Liebert 50 & 60Hz User Manual

Page of 72
Site Preparation and Installation
11
2.4.3 Piping Connections and Coolant Requirements
Drain Line
A 3/4 in. (19.1 mm) female pipe thread (FPT) connection is provided for the evaporator coil condensate 
drain. This line also drains the humidifier, if applicable. The drain line must be located so it will not 
be exposed to freezing temperatures. The drain should be the full size of the drain connection. 
The evaporator drain pan includes a float switch to prevent unit operation if drain becomes blocked.
Figure 6
Drain installation
!
CAUTION
The drain line must not be trapped outside the unit, or water may back-up in drain pan. 
Drain is internally trapped.
This line may contain boiling water. Use copper or other suitable material for the drain line. 
Sagging condensate drain lines may inadvertently create an external trap.
Incorrect
Incorrect
Correct
Unit
Unit
Unit
Continuous slope 
away from unit
Do not externally 
trap the unit
These are external traps also, although 
unintentional. Lines must be rigid 
enough to not bow between supports. 
Humidifier drain water can approach
100° Celsius.