Preheating Operation (Quick Warming Function) - Daikin E Series Service Manual

SiBE04-624
3.2

Preheating Operation (Quick Warming Function)

Outline Operate the inverter in the open phase operation with the conditions including the preheating
command from the discharge pipe temperature.
Detail On condition
The preheating operation starts when the discharge pipe temperature drops below 10°C. At that
time, the inverter in open phase operation starts. This means that a small current is send
through one of the compressor windings in order to heat up the inside of the compressor. This is
done in order to prevent liquid compression at start up of the compressor when the outdoor
temperature is low.
OFF condition
When the discharge temperature is higher than 12°C, the inverter in open phase operation
stops.
This function is applicable for cooling only as for heat pump units.
The inverter in open phase control consumes approximately 25~40W.
Note When the preheating operation is active, there is the possibility that a frequency noise can be
noticed at the outdoor unit site due to the open phase control.
outdoor temperature ≥ 7°C
outdoor temperature < 7°C
Function and Control
Discharge pipe temperature
10˚C
Discharge pipe temperature
20˚C
Preheating OFF
12˚C
Preheating ON
Preheating OFF
22˚C
Preheating ON
Control Specification
(R5922)
(R5923)
63