Fisher Scientific 13-986-120A User manual

Isotemp Plus
Chromatography and General Purpose
Laboratory Refrigerator
with Alarm Version Controls
Isotemp Plus L bor tory Refriger tors
120V Versions
13-986-120A, 13-986-120RA
13-986-122A, 13-986-122RA
13-986-124A, 13-986-124RA
13-986-126A, 13-986-126RA
13-986-128A, 13-986-128RA
13-986-128SA, 13-986-128SRA
13-986-130A, 13-986-130RA
13-986-132A, 13-986-132RA
Isotemp Plus Chrom togr phy Refriger tors
120V Versions
13-986-134A, 13-986-134RA
13-986-136SA, 13-986-136SRA
13-986-138A, 13-986-138RA
13-986-140A, 13-986-140RA
Isotemp Plus L bor tory Refriger tors with Dr wers
120V Versions
13-986-134DA, 13-986-134DRA
13-986-138DA, 13-986-138DRA
13-986-140DA, 13-986-140DRA
RA – Alarm controller and chart recorder
LT2098 2 • Rev. A

Introduction..........................................................................................................................................................4
Warning ........................................................................................................................................................4
Performance Characteristics ........................................................................................................................4
Installation ..........................................................................................................................................................5
Unpacking ....................................................................................................................................................5
Visible Loss or Damage................................................................................................................................5
Concealed Loss or Damage ........................................................................................................................5
Packing List ..................................................................................................................................................6
Selecting a Location ....................................................................................................................................6
Leveling Unit ................................................................................................................................................6
Installing and Leveling Casters ....................................................................................................................7
Fluorescent Lamps ......................................................................................................................................7
Door Removal ..............................................................................................................................................7
Shelves ........................................................................................................................................................8
lectrical Connection ....................................................................................................................................9
Controls ............................................................................................................................................................10
Panel Controls ............................................................................................................................................10
Displays and Features ................................................................................................................................10
Key Switch............................................................................................................................................10
Temperature Display ............................................................................................................................11
Unit’s L D’s ..........................................................................................................................................11
Mode L D ............................................................................................................................................11
Cool L D ..............................................................................................................................................11
Alarm L D’s..........................................................................................................................................11
Keypads ..............................................................................................................................................12
Interior Light Switch..............................................................................................................................12
Operation ..........................................................................................................................................................13
Controller Set Up (Menus)..........................................................................................................................13
Temperature Setpoint ..........................................................................................................................13
Units ....................................................................................................................................................14
High Alarm Set Point ............................................................................................................................14
Low Alarm Set Point ............................................................................................................................14
Alarm Silencing Menu ..........................................................................................................................14
Alarm Test Menu ..................................................................................................................................15
Calibration Offset..................................................................................................................................15
Hold-Off Time ......................................................................................................................................15
Control Mode ..............................................................................................................................................16
Loading ................................................................................................................................................16
Temperature Digression ......................................................................................................................16
Alarms ........................................................................................................................................................17
Over Temp Alarm..................................................................................................................................17
Under Temp Alarm................................................................................................................................17
Door Ajar Alarm (swinging door models only)......................................................................................17
Power Loss Alarm ................................................................................................................................18
Alarm Silencing ....................................................................................................................................18
Alarm Test ............................................................................................................................................18
Remote Alarm Contacts ......................................................................................................................19
Open Sensor ........................................................................................................................................20
Battery Back Up ................................................................................................................................................20
Calibration Using Temperature Offset ........................................................................................................20
Convenience Outlet ....................................................................................................................................21
Chart Recorder Operation and Maintenance ....................................................................................................22
Chart Recorder Power Supply....................................................................................................................22
Changing the Chart Paper..........................................................................................................................22
Marking Systems - Mark-A-Matic Inking System........................................................................................23
Replacement Pens ....................................................................................................................................23
Recorders quipped with Fiber Tipped Cartridge ................................................................................23
2
Table of Contents

