theColonel26
Lifetime Supporting Member
I just had a problem dumped on me.
We have been selling Machines with a Allen Bradley 22F-V2P5N103 4M 125VAC 1/2HP VFD.
A problem we had in the past was customer plugging them in to GFCI receptacles and the drives kicking the GFCI out right at the moment the motor comes to a stop.
So our Mechanical Engineer that usually deals with the products found a model of GFCI that seemed to fix the problem (LEVITON GFRBF-W). He also installed one of those GFCIs in the shop so the guys could test each machine before it went out. To solve the problem we just sold that GFCI to anyone that need to use a GFCI outlet.
I think the shop's testing was performed rather inconsistently... but that is a topic for another time.....
BUT NOW it seems that either Leviton or Allen Bradley has changed something and now the VFDs are even tripping this Leviton GFCI.
Things our MechE has tried
They are using a Shielded cable on the VFD output. My first thought is, DON'T do that, because then you are inducing current in to the shield and it is draining through the ground and causing an imbalance. Anyone have thoughts on that?
Any one have any idea's?
We have been selling Machines with a Allen Bradley 22F-V2P5N103 4M 125VAC 1/2HP VFD.
A problem we had in the past was customer plugging them in to GFCI receptacles and the drives kicking the GFCI out right at the moment the motor comes to a stop.
So our Mechanical Engineer that usually deals with the products found a model of GFCI that seemed to fix the problem (LEVITON GFRBF-W). He also installed one of those GFCIs in the shop so the guys could test each machine before it went out. To solve the problem we just sold that GFCI to anyone that need to use a GFCI outlet.
I think the shop's testing was performed rather inconsistently... but that is a topic for another time.....
BUT NOW it seems that either Leviton or Allen Bradley has changed something and now the VFDs are even tripping this Leviton GFCI.
Things our MechE has tried
- A line reactor on the input side of the VFD, which made the GFCI trip sooner in the slow down step. Before it was tripping right when it came to a stop.
- Adjusting the carrier frequency all the way to the lowest and highest setting.
- A EMI Cap Filter, which I assumed before he even tried it would make the issue worse. I was correct. As soon as the machine was plug in the GFCI tripped. Didn't even need to run it. (again because it was draining to ground which is the problem)
They are using a Shielded cable on the VFD output. My first thought is, DON'T do that, because then you are inducing current in to the shield and it is draining through the ground and causing an imbalance. Anyone have thoughts on that?
Any one have any idea's?