New home not properly grounded.

[Phelpstx]

Hello I’m a retired electrician and just bought a new home in the spring. Where we live we have a lot of new construction going on and have had a couple common surges here and there where we have to reset breakers. Here recently I noticed something unusual going on with our electric. We have a double oven in our kitchen and every time we would turn on the lower oven it would trip our garage gfci. The garage gfci 15 amp single pole and double oven 40 amp two pole are not connected in anyway.

The double oven has been checked by the manufacturer and appears to be fine.

After inspecting our main disconnect I determined the main bonding jumper from our main disconnect to our electrical panel was never installed by the builders electrician and the city inspector overlooked it. The only ground wires that our Main panel had was the gas bond, low voltage bond, plastic water ( no bond ) with no bonding jumper to the first means to disconnect.

I installed the bonding jumper from our main panel to our main disconnect which has our ground to the electrode, u/f ground, and now bonding jumper to the main panel.

As far as I can tell it does not appear that the home has no other damage due to not being properly grounded for a year. Is there any additional testing you would do to check the wiring inside the walls?

Anyone have a better explanation other than just not having a ground on why the garage gfci, afci would trip, and surge protectors go bad while using the double oven?

Thanks

 

[letgomywago]

Do you have pictures. Remember afci will trip from adjacent circuits in the panel. That garage 1 pole 15 should be the lighting and is probably afci. The 40 amp is it a gfci breaker becuse of being close to a sink then there's a few issues there since hardwire wouldn't require gfci. If the 40 amp is tripping also there's something wierd there since I've never seen an oven in normal use trip anything without something else going on.

 

[Phelpstx]

I should note that our panel is a square d qo. The garage gfci is on a single pole 20 amp breaker, the double oven is on a double pole 40 amp breaker, and the game room is on a 15 amp AFCI this was the circuit that had the surge protectors that went bad while we were using the lower oven. The oven is not near water and not on a gfci breaker.

Our garage gfci would trip out as soon as we turned on the lower oven at the double oven. As soon as we turned the oven off at the double oven I was able to reset this gfci in the garage. This was all done before we realized that we were missing the main bonding jumper in our electrical panel.

 

[ptonsparky]

Yes, pictures of your main panel and your main disconnect. Interiors.

 

[ptonsparky]

Are you saying there was no Equipment Grounding Conductor to your panel from the Main Disconnect?
Or a System Bonding Jumper was never installed at the Main Disconnect?
I am guessing the main disconnect is remote from a main lug only panel

 

[Sea Nile]

I installed the bonding jumper from our main panel to our main disconnect which has our ground to the electrode, u/f ground, and now bonding jumper to the main panel.

It's hard for me to visualize what you are saying, but this is my best guess.

Are you saying that you installed the bonding jumper at your main panel, which has your first disconnect. Which is also where the grounding electrode conductor lands, and where the neutral of your 3 wire service lateral lands, because you don't have an outside disconnect?

 

[Phelpstx]

Attached is a picture of our main disconnect, electric panel, and panel index

- The bonding jumper from main disconnect to the electrical panel is new. Previously when I was experiencing issues with our electric there was no bonding jumper installed between the main disconnect, and electric panel.

- all terminations in meter base, main disconnect, and panel have been properly torqued with no indication of any loose connections

- all grounds in main panel have been isolated.

- 40 amp oven breaker has never tripped while using oven, 20 amp garage gfci breaker has never tripped but the garage gfci was tripping only when we would use our oven, 15 amp afci for media room tripped while using the oven once blowing out two surge protectors

 

[Sea Nile]

Oh wow, so correct me if I'm wrong, but you didn't have an effective ground fault return path until you bonded the main panel to the outside panel.

 

[Phelpstx]

It's hard for me to visualize what you are saying, but this is my best guess.

Are you saying that you installed the bonding jumper at your main panel, which has your first disconnect. Which is also where the grounding electrode conductor lands, and where the neutral of your 3 wire service lateral lands, because you don't have an outside disconnect?

Sorry the the confusion. I’ve got a outside main disconnect and a main lug panel in our garage.

Outside Disconnect :
Has one #4 bare copper for u/f ground
Has one #6 bare copper for ground electrode

Main Lug Panel :
Has one #6 bare copper to bond gas meter outside
Has one #6 bare copper to bond low voltage outside

I installed a #6 bare copper bonding wire from our main lug panel to our main disconnect.

Oh wow, so correct me if I'm wrong, but you didn't have an effective ground fault return path until you bonded the main panel to the outside panel.

Correct. Our main lug panel was never bonded to our outside disconnect.

The builder, electrician, and city inspector missed it. It was blowing my mind how our garage gfci would trip every time we turned on our lower oven. My guess was because we didn’t have an effective grounding path it was somehow feeding back through the garage gfci causing it to trip.

 

[ptonsparky]

I doubt the lack of an EG conductor is/was the issue.
I see other issue with the installation, but none that I see would be a flag for the troubles you describe.

 

[tortuga]

I think all you added was a wire type equipment ground, if it is metal nipple between the panels that was your equipment ground.
Your service is outside, you have a 200A feeder to your garage panel.
I would have put all those bonding wires on the neutral bar of the outside service disconnect instead of relying on the enclosure as a conductor.
Also I can't tell but it looks like you might be missing a bushing on the nipple.

