Startup Control - Midea MV5-X252W/V2GN1 Service Manual

V5 X VRF 50/60Hz

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
Four-way valve
Solenoid valve (liquid refrigerant injection)
Solenoid valve (oil balance)
Solenoid valve (fast defrosting)
Solenoid valve (EXV bypass)
Solenoid valve (indoor units bypass)
Notes:
1. Refer to Table 3-5.3 in Part 3, 5.6 "Outdoor Fan Control" for more information on fan speed steps.
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 B
Four-way valve
Solenoid valve (liquid refrigerant injection)
Solenoid valve (oil balance)
Solenoid valve (fast defrosting)
Solenoid valve (EXV bypass)
Solenoid valve (indoor units bypass)
Notes:
1. Refer to Table 3-5.3 in Part 3, 5.6 "Outdoor Fan Control" for more information on fan speed steps.
24
Wiring
8-12HP 14-22HP
diagram label
COMP(INV)
●
COMP(INV1)
FANA
●
FANB
EXVA
●
EXVB
ST1
●
SV2
●
SV4
●
SV5
●
SV6
●
SV7
●
Wiring
8-12HP 14-22HP
diagram label
COMP(INV)
●
COMP(INV1)
FANA
●
FANB
EXVA
●
EXVB
ST1
●
SV2
●
SV4
●
SV5
●
SV6
●
SV7
●
Control functions and states
Controlled according to load requirement, operating
●
frequency increased by 1 step / sec
●
1
Fan speed controlled according to discharge
●
pressure (P ):
c

At initial speed for 90 seconds.

Subsequently, P
c

P ≥ 2.7MPa => 1 step increase.
c
●

P ≤ 2.1MPa => 1 step decrease.
c
Position (steps) from 0 (fully closed) to 480 (fully
●
open), controlled
●
temperature
Off
●
Off
●
Closed for 200 secs, open for 600 secs, then closed
●
Off
●
Open for 20 mins, then closed
●
Off
●
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
temperature and load requirement
●
Position (steps) from 0 (fully closed) to 480 (fully
●
open), controlled according to discharge superheat
●
On
●
Off
●
Closed for 200 secs, open for 600 secs, then closed
●
Off
●
Off
●
Off
●
checked every 10 seconds:
according to discharge
to outdoor ambient
201608