V6-i VRF 50/60Hz
36
Midea
V6
-i
Series S
er
vice M
anual
4
Startup Control
4.1
Compressor Startup Delay Control
In initial startup control, compressor startup is delayed for 12 minutes in order to let the outdoor unit search for the indoor
units’ addresses. In restart control (except in oil return operation and defrosting operation), compressor startup is delayed
such that a minimum of 7 minutes has elapsed since the compressor stopped, in order to prevent frequent compressor
on/off and to equalize the pressure within the refrigerant system.
4.2
Startup Control for Cooling Operation
Table 3-4.1: Component control during startup in cooling mode
Component
Wiring
diagram
label
8-12HP 14-18HP 20-24HP 26-28HP 30-32HP
Control functions and states
Inverter compressor A
COMP(A)
●
●
●
●
●
Controlled according to load requirement,
operating frequency increased by 1 step / sec
Inverter compressor B
COMP(B)
●
●
●
DC fan motor A
FANA
●
●
●
●
●
Fan speed
1
controlled according to discharge
pressure (P
c
):
At initial speed for 90 seconds.
Subsequently, P
c
checked every 10
seconds:
P
c
≥ 2.7MPa => 1 step increase.
P
c
≤ 2.1MPa => 1 step decrease.
DC fan motor B
FANB
●
●
●
Electronic
expansion
valve A
EXVA
●
●
●
●
●
Position (steps) from 0 (fully closed) to 480 or
3000 (fully open), controlled according to
discharge temperature
Electronic
expansion
valve C
EXVC
●
●
●
●
●
Position (steps) from 0 (fully closed) to 480
(fully
open),
controlled
according
to
temperature different between plate heat
exchanger inlet and outlet
Four-way valve
ST1
●
●
●
●
●
Off
Solenoid
valve
(oil
balance)
SV4
●
●
●
●
●
Closed for 200 secs, open for 600 secs, then
closed
Solenoid valve (fast
defrosting (in cooling)
and
unloading
(in
heating))
SV5
●
●
●
●
●
Open for 4 mins, then closed
Solenoid valve (EXV
bypass)
SV6
●
●
●
●
●
Open for 10 mins, then controlled according
to pressure
Solenoid valve (indoor
units bypass)
SV7
●
●
Controlled according to load requirement
Solenoid
valve
(inverter compressor A
vapor injection)
SV8A
●
●
●
●
Controlled according to inverter compressor
A
Solenoid
valve
(inverter compressor B
vapor injection)
SV8B
●
●
Controlled according to inverter compressor
B
Solenoid
valve
(inverter compressor B
pressure balance)
SV9
●
●
●
Open before compressor B startup
Notes:
1.
Refer to Table 3-5.3 in Part 3, 5.6 “Outdoor Fan Control” for more information on fan speed steps.
