Daikin VRV IV+ Service Manual page 146

2 | Troubleshooting
2.3.138 U1-01-05-07 – Reverse phase detection
Service manual
146
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Main error code
U1
INFORMATION
Main, Sub 1 and Sub 2 indications are relevant in multiple outdoor unit
configurations. Main outdoor unit is the unit to which F1‑F2 IN transmission line is
connected. Main, Sub 1 and Sub 2 outdoor units can be identified by field setting
1‑00.
Trigger
Main PCB detects reverse
phase between L1 - L3
phases.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check the phase sequence on the mains power supply terminal, see "To check
the power supply of the unit" in
needed.
Possible cause: Incorrect phase sequence on mains power supply terminal.
2 Check if any of the phases is missing on the mains power supply terminal, see
"To check the power supply of the unit" in
Correct if needed.
Possible cause: Missing phase(s) on mains power supply terminal.
3 Check if the phase L3 is present on the power supply connector X1A on the
main PCB, see "To perform a power check" in
if needed.
Possible cause: Missing phase L3 on main PCB power supply connector.
4 Perform a check of the fuses of the main PCB, see
Possible cause: Blown fuse(s) on main PCB.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Sub error code
01
05
07
Effect
Forced stop.
"4.1 Electrical circuit"
"3.11 Main
Unit
Main
Sub 1
Sub 2
Reset
Power reset at outdoor
unit.
4
[ 356]. Correct if
"4.1 Electrical circuit"
4
PCB" [ 290]. Correct
4
"3.11 Main PCB" [ 290].
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
4
[ 356].