Trane 4TVH0086FE000AA Service Manual page 44

4.3 Startup Control for Heating Operation
Table 3-4.2: Component control during startup in heating mode
Component
Inverter compressor A
Inverter compressor B
DC fan motor A
DC fan motor B
Electronic expansion
valve A
Electronic expansion
valve C
Four-way valve
Solenoid valve (liquid
refrigerant injection)
Solenoid valve (oil
balance)
Solenoid valve (fast
defrosting (in heating)
and unloading (in
cooling))
Solenoid valve (EXV
bypass)
Solenoid valve (indoor
units bypass)
Solenoid valve (inverter
compressor A vapor
injection)
Solenoid valve (inverter
compressor B vapor
injection)
Solenoid valve (inverter
compressor B pressure
balance)
Wiring
diagram 8-12HP 14-18HP
label
COMP(A)
● ●
COMP(B)
FANA
● ●
FANB
EXVA
● ●
EXVC
● ●
ST1
● ●
SV2
SV4
● ●
SV5
● ●
SV6
● ●
SV7
●
SV8A
● ●
SV8B
SV9
20-24HP 26-28HP 30-32HP
● ● ●
● ● ●
● ● ●
● ● ●
● ● ●
● ●
● ● ●
●
● ● ●
● ● ●
● ● ●
●
● ●
● ●
● ● ●
43
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
Position (steps) from 0 (fully closed) to 480
or 3000 (fully open), controlled according
to discharge superheat
Position (steps) from 0 (fully closed) to 480
(fully open), controlled according to
temperature different between plate heat
exchanger inlet and outlet
On
Off
Closed for 200 secs, open for 600 secs, then
closed
Open for 4 mins, then closed
Off
Controlled according to load requirement
Controlled according
compressor A
Controlled according
compressor B
Open before compressor B startup
to inverter
to inverter