Site Preparation and Installation
2.4.3Piping Connections and Coolant Requirements Drain Line
! CAUTION
The drain line must not be trapped outside the unit, or water may
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.
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
Unit | Unit |
Continuous slope | Do not externally |
away from unit | trap the unit |
Correct | Incorrect |
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.
Incorrect
11