3
TABLE OF CONTENTS CONT.
Pen Arm Calibration....................................................................................................................................24
Temperature Recorder Calibration Check ..................................................................................................25
Chart Rotation Speed ................................................................................................................................25
Battery Back-up ..........................................................................................................................................26
Battery Location and Replacement ............................................................................................................26
Optional Alarm/Control Relay ....................................................................................................................26
Connection to the Relay ............................................................................................................................26
Setting the Alarms ......................................................................................................................................27
Chart Range Selection................................................................................................................................28
Recorder Specifications..............................................................................................................................29
Maintenance......................................................................................................................................................30
Cabinet Cleaning ........................................................................................................................................30
Cleaning the Condensor ............................................................................................................................30
Condensate vaporator Pan ......................................................................................................................30
Troubleshooting ................................................................................................................................................31
Replacement Parts............................................................................................................................................32
Wiring Diagrams................................................................................................................................................33
Warranty ............................................................................................................................................................36

4
This manual is intended to provide installation and operat-
ing instructions for Isotemp Plus Alarm version refrigera-
tors. The alarm version control system provides both
audible and visual indication of alarm conditions in an
easy to read display format. In addition, there are two
sets of contacts available for remote alarm switching.
Temperature and alarm set points are directly entered in
°C or °F. More about setting up the controller and all the
options are discussed in the Operating section of this
manual.
Your satisfaction and safety are important to Fisher
Scientific, a complete understanding of this unit is neces-
sary to attain these objectives.
As the ultimate user of this apparatus, it is your responsi-
bility to understand its proper function and operational
characteristics. This instruction manual should be thor-
oughly read and all operators given adequate training
before attempting to place this unit in service. Awareness
of the stated cautions and warnings, and compliance with
recommended operating parameters - together with main-
tenance requirements - are important for safe and satis-
factory operation. The unit should be used for its intended
application; alterations or modifications will void the
Warranty.
Warning
• This manual must be carefully read and thor-
oughly understood before operating the unit, fail-
ure to follow directions or precautionary meas-
ures could result in serious adverse effects.
• This equipment must be used only as specified
in these instructions. If used in a manner other
than as specified, the protection provided by the
equipment may be impaired.
• This equipment is intended for indoor use only.
• This equipment must be earth grounded for safe
operation.
• Disconnect unit line cord from power source
before performing any servicing or maintenance.
Performance Characteristics
Temperature Range: 1.0° to 12.0°C (33.8° to 53.6°F)
Temperature Stability: ±3°C
Introduction
W rning
These refrigerators are not approved
for the storage of blood or blood prod-
ucts!
W rning
As a routine laboratory precaution,
always wear safety glasses when
working with this apparatus.
W rning
This product is not intended, nor can it
be used, as a sterile or patient con-
nected device. In addition, this appara-
tus is not designed for use in Class I,
II or III locations as defined by the
National lectrical Code, unless other-
wise noted.
Wrning
Warnings alert you to a possibility of
personal injury.
C ution
Cautions alert you to a possibility of
damage to the equipment.
Note
Notes alert you to pertinent facts and
conditions.
Hot Surf ce
Hot surfaces alert you to a possibility
of personal injury if you come in con-
tact with a surface during use or for a
period of time after use.
DANGER: RISK OF CHILD NTRAP-
M NT. B FOR YOU THROW AWAY
YOUR OLD R FRIG RATOR OR
FR Z R:
• TAK OFF DOORS
• L AV TH SH LV S IN TH
PLAC SO THAT CHILDR N
MAY NOT ASILY CLIMB
INSID .
C ution
Risk of electric shock.
W rning
High voltage is supplied to PC board
when key switch is OFF.

