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
IncorrectCorrect
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.