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by **DigitalMCO** on Tue Jul 02, 2013 5:19 am

A while back I got a slight jolt when I touched the metal housing of what I believe to be a noise suppression filter inside my GE Type F controller.

Well I finally got around to trouble shooting the problem and discovered that the back of the panel was modified. A neutral wire ran to a mounting screw that held the suppression filter (upper left in the picture) to the back panel and then it went to the ground terminal of an AC receptacle mounted next to the filter. From there a jumper took it to the neutral (common) side of the plug. Apparently this was the cause of my electrifying experience. I made a simple wiring change and now my suppression filter housing and the ground on the outlet are no longer hot.

So my question is, why would someone tie the cabinet ground and neutral wires together? Clearly this didn't cause the breaker to trip, but still created a live ground situation inside the cabinet none the less.

http://i592.photobucket.com/albums/tt1/ ... 0_2153.jpg

by **JVC8230** on Tue Jul 02, 2013 5:57 am

A lot of older cabinets are like that. My EF-20 cabinet does not have an isolated ground from the neutral. SOunds like your hot and common got swapped though. I used to get jolts by touching my cabinet, and when I check the outlet nearby, the hot and common were wired backwards!!!! BZZZZZZ!!!!!!

by **mcha9797** on Tue Jul 02, 2013 6:07 am

I had a similar issue with my Marbelite M15 controller, there was a spiral jumper wire going from the neutral connection on the back panel to a mounting screw that clearly tied it to the cabinet. :shock:

I was told to remove it.

by **TacomaJoe** on Tue Jul 02, 2013 6:33 am

I think there is something else going on in the cabinet/wiring. Having the neutral and ground tied together in the cabinet and tied to the AC common does not present a shocking hazard. To get a shock from the case of the filter, it would need to be ungrounded. The metal case of those filters will have a shock hazard if they are not tied to neutral because of the internal capacitors. If you don't have the neutral and the ground of the cabinet bonded together, the entire cabinet will be hot. This occurs if you use a 2 wire cord to power it, or if your neutral isn't bonded at the service point.

by **coyttl** on Tue Jul 02, 2013 7:16 am

I'd have to agree with Joe - another way you'd get a shocking in that experience is if your ground/neutral wasn't really ground. i.e. It was floating above ground. :)

by **DigitalMCO** on Tue Jul 02, 2013 12:19 pm

The ground from the AC cable feeding the controller is attached to the body of the cabinet. All the ground wires from the signals go to a buss on the sidewall of the cabinet which is also installed to the AC cable ground. There is nothing from the backpanel connected to the ground as the backpanel is isolated from the metal cabinet.

Am I to assume that the neutral and the ground on the backpanel (which feed the filter and outlet) should be bonded together and attached to the incoming power cables ground that feeds the controller? Or will this just make the entire cabinet HOT?
:scratch:

by **notMUTCDcompliant** on Tue Jul 02, 2013 12:25 pm

no. No bonding. Bonding is done at one location in your house, and that is at the breaker panel.

I would remove the lightning protector. They are a major source of issues when in a house.

Keep your case ground/green

Keep your Neutral/White isolated

Hot/Black stays hot :Poof:

by **SignalLab** on Tue Jul 02, 2013 12:59 pm

coyttl wrote:I'd have to agree with Joe - another way you'd get a shocking in that experience is if your ground/neutral wasn't really ground. i.e. It was floating above ground. :)

YEP and YOU become the ground! :blink:

by **Crunge98** on Tue Jul 02, 2013 3:02 pm

What about the new code where they are not bonding them.

by **64ragtop** on Tue Jul 02, 2013 7:48 pm

This little bugger was the culprit with my Type F. I didn't have any weird neutral jumper wires like you have described, but this filter/capacitor (or whatever it's called) definitely had current potential on the case. The current was low (checked with a meter) with no load, and of course it increased when connected to a light bulb. I could FEEL it when touching the cabinet

I simply grounded my cabinet (an isolated cable going all the way back to the service panel ground spike) and that solved the problem completely.

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