Sinclair ASC-18A, Service Manual

Page: 122 / 264

DC INVERTER U-MATCH AIR CONDITION MAINTENANCE
116
IPM module protection ◆
E5 displayed on
wired controller
(overcurrent
protection)
Monitor display
Mainboard indicator
IPM protection
Bright Bright
Bright Blink Blink
Bright
Cut off the power for 1 minute
or reduce the busbar voltage to
36V or lower. Then, switch on
the power again and start the
machine to run a period of time.
After that, check if the fault
disappears.
Wrong judgment caused by
interference. Please check if
there is source of interference
around or if the cabling inside the
electric box is correct
If the compressor is
started and running?
I. Use the monitor software to check if the DC busbar
voltage is normal. The normal voltage is 380±10V. If
not, please check PFC board and its connection
cable for any error.
II. If the DC busbar voltage is normal, please cut off
the power for 1 minute and then check as follows:
1. Check if the screws fixing the IPM module are
properly tightened. If not, it will cause module
overtemperature or IPM protection.
2. If the screws fixing the IPM module are correctly
tightened, please check if +15V voltage at CN11 pin
on power board is stable. If lower than 13.5V, it can
be judged that the power board is failed. In this case,
please replace the power board.
3. If the above problems have been eliminated,
please check if the outdoor unit is in good ventilation.
Under cooling mode, outdoor temperature too high
may cause poor radiation to IPM module and thus
result in protection.
4. Check if the radiator is dirty or blocked. If dirty or
blocked, it may cause poor radiation to the module
and thus result in protection.
Cut off the power for 1 minute and then check
according to the procedures below:
1. Measure if IPM module is damaged. Method:
Remove UVW wires on compressor and use the
multimeter to measure the resistance U-N, V-N, W-N,
P-U, P-V and P-W on driver board. It is normal if over
1M Ω . If not, it indicates that the module is damaged,
in which case it is needed to replace the driver board.
2. If the IPM module is proven normal as tested
according to Step 1, please check if the measuring
resistor RS1 ～ RS6 on driver board for any damage
like broken pin and burn marks. If any, please replace
the driver board.
3. If the IPM module is proven normal as tested
according to Step 1 and 2, please check the +15V
voltage at pin CN11 on power board (mainboard
Z81P-1, 30228104) is normal (The driver board can
work normally only if this voltage is over 13.5V). If
not, please replace the power board; or replace the
driver board.
Complete the inspection and connect the cable
correctly. Switch on the power again and start the
machine.
Yes
No
No
Yes
No
Fault eliminated?
Yes
Check if the
compressor is
normal
Record and feed back