new
thermocouple and reassemble incubator.
9. Align thermocouple in clips such that tip of thermocouple sheath is
positioned over the edge of the third hold in the heater cover,
counting from the left.

Page 15 Isotemp Economy Incubators
Trouble-Shooting Table
This table is intended to assist in the resolving incubator problems by
relating symptoms to their likely causes. The service discussed below is
beyond the scope of most users and should be performed by qualified and
trained personnel.
Symptom Probable Cause Action
No power Unit not plugged in or turned on. Plug in or turn on.
Defective circuit breaker. Replace circuit breaker.
Incubator temperature Defective control thermocouple Replace control thermocouple
erratically high
Failure to heat Set temperature less than Refer to Operation Section
actual temperature
Defective control thermocouple Replace control thermocouple
Poor heater connections Tighten connections at terminal strip
Defective heater element Check heater resistance on schematic
at back of manual. Replace heater
unless approximately same as
schematic.
Defective controller Replace controller
Alarm LED stays on and Set temperature has been Wait for actual temperature to cool to
control is higher than set changed to a value less than the set temperature
temperature the high alarm limit
Defective control thermocouple Replace control thermocouple
Defective controller Replace controller

Isotemp Economy Incubators Page 16
Replacement Replacements for incubator parts may be ordered, by part number, from
Parts Fisher Sales/Parts @ 1-800-766-7000.
Item Part Number (ref)
Line Cord and Plug
Models 525D, 537D, & 550D SPN 06643 (LINE)
(120 V)
Models 525D, 537D, & 550D SPN 95704
(240 V International)
Temperature Controller
120 V SPN 95913 (CTRL)
240 V SPN 95914
Thermocouple Assembly SPN 95603 (TC)
Shelf Fits All Models) 13-247S
Shelf Support (Need Two per Shelf) SPN 95635
Heater Assembly
Models 525D & 537D (120 V) SPN 95693 (HTR)
Models 525D & 537D (240 V) SPN 95734
Model 550D (120 V) SPN 95694
Model 550D (240 V) SPN 95735
Circuit Breaker
Single-Pole (120 V) SPN 95764 (S1)
Double Pole (240 V) SPN 95766