5
Unpacking
Save all packing material if apparatus is received dam-
aged. This merchandise was carefully packed and thor-
oughly inspected before leaving our factory.
Responsibility for its s fe delivery w s ssumed by
the c rrier upon ccept nce of the shipment; there-
fore, cl ims for loss or d m ge sust ined in tr nsit
must be m de upon the c rrier by the recipient s fol-
lows:
Visible Loss or Damage
Note any external evidence of loss or damage on the
freight bill, or express receipt, and have it signed by the
carrier’s agent. Failure to adequately describe such
external evidence of loss or damage may result in the
carrier’s refusing to honor your damage claim. The carri-
er will supply the form required to file such a claim.
Concealed Loss or Damage
Concealed loss or damage refers to loss or damage,
which does not become apparent until the merchandise
has been unpacked and inspected. Should either occur,
make a written request to the carrier’s agent within 15
days of the delivery date; then file a claim with the carrier
since the damage is the carrier’s responsibility.
If you follow the above instructions carefully, we will guar-
antee our full support of your claim to be compensated for
loss from concealed damage.
DO NOT – FOR ANY R ASON – R TURN THIS UNIT
WITHOUT FIRST OBTAINING AUTHORIZATION
Installation

6
UNPACKING AND INSTALLATION
Packing List
The following items are packed in the envelope located
inside the refrigerator chamber. If any of the following
items are not present, report the missing item to your local
Fisher representative.
• Instruction Manual
• Door Lock Key
• Power Switch Key
Selecting a Location
Choose a location for the refrigerator that will provide t
le st three inches of cle r nce between the cabinet and
any adjacent vertical surface at the sides and rear.
Appropriate electrical power must be available. Locate
the refrigerator within 6 feet of the power outlet so that no
extension cord is required.
Leveling the Unit
The refrigerator must be level in order to provide ade-
quate condensation drainage as well as proper door align-
ment and operation. The refrigerator should be in its final
operating location and set so that it is firmly positioned on
the floor. There are four leveling screws, one on each cor-
ner. Level the cabinet front to rear and side-
to-side using the corner leveling screws. The front leveling
screws are accessed by removing the base grille, as
described below:
1. Remove the lower grille attaching screws.
2. Grasp the grille with both hands.
3. Lift the grille approximately 1/2”.
4. Pull grille away from the refrigerator.
Note
The refrigerator must be level in order
to provide adequate condensation
drainage as well as proper door align-
ment and operation. The refrigerator
should be in its final operating location
and set so that it is firmly positioned
on the floor..

7
Installing and Leveling Casters
Isotemp Plus refrigerators and freezers come with four
casters, which thread into the base of the unit, one in
each corner. Use the wrench provided to thread the cast-
ers completely into the base of the unit. Back the casters
in or out until the unit is level and resting on all four cast-
ers. See Figure 1.
Fluorescent Lamps
Prior to applying power to the unit, verify that all of the
internal lamps are properly installed and fully engaged in
the lamp holders. Proper lamp engagement is achieved
by rotating the lamp 90° from its insertion position until it
“snaps or “clicks into place.
Since the lamps in this unit are protected by shields, it is
necessary to physically verify that the lamp has been
rotated and locked into place.
Door Removal
(Sliding Door Models Only)
ach door has its own closing spring located at the top of
the door track. ach spring is set for proper tension. If
doors do not close properly:
1. Check for cabinet level (see above).
2. Remove the door(s) by opening slightly then lift-
ing it. While maintaining upward pressure on
the door, pull the bottom outward until it clears
the bottom track.
3. Check that spring in top track moves freely and
that bottom track is free of debris. Check that
rollers on bottom of door rotate freely.
UNPACKING AND INSTALLATION
C ution
If the unit was tilted in excess of 30
degrees, level it and do not apply
electrical power for a minimum of
12 hours.
Refrigerator
Base
Thread casters directly
into base at four corners.
Tighten using
wrench provided.
C ution
Improperly installed lamps may cause
damage to the lighting circuit.

Shelves
Shipped inside each cabinet are shelves packed in plastic
and a bag of shelf supports.
Shelf spacing is adjustable to suit user requirements.
Insert four shelf supports for each shelf into the pilasters
as shown. Note the numbers on the pilasters. Place
supports on the same numbers on each pilaster to ensure
the shelf will be level. Place the shelf on the pilasters as
shown in Fig’s 2 and 3.
Replacement shelves are available individually. See
Replacement Parts for shelf part numbers. Proper shelf
orientation is illustrated in Figures 2 & 3.
8
UNPACKING AND INSTALLATION
Note
Chromatography units include addi-
tional 1/2 shelves, which can be
used in place of the full shelves.
Figure 2
Figure 3 - Place shelves at desired height on four
shelf supports.

