Forma Laboratory Refrigerators 34830H63 Rev. A a & d voltages

4

Thermo Scientific Forma Laboratory Refrigerators

Installation and Operation

6

Control Panel

Figure 3.  Refrigerator Control Panel

6.1

Control Panel Features

The control panel is located on the top right side of your 

refrigerator. You can use the three pushbuttons (#5, #8, and #9 in 

Figure 3) to change the temperature display (#1) or to adjust 

temperature and alarm setpoints. The thermometer display (#2) 

provides a quick visual indicator of current cabinet temperature 

and alarm conditions.

Before starting up your refrigerator, take some time to review the 

control panel functions:

1. Main temperature display — during normal operation, shows 

cabinet temperature in degrees Celsius, as measured by the 

sensor inside the cabinet. You can use the buttons to display 

other values such as setpoints and extreme values. The 

number in the main display flashes when you are changing a 

value. 

2. Thermometer — shows cabinet temperature and alarm 

conditions. There are 10 horizontal bars: 9 are displayed 

during normal operation, the tenth (top) bar indicates a warm 

alarm condition. The number of bars illuminated indicates 

approximate cabinet temperature. Depending on alarm 

settings, 4 or 5 bars illuminated indicate that the cabinet is at 

setpoint. 

For example, suppose that the cabinet temperature setpoint is 

+4ºC and that the warm and cold alarm setpoints are 8ºC and 

0ºC. Then the number of bars illuminated indicates cabinet 

temperature as follows:

bulb only 0ºC (cold alarm)

6 bars

4.8

1 bar

0.8

7 bars 

5.6

2 bars

1.6

8 bars

6.4

3 bars

2.4

9 bars

7.2

4 bars

3.2

10 bars 8 (warm alarm)

5 bars

4 (setpoint)

When cabinet temperature exceeds the warm alarm setpoint, 

the top bar of the thermometer flashes. When temperature is 

lower than the cold alarm setpoint, the bulb flashes.

When you are in programming mode (described in Table 2) 

the thermometer shows the setpoint value you are changing.

3. Power failure — illuminated when the main power supply is 

interrupted. In this case the audible alarm also sounds.

4. Service required —illuminated when the controller is in 

service programming mode or when simulated warm or cold 

alarm conditions are failing to occur during an alarm test.

5. Increase — pushbutton used to increase setpoint values in 

programming mode and for various display functions.

6. Door ajar — illuminated when the refrigerator door is open 

and the alarm is activated (key switch turned to the alarm 

position). (This feature is not available for 45 ft

3

 sliding glass 

door models.)

7. Battery low — illuminated when the backup battery is low.

8. Decrease — pushbutton used to decrease setpoint values in 

programming mode and for various display functions.

9. Scan — pushbutton used to change the main display and for 

various other functions.

10. Audible alarm — illuminates during warm and cold alarm 

conditions.

For full descriptions of display, programming, and service 

functions, refer to Tables 2, 3, and 4 on page 5. 

Key Switch

1

3

4

5

6

7

8

2

10

9

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5

Thermo Scientific Forma Laboratory Refrigerators

Installation and Operation

6.2

Display Functions

Table 2. 

Control Panel Display Functions (including optional alarm functions)

6.3

Alarm Setpoints

To enter programming mode, press Scan, hold for 5 seconds, and release. The first two values displayed are the warm and cold alarm 

setpoints. Note that the alarm setpoints cannot be adjusted when the key switch is in the alarm position.

Table 3. 

Alarm Setpoint Programming Functions (with Alarm Option Only)

6.4

Service Mode Parameters

When the key switch is not turned to third (alarm) position, you can access service parameters by entering programming mode and 

pressing Scan for an additional 5 seconds. On release of the button, the display will go blank, then display “SEr” with the service 

wrench icon illuminated. Then the firmware checksum (read-only) will be displayed for about 4 seconds. Pressing Scan repeatedly 

scrolls through the available service functions. While you are in service mode, the wrench icon is illuminated. For any flashing 

parameter you can use

 

 

and

 

 to adjust the value

.

CAUTION!

Resetting any of the following parameter values could adversely affect the performance of your refrigerator. 

These settings very rarely need to be changed for normal +4ºC operation. Be sure to call Service before making any 

adjustments to parameter values.

Table 4. 

Programming Parameters

Function

Meaning

Sequence

Display

Normal operation

Default display while refrigerator 

is running

 —

Temperature display, thermometer show cabinet temperature.

Cold excursion

Show coldest cabinet temperature 

since last startup or reset 

Press 

Thermometer, display show cold excursion while button is 

pressed. 

Warm excursion

Show warmest cabinet temperature 

since last startup or reset 

Press 

Thermometer, display show warm excursion while button is 

pressed. 

Mute

Silence audible alarm

Press 

Scan

Thermometer, display show cabinet temperature, alarm icon 

continues to flash. 

Reset

Return to default display after 

excursion or alarm condition

Press  

and 

 

simultaneously, hold 

for five seconds

Excursion values are reset; thermometer, display show cabinet 

temperature. Display blinks to confirm reset.

Alarm test

Test by simulating warm and cold 

alarm conditions; key switch must be 

in alarm mode

Press  

and 

Scan 

simultaneously, hold 

for five seconds

Display and thermometer show simulated cabinet temperature, 

alarms flash and sound as appropriate. Alarms clear when test is 

completed.

Function

Programming Sequence

Adjust cold alarm setpoint

Enter programming mode by pressing 

Scan 

and holding for 5 seconds. On release, the current cold alarm 

setpoint value flashes in the temperature display; use 

 and 

 to adjust it. The display automatically returns 

to normal operating mode 30 seconds after the last key entry or after scrolling through all available functions 

and parameters.

Adjust warm alarm setpoint

Enter programming mode and press 

Scan 

repeatedly. The current warm alarm setpoint value then flashes in 

the temperature display; use 

 and 

 to adjust it. The display automatically returns to normal operating 

mode 30 seconds after the last key entry or after scrolling through all available functions and parameters. 

Parameter

Display

Notes

1. Offset

Value

Center air temperature calibration. Default value is 0 (maximum + or - 

2.9).

2. Cut On

Cut (2 sec.); On (2 sec.); then value

Cabinet temperature at which compressor starts to cool down to 

setpoint. Default value is 6ºC.

3. Differential

dIF (2 sec.); then value

Cut on – differential = temperature at which compressor stops after 

achieving cabinet temperature setpoint. Default value is 3.

4. Defrost Interval

dEF (2 sec.); Int (2 sec.); then value

Range 1 to 12 hours; default value is 01.

5. Defrost Duration

dEF (2 sec.); dur (2 sec.); then value

Range 5 to 30 minutes; default value is 15.

6. Defrost HIgh-tempTermination

dEF (2 sec.); HI (2 sec.); then value

Temperature at evaporator at which defrost cycle terminates; default 

value is 4ºC.

7. Short Cycle Delay

SHO (2 sec.); Cyc (2 sec.); then value

Range 0 to 15 minutes; default value is 0.

8. Control Probe Temperature

Cnt (2 sec.); Prb (2 sec.); then value

Display only.

9. Network address

nEt (2 sec.); Adrt (2 sec.); then value

Can only be modified by RS-485 communications software.

10.Defrost Probe Temperature

dEF (2 sec.); Prb (2 sec.); then value

Display only.

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