Startup Control - Midea V6 Series Service Manual

V6 VRF 50Hz

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 master 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
Inverter compressor A
Inverter compressor B
DC fan motor A
DC fan motor B
Electronic expansion valve
A
Electronic expansion valve
B
Electronic expansion valve
C
Four-way valve
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)
Notes:
1. Refer to Table 3-5.3 in Part 3, 5.6 "Outdoor Fan Control" for more information on fan speed steps.
36
Wiring
diagram 8-12HP 14-16HP
label
COMP(A)
● ●
COMP(B)
FANA
● ●
FANB
EXVA
● ●
EXVB
●
EXVC
● ●
ST1
● ●
SV4
● ●
SV5
● ●
SV6
● ●
SV7
●
SV8A
● ●
SV8B
SV9
18-28HP 30-32HP
Controlled according to load requirement, operating
● ●
frequency increased by 1 step / sec
● ●
Fan speed
● ●
pressure (P

At initial speed for 90 seconds.

Subsequently, P
● ●
● ●
Position (steps) from 0 (fully closed) to 480 (fully
open), controlled according to discharge temperature
● ●
Position (steps) from 0 (fully closed) to 480 (fully
open), controlled according to temperature different
● ●
between plate heat exchanger inlet and outlet
Off
● ●
Closed for 200 secs, open for 600 secs, then closed
● ●
Open for 4 mins, then closed
● ●
Open for 10 mins, then controlled according to
● ●
pressure
Controlled according to load requirement
●
Controlled according to inverter compressor A
● ●
Controlled according to inverter compressor B
● ●
Open before compressor B startup
● ●
Control functions and states
1
controlled according to discharge
):
c
checked every 10 seconds:
c

P ≥ 2.7MPa => 1 step increase.
c

P ≤ 2.1MPa => 1 step decrease.
c