Liebert 50 & 60Hz User Manual

To modify the two custom alarm messages select “CUSTOM TEXT”. Then select “Custom Text #1,” 

“Custom Text #2” or “Custom Text #3.” Text can be up to 16 characters in length and can be either a 

blank space or any of the following alphanumeric characters and symbols:

• A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z
• #,%,*,-
• 0,1,2,3,4,5,6,7,8 or 9

Use the UP/DOWN arrows to select a character, then press ENTER. The cursor will move to the 

next space where you may once use the UP/DOWN arrows to select another character, etc. The cus-

tom text alarm will be displayed only if the alarm is selected in Custom Alarms.

The level of contrast due to the viewing angle of the LCD display can be adjusted using a potentiome-

ter screw, inside the wall box next to the display.

All critical information is stored in nonvolatile memory. Setpoints and setup parameters are kept 

inside the microcontroller in EEPROM.

Equipment options are selected and enabled using DIP switches 1 through 7. These are located on the 

control board near TB3. These switches are factory set and should not require any user changes. The 

setting and function of the switches can be individually read on the LCD display.

1

Step Cool

Ramp Cool

2

Step Heat

Ramp Heat

3

Not Used

Not Used

4

No GLYCOOL

GLYCOOL

5

Disable 1 stage CW

Enable 1 stage CW

6

Not used

Not used

7

1-stage 

dehumidification

2-stage 

dehumidification

8

Disable SCR Reheat

Enable SCR Reheat

1

Beeper Disable

Beeper Enable

2

Not Used

Not Used

3

Not Used

Not Used

4

Enable Reheat

Disable Reheat

5

Enable Hum.

Disable Hum.

6

Enable Dehum.

Disable Dehum.

7

Disable Setback

Enable Setback

8

Enable Password

Disable Password