9
UNPACKING AND INSTALLATION
lectrical Connection
The frequency and nominal voltage requirements for the
unit are specified on the data plate, which is located on
the interiors upper left side. Only plug the unit into a
power source that meets these requirements. Low line
volt ge is often the c use of service compl ints.
With the unit running, check th t the line volt ge is
within ±10% of th t specified on the d t pl te.
The power cord on most units has a three prong (ground-
ing) plug (N MA 5-15P). This plug mates with a standard
three prong (grounding) wall receptacle (N MA 5-15R) to
minimize the potential of an electrical shock hazard.
Where necessary models are equipped with a linecord
and N MA 5-20P plug. This plug requires a N MA 5-20R
receptacle.
The customer should have the wall receptacle and circuit
checked by a qualified electrician to verify the receptacle
is properly grounded and meets power requirements
specified on the data plate.
Where a two prong wall receptacle is encountered, it is
the personal responsibility and obligation of the user to
have it replaced with a properly grounded three prong
receptacle.
During compressor start-up, the unit will momentarily
draw more current than under normal running conditions.
To avoid nuisance tripping of circuit breakers, it may be
necessary to install an HACR rated breaker.
C ution
Be sure that the power supply is the
same voltage that is specified on the
refrigerator's data plate.
W rning
Insufficient line voltage is often the
cause of compressor start-up failure.
It is strongly recommended that a
dedicated circuit, conforming to the
National lectrical Code, Article 440,
be used for powering the refrigera-
tor..
W rning
DO NOT under any circumstances cut
or remove the third (ground) prong
from the power cord. DO NOT use a
two-prong adapter plug.
W rning
For personal safety this unit must be
properly grounded.
W rning
Do not use an extension cord. Use
of an ungrounded cord or an over-
loaded circuit VOIDS the compres-
sor warranty.

10
Panel Controls
Before operation, it is necessary to become familiar with
the refrigerator controls. All the refrigerator controls are
located on the header panel. A layout of the controller
and L D’s are given below.
Displays and Features
On the right side of the header panel is the key switch.
The key switch has three positions, OFF (O), Set-up (I)
and Alarm nable (). With the refrigerator plugged in
and the key switch in the OFF position, the displays and
refrigeration system are off. The control board remains
energized in order to supply a charge to the battery.
Key Switch
Turning the key switch to the middle position energizes
the circulation fans and the controller display. When the
controller is in the Set Up mode, the menu items can be
set to the desired values. See Controller Set Up for a
description of each. Once all menu items are set, the
refrigerator can then be switched to the Alarm nable
Controls
O
I
POWER
3-Position Key Switch
Menu Keypad
I ON
O OFF
Interior Light
Switch
Up Arrow Keypad
Down Arrow Keypad
Alarm LED'S
Temperature Display
W rning
High voltage is supplied to PC board
when key switch is OFF.

position. While in the Alarm nable position, the menu
items can be viewed but not changed. The key can then
be pulled to secure the values entered.
Temperature Display
The temperature display indicates chamber temperature
while in the control mode of operation and menu titles and
values while entering menu items (see Menus).
Units L D’S
The temperature display indicates chamber temperature
in both °C and °F. The current units are indicated by the
corresponding L D located to the right of the temperature
display.
Mode L D
The Mode L D is lit when the Menu keypad has been
pressed. It indicates to the user that the controller is in
the menu selection mode.
Cool L D
The Cool L D is lit when the controller calls for cooling.
When this L D comes on the compressor should ener-
gize.
Alarm L D’S
Door Ajar - This L D is illuminated when a refrigerator
door(s) is opened. This feature is not used in the sliding
glass door models, since the circulating fans run continu-
ously and the doors are spring loaded.
Over Temp – Indicates the current chamber temperature
exceeds the high alarm temperature set point.
Under Temp – Indicates the current chamber temperature
is lower than the low alarm temperature set point.
Power Out – Indicates AC power to the refrigerator is dis-
rupted.
Alarm Test – Indicates the controller is running an alarm
test.
11
CONTROLS
Note
The key can be pulled in the Off or
the Alarm nable position.

