Trane TKD User Manual

14 RT-SVX42B-E4
Operation
Defrost pressure switch (PHE version)
In winter mode, frost occurs in the return air side of the exchanger increasing pressure drop.
The defrost pressure switch setting should be setup so that it does not switch in free cooling
mode (100% exhaust air flow).
During the free cooling test mode, adjust the pressure switch setting to reach the threshold
point. This value of pressure drop is the maximum non frosted pressure drop. Increase this
setting by +50% to set up the frosted pressure drop.
ERM defrost mode is active when the timer relay light is activated.
The defrost pressure switch activates a timer relay that opens the bypass damper for a
duration of 5 minutes (default setting).
During defrost operation, the mixing damper stays in the minimum position.
Figure 13 - Air circulation in defrost operation
PHE
125-155-175-200-250-265-290-340
PHE
275-300-350-400-500-600
100%
Min%
By-pass
Min%
Min%
Min%
Min%
Min%
Min%
0%
By-pass
100%
Min%
Min%
Defrost operation

Trane TKD Specifications

General

Brand	Trane
Model	TKD
Category	Heating System
Language	English