Daikin DPS - Heat Pump Control; Heat Pump Defrost Operation

Heat Pump Control
A heat pump unit transitions between the Cooling, MinDAT and
Heating operating states as described above. If compressor
heating is available it is used rst to provide the heating source
during the MinDAT and Heating states. If compressor heating
is unavailable (as during defrost operation for example) or
inadequate to meet the heating requirements during these
states, supplemental heating will be used to add to or in lieu of
the compressor heating.
When dehumidication operation is active, the compressors
will operate in the cooling mode and the reheat will be provided
by either hot gas reheat or by the supplemental heat in the
unit depending on the conguration parameter setting. When
a unit is congured for heat pump operation compressor
heating will always be dened as the “primary” heating and the
supplemental heating or hot gas reheat (whichever is currently
active) is dened as the “secondary” heat source.
Heat Pump Cooling Operation
When the unit transitions from the Fan Only to Cooling
operating state or if dehumidication operation becomes
active while in the Fan Only state, compressor cooling
operation begins. Refer to Inverter Compressor Cooling State
Descriptions for a detail description of the cooling compressor
operating sequence.
Heat Pump Heating Operation
When the unit transitions from the Fan Only to MinDAT
(page 109) or Heating operating state, compressor heating
operation begins. Refer to Inverter Compressor Heating
Operation State (page 118) for a detail description of the
heating compressor operating sequence.
Heat Pump Defrost Operation
Defrost operation is required when compressor operation is in
the Normal Heating state when frost build up on the outdoor
coil interferes with the normal heat transfer from the outdoor
coil to the ambient air. Refer to Defrost Operation– Heat Pump
Units Only for a detailed description.
operator’s guIde
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