Keypads
Menu Keypad – Pressing the Menu keypad enters the
controller into the menu selection mode, designated by
the illumination of the MOD L D. Repeatedly pressing
the Menu keypad cycles through the list of menu items
(see Menus). After the final menu, the controller returns
to the control mode and the MOD L D turns off.
Up Arrow Keypad – Increases or changes menu values.
Down Arrow Keypad - Decreases or changes menu val-
ues.
Interior Light Switch
The interior lamp(s) is controlled by a rocker switch locat-
ed on the header panel. This light may be operated any
time the cabinet power is turned on at the keyed power
switch. If the interior lamp fails, replace with the same
size and wattage lamp. DO NOT US R DUC D
WATTAG LAMPS. The reduced wattage lamps general-
ly fail to light below 60°F (15°C).
Be sure that lamps are properly installed by inserting
ends into sockets and rotating lamp 90°. Failure to install
lamps properly may cause damage to the lighting circuit.
12
CONTROLS

The refrigerator is started by inserting the power switch
key, which is found in the envelope inside the unit, into
the key switch. Turn the key to the middle (set up) posi-
tion. The internal fans will start and the display will flash
between Pout and the current chamber temperature. The
Pout (power out) display indicates to the user that the
controller has sensed a low voltage condition. This condi-
tion is normal during any start-up. See the Alarms section
for details on the Pout message. Press any keypad to
clear the Pout.
Controller Set Up (Menus)
During normal operation (control mode), the refrigerator
temperature is displayed on the 4-character display. The
compressor cycles on and off to control the chamber tem-
perature between 1.0° and 12.0°C (33.8 to 53.6°F), selec-
table by the user. The temperature set point, high and
low alarm set-points, units and display offset can be
changed while the key switch is in the setup (middle)
position. These values can be viewed but not changed
with the key switch is in the alarm position. The menu
options are explained in the following sections.
There are 8 menus to select from, each can be accessed
by pressing the Menu keypad. Pressing the Menu key-
pad once brings up the first menu, which is the tempera-
ture set point. The displays initially flash SP followed by
the last set temperature value. Pressing the Menu key-
pad again, accepts the value and displays the next menu,
units select (CF). ach menu value is entered this way.
The menus can be changed only while the key switch is
in the set up (I) position. They can be viewed but not
changed while the key switch is in the alarm enable ()
position. The individual menus are described below.
Temperature Setpoint
• Temperature Set Point (SP) – Adjustable from
1.0 to 12.0°C or 33.8 to 53.6°F. Use the
Up/Down Arrow keypads to change the temper-
ature and the Menu keypad to enter the value
and switch to the next menu.
13
Operation
Note
The Pout display is a normal occur-
rence when power is first applied to
the controller. Press any key to
clear it.

Units
• Units select (C,F) – Selects the desired temper-
ature display units in °C or °F. Use the Up
Arrow keypad to change the units from C to F.
Use the Down Arrow keypad to switch from F to
C. Press the Menu keypad to enter the units
value and continue. The appropriate units L D
will indicate the selected units.
High Alarm Set Point
• High Alarm Set Point (AH) – Use the Up/Down
Arrow keypad to adjust the value that triggers a
high alarm condition if the chamber temperature
rises above it. The high alarm temperature
range is from -33.0°C (-27.4°F) to 37.0°C
(98.6°F).
NOT : The High and Low alarm setpoints can be adjust-
ed to be within 3.5°C (6.3°F) of one another and no clos-
er.
Low Alarm Set Point
• Low Alarm Set Point (AL) – Use the Up/Down
Arrow keypad to adjust the value that triggers a
low alarm condition. The low alarm condition
occurs when the actual chamber temperature
drops below the Low Alarm Set Point. The low
alarm range is from -36.0°C (-32.8°F) to 34.0°C
(93.2°F).
Alarm Silencing Menu
• Alarm Silencing (AS) – During an alarm condi-
tion, while the key switch is in the Alarm nable
Mode, this menu allows the user to silence the
audible alarm for 5 minutes. After the AS stops
flashing, the display will show n, press the Up
Arrow keypad to change the display to y. Press
the Menu Keypad and the audible alarm will turn
off for 5 minutes.
14
CONTROLS

