# VFD tripping on earth ground fault



## sparkywannabee (Jan 29, 2013)

You probably used the same set of parameters from old drive to the new drive, sometimes if the load is heavy and your acceleration time is too short, you can get a grd flt, also check your torque limit parameter. You guys sound like you know what you are doing so i don't think it is a motor wiring hookup issue.


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## JRaef (Mar 23, 2009)

Ground fault in VFDs is done by the residual current method, so it can be fooled by imbalanced current in some circumstances. Check the currents when in bypass (VFD output current is tricky to measure). 

Did you leave the 2 speed contactors in place? Or are you using them now for the bypass? Might be in the contacts just not making good contact. If the currents are balanced in bypass, try swapping the conductors to the other contactor and checking them again.


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## beardie (Sep 12, 2013)

If the runs not to long can you run a temporary feed from the drive to the motor and run it up


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