Liebert 50 & 60Hz User Manual

The controller time clock must be set to allow for the setback control. The clock uses the 24-hour sys-

tem (i.e., 12 midnight is entered 24:00). To change the time press ENTER to select the function, then 

use the UP/DOWN arrow to change the first character, press ENTER to store, then press the UP/

DOWN arrow key to change the character, press ENTER to store, etc. The real time clock is backed-

up.

The controller date must be set to allow for setback control. To change the date press ENTER, then 

use the UP/DOWN arrow to change the first character, press ENTER to store, press the UP/DOWN 

arrow key to change the second character, etc.

The microprocessor can be programmed for night and weekend setback. Two (2) events can be pro-

grammed for a five-day workweek and two (2) events can be programmed for a two-day weekend. The 

following table can be used to devise a setback plan.

Selecting SETUP OPERATION from the Main Menu will display the following selections:

• RESTART TIME DELAY
• C/F DEGREES
• HUMIDITY CONTROL METHOD
• LEAD COMPRESSOR
• SHOW  DIP  SWITCH
• VALVE TIME (if valve present)
• CW FLUSH (if valve present)

Use the UP/DOWN ARROW to scroll through the submenu. Press ENTER to select a particular 

function.

This function delays unit restart after main power is restored to the unit. If several systems are oper-

ating, the time delays should be set to different values to cause a sequential start. Delay can be set 

from 0.1 minutes (6 seconds to 9.9 minutes. Setting the value to zero (0) will prevent unit restart 

when power is restored. In this case, the unit must be restarted manually by pressing the ON/OFF 

button on the keypad.

Time 1
Temperature1
Sensitivity 1
Humidity 1
Humidity Sensitivity 1
Time 2
Temperature 2
Sensitivity 2
Humidity 2
Humidity Sensitivity 2