 

[hillbilly1]

I would have put the spd outside. Is this tract housing? I would bet a bunch of them are like that. Those contractors do cookie cutter jobs with unqualified help.

 

[hillbilly1]

I think all you added was a wire type equipment ground, if it is metal nipple between the panels that was your equipment ground.
Your service is outside, you have a 200A feeder to your garage panel.
I would have put all those bonding wires on the neutral bar of the outside service disconnect instead of relying on the enclosure as a conductor.
Also I can't tell but it looks like you might be missing a bushing on the nipple.

Best I can tell from the picture, looks like pvc.

 

[Phelpstx]

I doubt the lack of an EG conductor is/was the issue.
I see other issue with the installation, but none that I see would be a flag for the troubles you describe.

At this point I’m really starting to think that maybe our double oven had an internal fault which was causing interference issues that was causing the gfci to trip somehow. Oddly enough the oven breaker never tripped.

We had the appliance guy come check the double oven. I showed him that it was causing our garage gfci to trip. We shut the breaker off to the double oven. He examined it and said everything looked good connection wise inside the oven. After he installed the oven back in the cabinet we turned the bottom oven on and the gfci in the garage gfci stopped tripping.

I questioned that maybe the whip for the oven was maybe making some connection between a ground and neutral that may have caused that gfci to trip. Obviously it was not shorting out because if it was the breaker would have tripped for the oven.

Earlier in the week we did experience a power surge. Would it be possible that maybe this caused the oven to fault somehow and shutting the breaker off to the oven and turning it back on reset itself to where it wouldn’t cause the garage gfci to trip.

Thanks

 

[hillbilly1]

I have experienced arc faults ahead of the breakers can cause problems. The poco had a bad connection at the pole mounted transformer that was arcing. I would have 4-5 arcfault breakers randomly trip, but within seconds of each other. My wife leaves out early in the morning, and said there was a red light on at the transformer………connection was glowing. You may have had an arcing fault on the oven that the was picked up as an arcfault on the other breaker.

 

[Phelpstx]

I think all you added was a wire type equipment ground, if it is metal nipple between the panels that was your equipment ground.
Your service is outside, you have a 200A feeder to your garage panel.
I would have put all those bonding wires on the neutral bar of the outside service disconnect instead of relying on the enclosure as a conductor.
Also I can't tell but it looks like you might be missing a bushing on the nipple.

I agree on relocating the bonding wires instead of relying on the enclosure. Yeah they did not put the bushing on.

 

[Phelpstx]

I have experienced arc faults ahead of the breakers can cause problems. The poco had a bad connection at the pole mounted transformer that was arcing. I would have 4-5 arcfault breakers randomly trip, but within seconds of each other. My wife leaves out early in the morning, and said there was a red light on at the transformer………connection was glowing. You may have had an arcing fault on the oven that the was picked up as an arcfault on the other breaker.

Yeah something definitely was acting up with the oven causing crazy interference issues. What’s crazy is the media room afci circuit is directly above our kitchen where the oven is. That’s the only afci circuit that tripped and blew out two surge protectors while we were using the oven.

 

[ptonsparky]

I would have put the spd outside. Is this tract housing? I would bet a bunch of them are like that. Those contractors do cookie cutter jobs with unqualified help.

I agree the SPD, and all the bare, should have been in the SD.

 

[Phelpstx]

I agree the SPD, and all the bare, should have been in the SD.

The builders electrician is going to come back out and check all of the outlets throughout the house. The inspector was ok with having the gas line bond, and the low voltage bond in the main lug panel. I thought this was a code violation and that the gas line bond, and low voltage should have been bonded at the first means of disconnect outside.

I contacted our utility company tonight and confirmed we had some power outages / surges here the last month which would have happened around the same time we started experiencing issues with the oven.

I know since we moved in we have had 5-6 power outages with surges. Is there any reason to be concerned about the insulation on the Romex inside the walls if we had a surge without having our electrical system properly grounded?

I’ve seen what lightning could do to insulation of the wiring but was curious if heavy surges could cause damage to the insulation without having the main lug panel properly grounded.

Thanks

 

[ptonsparky]

The builders electrician is going to come back out and check all of the outlets throughout the house. The inspector was ok with having the gas line bond, and the low voltage bond in the main lug panel. I thought this was a code violation and that the gas line bond, and low voltage should have been bonded at the first means of disconnect outside.

I contacted our utility company tonight and confirmed we had some power outages / surges here the last month which would have happened around the same time we started experiencing issues with the oven.

I know since we moved in we have had 5-6 power outages with surges. Is there any reason to be concerned about the insulation on the Romex inside the walls if we had a surge without having our electrical system properly grounded?

I’ve seen what lightning could do to insulation of the wiring but was curious if heavy surges could cause damage to the insulation without having the main lug panel properly grounded.

Thanks

Anything is possible with lightning.
The low voltage stuff can be bonded about anywhere. Most don't worry about a gas meter. Must be a local requirement.