DC INVERTER U-MATCH AIR CONDITION                                       MAINTENANCE 
 
121
Tripping◆  
 
Tripping 
If the switching
capacity can meet
the requirements?
 
Tripped once 
energized
 
Tripped when 
the compressor 
is started?
Install the electric 
switch according to the 
capacity requirements 
as specified in 
operating instructions.
Check PFC board. Cut off the
power for 1 minute or reduce
the busbar voltage to 36V o
lower. Then, remove the
connection cable on PFC board
and use multimeter to measure 
if P-N, or P-L1_2, or L1_2-N on 
PFC board is short circuited. 
Leakage curren
 
is too high. 
Please check fo
 
replace the filter.
 
Short circuited? 
The PFC module is damaged.
Replace the PFC module and check
if AC contactor is stuck. Meanwhile,
ensure that P-N is short circuited.
The possible reasons causing this
trouble include: 
 The screws fixing 
the module are not correctl
tightened;   The AC contactor on
C side in parallel to the recharging
resistor is stuck, and the transien
 
recharging current upon
energization is too high; 
 The input 
voltage is too low; or 
 The cable 
connection is wrong.   
Check driver board. Cut off the 
power for 1 minute or reduce 
the busbar voltage to 36V o
 
lower. Then, remove the 
connection cable on drive
 
board and use multimeter to 
measure if P-N, or P-U, or P-V, 
or P-W, or U-N, or V-N, or W-N 
on driver board is short 
circuited.  
Short circuited?
If the fron
C contactor is
stuck?
 
If the insulation
on PFC inducto
winding is
damaged? 
The system is 
abnormal. Please chec
 
connections or winding 
for short circuiting o
 
other troubles.
 
The AC contacto
 
is damaged. 
Please replace 
with a same type 
of contactor. 
Replace PFC 
inductor
 
Check if the 
cable 
connection is 
wron
Record and 
feed back 
Leakage curren
 
is too high. 
Please check fo
 
replace the filter.
PFC ON?
No 
Yes
Yes
Yes 
Yes
Yes
Yes 
Yes 
No
No
No 
Yes
No
No
No 
The IPM module is damaged. 
Replace the driver board. The 
possible reasons causing this 
trouble include: 
 The screws 
fixing the module are no
 
correctly tightened; 
  The 
load is severely overloaded; o
 
 The interference causes 
short circuiting inside IPM 
module.  
No