V6-i VRF 50/60Hz
37
4.3 Startup Control for Heating Operation
Table 3-4.2: Component control during startup in heating mode
Control functions and states
Controlled according to load requirement,
operating frequency increased by 1 step /
sec
Open once the four-way valve has opened,
controlled according to outdoor ambient
temperature and load requirement
Electronic expansion
valve A
Position (steps) from 0 (fully closed) to 480
or 3000 (fully open), controlled according
to discharge superheat
Electronic expansion
valve C
Position (steps) from 0 (fully closed) to 480
(fully open), controlled according to
temperature different between plate heat
exchanger inlet and outlet
Solenoid valve (oil
balance)
Closed for 200 secs, open for 600 secs, then
closed
Solenoid valve (fast
defrosting (in cooling)
and unloading (in
heating))
Open for 4 mins, then closed
Solenoid valve (EXV
bypass)
Solenoid valve (indoor
units bypass)
Controlled according to load requirement
Solenoid valve (inverter
compressor A vapor
injection)
Controlled according to inverter
compressor A
Solenoid valve (inverter
compressor B vapor
injection)
Controlled according to inverter
compressor B
Solenoid valve (inverter
compressor B pressure
balance)
Open before compressor B startup