Seabreeze PTAC09CH3ZX, Service Manual

Page: 5 / 15

953-0002-revC 07/06/09
PAGE 5
When in heat mode the Heat pump function operates exclusively to provide heat. If the demand for
heat is greater than the Heat Pump can supply, the electric heat strips will activate to supplement
the heat pump. The heat strips will only work between 73.4 and 78.8 ºF.
If the setpoint is within this range, when the room temperature becomes satisfied, the Electric heat
will shut off.
1.4 Overheat protection of evaporator (only applicable In heat mode)
●
This function is to prevent overheating inside the evaporator.
●
When the temperature of indoor coil rises to 142ºF, the compressor and outdoor blower
fan will stop, and two minutes later, the reversing valve is closed(heat pump models only).
The blower fan will continue to run at the set speed. When the temperature of indoor coil ≤
122ºF, it can reenter heat mode.
●
When the temperature of the indoor coil ≥ 133ºF, the outside blower fan shuts down and
the system will enter overload protection. When the coil temperature of the inside unit is ≤
125.6ºF, normal operation will resume.
1.5 Defrosting
●
The system will enter defrost under the following conditions:
①
The compressor has been running (in heat mode) for over 7 minutes.
②
The outside coil temperature
≤
-9ºF
③
Defrost time is determined by the operating time of the compressor. If the compressor
has been running for over 30 minutes and defrost is required (based on Items 1 &2 above)
defrost cycle will be over 10 minutes in length. If the compressor has been running for over
40 minutes, the defrost time will be between 7 and 10 minutes in length. If compressor has
been running for more than 50 minutes, the defrost time will be between 4 and 7 minutes
in length. If the compressor has been running for over 60 minutes, the defrost time will be
less than 4 minutes.
•
In order to determine defrost termination, one of the following conditions must be met:
①
System has been in defrost for over 10 minutes
②
Outside coil temperature > 7ºF
Room temperature