Midea VRF V4 Plus I Series User Manual

MCAC-VTSM-2014-04 R410A DC Inverter V4 Plus 50Hz
Troubleshooting 101
5.6 H6: Quantity of indoor units decrease error (Only display on master unit, all the ODU in standby)
“H7” error will display when the quantity of indoor units decrease above 3 minutes.
Note:
1. How to check whether the transformer of IDU is disabled
①
The voltage input for IDU transformer is 220V, the voltage output of is AC9V (yellow-yellow) and AC13.5V (brown-brown)
2. How to check whether the 485 communication IC is disabled
②
The normal voltage between “P” and “GND” is DC2.5~2.7V, between “Q” and “GND” is DC2.5~2.7V. If the voltage is out of the
normal range, the 485 communication IC is disabled.
*Indoor units should be unified power supply, which can prevent compressor from liquid hammer caused by dropped indoor
units with EXV unclosed.
H7: Quantity of indoor units
decrease error
Communication terminals P Q E
are loose
Fasten the communication
terminals
Yes
Transformer of IDU is disabled
①
Replace the transformer
IDU are not unified power supply*
Insure all the IDU be unified
power supply
485 communication IC is disabled
②
IDU Main board is
disabled
Replace the IDU PCB
No
No
No
No
Yes
Yes
P Q E terminals
Some IDU are assigned the
same address
Some IDU are power off
Set the IDU addresses differently
Power on all IDU
No
No
Yes
Yes

Midea VRF V4 Plus I Series Specifications

General

Brand	Midea
Model	VRF V4 Plus I Series
Category	Air Conditioner
Language	English