Table of Contents
Advertisement
V8 VRF Indoor Units
Troubleshooting
Note:
1. If you measure the resistance between terminal blocks M1 and M2 of the IDU main control board,
normally this resistance is greater than 1 MΩ.
2. Figure 1 shows the schematic diagram of MDV-Link communication line connection. The connection of
repeater wires must comply with the following requirements. Otherwise, an IDU communication fault may
occur.
62
If the indoor and outdoor units communicate via MDV-Link (M1M2):
C21 (6)
If the indoor and outdoor units
communicate via MDV-Link
(M1M2)
Figure 1 Schematic diagram of MDV-Link communication cable connection
Upstream IDU and ODU of repeater 1# (including master ODU)
Repeater 1#
IDU 11#
Downstream IDUs
of repeater 1#
Upstream IDUs
of repeater 2#
Cause 1: M1/M2 cable short-
circuits or cuts off (1)
Cause 2: The repeater UP and
DOWN ports are not
connected to the
corresponding indoor unit (2)
Cause 3: The power supply of
repeater is cut off
Cause 4: Communication
cables of the repeater, ODU,
and IDU have formed a closed
loop (3)
Cause 5: M1 and M2 of IDU
have been connected to a
matching resistor (4)
Cause 6: MDV-Link is not
enabled for ODU (5)
Cause 7: Different
communication networks
(M1M2, PQE, X1X2) are
connected
Cause 8: The IDU main control
board or ODU main control
board is damaged
Master ODU
IDU 10#
IDU 1#
Repeater 2#
IDU 20#
IDU 21#
Downstream IDUs of repeater 2#
Properly connect the
cable
Properly connect the
cable
Check the power supply
of the repeater and
restore the power
supply
Properly connect the
cable
Remove the matching
resistor
Read the ODU
Installation Manual and
enable MDV-Link
Connect the
communication cable to
the right port based on
the type of the
communication network
Replace the damaged
main control board
IDU 30#
Advertisement
Table of Contents