15
Alarm Test Menu
• Alarm Test (At) –Use the Up Arrow keypad to
change the n to H. By subsequently pressing
the Menu Keypad the controller will perform a
High Alarm Test (see Alarm Test in Alarms sec-
tion). Use the Down Arrow Keypad to change
the display to L. Pressing the Menu Keypad will
activate the Low Alarm Test. Pressing the Menu
Keypad while the display shows n returns the
unit to control mode (MOD L D off).
NOTE: While in any of the above menu options, the con-
troller will wait 15 seconds for a new value to be entered.
If there is no keypad activity within 15-seconds, the refrig-
erator will automatically shift to the Control Mode and the
Mode LED will turn off.
Calibration Offset
The two final menu items, calibration offset and hold-off
time (oS and Ho), are not accessible from the main menu.
In order to view and/or change them, the Menu keypad
must be pressed and held for 5 seconds. The calibration
offset (oS) menu will then be displayed briefly followed by
the most recent offset value.
• Display Offset (oS) – Use the Up/Down Arrow
keypads to adjust the offset value. Adjustable to
+/- 5.0°C (+/- 9.0°F). This value is added to the
temperature display to correct for differences
between actual and displayed chamber temper-
ature. See Calibration… for details. Press the
Menu keypad to enter the new value or to con-
tinue to the next menu.
Hold-Off Time
• Hold-Off (Ho) – Use the Up/Down Arrow key-
pads to adjust the Hold-Off time in minutes.
Adjustable from 3 to 10. This value represents
the delay time between compressor activations.
Increasing the Hold-Off time can help prevent
evaporator freeze-up by increasing the defrost
cycle time. Press the Menu keypad to enter the
new value and return to temperature control
mode.
CONTROLS

Control Mode
The Control Mode of operation is indicated when the
Mode L D is OFF. With the desired temperature set
point and alarm values entered, the refrigerator will then
begin to control to the set temperature. There is a time
delay between compressor activations. This delay begins
the moment the controller is energized or the moment the
compressor turns off during normal operation. The delay
is added to provide time for the system pressure to drop
before the compressor tries to start again.
Loading
Follow the guidelines below in order to provide optimal
refrigerator performance:
• When loading with critical samples, verify all
alarms and features are operating properly.
• Space samples uniformly in the chamber.
• Keep samples away from the back wall that may
obstruct airflow.
• It is best to load the refrigerator from bottom to
top. Keeping the area next to the air intake and
exhaust clear will help assure proper airflow.
Temperature Digression
By pressing the Increase keypad while the refrigerator is
in the Control Mode, the display will show the warmest
temperature recorded since the unit was energized or the
digression values were reset. Pressing the Decrease
keypad will display the coldest temperature recorded
since the unit was energized or the digression values
were reset.
To reset the temperature digression values, simply press
the Increase and Decrease keypads at the same time.
The display will show Clr, indicating the controller will
begin recording new warm and cold digressions once
more.
16
CONTROLS

17
Alarms
Alarm Version Refrigerators are equipped with audible
and visual alarms. They also feature remote alarm con-
tacts. The key switch must be in the Alarm nable posi-
tion for the audible alarm and remote alarm contacts to
activate. Alarm messages are shown on
both the temperature display and in the row of Alarm
L D’s located above the temperature display. The follow-
ing conditions will trigger an alarm:
• Chamber temperature is greater than the high
alarm set point.
• Chamber temperature is less than the low alarm
set point.
• Door has been left open for 3 minutes or more.
• AC power has been interrupted to the refrigera-
tor.
• Open sensor
NOTE: The Door Aj r Al rm is not v il ble on the
sliding gl ss door models.
Over Temp Alarm
If the refrigerator chamber temperature rises above the
High Alarm Set Point, the display will alternately flash the
refrigerator chamber temperature and “HigH”. The Over
Temp L D will be lit, the audible alarm will sound and the
remote contacts will change state.
Under Temp Alarm
If the refrigerator chamber temperature falls below the
Low Alarm Set Point, the display will alternately flash the
refrigerator chamber temperature and “Lo”. The Under
Temp L D will be lit, the audible alarm will sound and the
remote contacts will change state.
Door Ajar Alarm (swinging door models only)
When a swinging door is opened, the Door Ajar L D
lights and the display alternately flashes between the
CONTROLS

