Hitachi S1 Series Basic Manual page 168

S1 series standard inverter
7.6.3 Overvoltage
Check the load and adjust
7.6.4 Undervoltage
Overvoltage fault
Whether the voltage of the power
supply is within the standard range?
Yes
Whether UVW on the output
side ofn the inverter is short to
ground?
Whether the wiring on the
output side of the inverter is
performed properly?
Yes
Whether the ACC/DEC
time is too short?
No
Yes
Whether the loaded motor
is drived reversely?
No
If it is an inverter fault,
contact our company
Undervoltage fault
Whether the voltage of the
power supply is within the
standard range?
No
Whether the air switch and
contactor are opened or
encounter exceptions?
No
Whether a large-power device
is running on the grid that pulls
down the voltage of the grid?
No
Whether the inverter is
powered off during
running?
No
If it is an inverter fault,
contact our company
No
Ensure the power supply
meets the requirement
Yes Rectify the short-circuit
fault and perform the
wiring properly
Yes
Whether the ACC/DEC time
can be prolonged?
No
Whether to use a
brake accessory?
No
Adjust the brake
accessories and
resistance
Yes
Ensure the power supply
meet the requirement
Close the air switch and
Yes
contactor; and rectify the
exceptions
Yes
Adjust the input of the
Identify the power-off
Yes
causes, and rectify the
exceptions
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Yes
Prolong the ACC/DEC
time
Yes
Add brake accessories
grid