If the inverter has 
not started, the 
UPS has no output, 
and inverter 
startup is not 
allowed.
If the inverter has 
started, inverter 
operation is not 
affected, but 
transfer to bypass 
mode is not 
allowed.
Possible cause: The bypass input cable 
connections do not match the output 
system.
Measure: Ensure that the bypass input 
cable connections match the output 
system.
The power supply 
from the UPS and 
system is not 
affected.
Possible cause: The fan is abnormal.
Measure: Clean off the foreign objects 
around the fan. If the alarm persists, 
contact 
Huawei technical support for 
The UPS shuts 
down.
The UPS may 
transfer to 
another working 
mode or shut 
down.
Possible cause: The inverter output is 
short
Measure: Rectify output port short 
circuits, 
restart the UPS. 
If the alarm persists, contact 
technical support for repair.
If the bypass is 
abnormal, the 
UPS may power 
off.
The inverter is not started.
• The load exceeds the rated inverter 
Check whether other alarms are 
generated. If yes, see the other 
handling methods.
If no, start the UPS manually.
The UPS may 
power off if 
batteries are 
abnormal.
The mains input is abnormal.
The UPS is in battery self-check 
state.
The mains loading capability is 
insufficient.
Measures:
• Check the mains input. If the mains 
input is abnormal, wait until the 
mains input recovers.
Check whether the UPS is in 
battery self-check state.
• Reduce the load or replace the UPS 
with a larger-capacity UPS.
The power supply 
from the UPS and 
system is not 
affected.
Batteries are not connected.
Batteries are not securely 
connected.
Check that batteries are securely 
connected.