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Challenge #453 ·
vfds
VFD Trips the Instant It Starts
A VFD (U1) on a sump pump trips the instant it tries to start. The keypad locks out with a fault every attempt. Read it, then make the call.
Read the fault code
F004
Output Ground Fault
VFD keypad (U1)
A.
The output stage is shorting, so swap the VFD (U1) for a fresh unit
B.
A motor lead or winding is leaking to earth, so output current escapes to ground
C.
The accel ramp is set too fast, surging current as it tries to start
D.
Input line voltage is too low to hold the bus on start
Explain your reasoning
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