18
refrigerator temperature and “door”. If a door is opened
for 3 minutes, the audible alarm will sound and the
remote alarm contacts change state.
Power Loss Alarm
When AC power is lost, the display will alternately flash
between the current refrigerator temperature and “Pout”,
the Power Out L D will light, the audible alarm will sound
and the remote contacts will change state. When power
is restored, the display will continue flashing the “Pout”
message until it is cleared by the user by pressing any of
the keypads.
Alarm Silencing
The audible alarm can be silenced by deactivating it at
the Alarm Silence Menu (see section earlier in this manu-
al). The audible alarm will silence for 5 minutes. It will
sound again at the end of the 5 minutes if the alarm con-
dition persists. Alarm silencing does not affect the visual
alarms.
Alarm Test
The Alarm Test feature is used to verify proper alarm
operation by simulating an increase or decrease in cham-
ber temperature. The alarm test function will work for any
value of high or low alarm set points. With the key switch
in the Set Up Position the remote and audible alarms are
not activated during an alarm test, as is the case in an
actual alarm condition.
NOTE: The key switch should be in the Al rm En ble
Position in order to test ll l rm fe tures.
The procedure for testing the alarms is simple. Press the
Menu Keypad repeatedly until the display shows At (alarm
test). Momentarily, the display will change to n. Press
the Up Arrow Keypad to change the display from n to H in
order to perform a high alarm test. With the display
showing H, press the Menu Keypad again and the tem-
perature display will begin to rise until it reaches the High
Alarm Set Point. Once the set point is reached, both
audible and visual alarms should be activated (with the
key switch in alarm enable position) and the remote alarm
contacts should change state. To perform a low alarm
CONTROLS

test, simply press the Down Arrow Keypad when the dis-
play shows n. The display will then show L. Press the
Menu Keypad again in order to activate the low alarm
test.
Remote Alarm Contacts
In addition to the audible and visual alarms, there are two
sets of remote contacts on the side of the header panel,
which change state during an alarm. The upper set of
contacts provides both normally open and normally
closed switching. The lower set of contacts is used for
the Fisher Deluxe Remote Alarm System (see
Refrigerator Accessories).
19
CONTROLS
Header Panel
Remote Alarm
Contacts
Figure 4

All contacts are capable of switching up to 24 volts
AC/DC @ 2 amps. The common (C) and normally closed
(NC) contacts open during an alarm. The common (C)
and normally open (NO) contacts close during and alarm.
The contacts for the Deluxe Remote Alarm are normally
closed and open during and alarm. Figure 4 shows the
location of the remote and deluxe alarm contacts.
Remote alarm contacts are active only with the key switch
in the Alarm nable position.
Open Sensor
When the controller is unable to read from the sensor, the
display will show SnSr, indicating that a sensor error
exists The display will alternately flash SnSr and HigH.
The audible alarm will sound, the remote alarm contacts
will change state and the over temp L D will illuminate.
Battery Back Up
The Isotemp Plus Alarm Version Refrigerators are sup-
plied with a rechargeable battery back up. The battery
will continue to supply power to the controller and alarm
features in the event of a power outage. A fully charged
battery can continue powering the controller for up to 8
hours during a power failure.
The battery is recharged by the temperature controller
during normal operation. The battery should be checked
every six months and replaced when necessary (see
Replacement Parts). Check the battery by unplugging the
refrigerator and monitoring the controller operation. If the
controller does not properly activate the alarm features for
2 hours, replace the battery. Under normal operation,
the battery back up should last up to four years or 200
charge/discharge cycles.
Calibration Using Temperature
20
CONTROLS