Residential Electrical Grounding

[joefbeams]

Old House was wired in 1949 with 30 amp main fused panel which was common in rural homes. It was later upgraded to 100amp main (with fuses for the branch circuits) serving the 30 amp as a sub panel. There appears to be 2 small grounding conductors coming from those panels to a driven grounding rod. The wiring was later upgraded to a 200amp main panel (provided by the power distributor free for customer installation) mounted outside at the meter: the 200amp main panel serves directly the existing 100amp panel as a sub panel; and 2 or 3 branch circuits protected by breakers. The grounding Conductor is connected to the incoming service ground (above the meter and 200amp panel) and runs to the driven grounding rod along with the 2 grounding conductors from the exiting panels as mentioned above. The washer and dryer was relocated to a new location-- grounded together to a different driven grounding rod. The question: is the house and Washer/-Dryer properly grouned and if not --how to correct. Joe Boehms

 

[wyliesdiesels]

A grounding electrode(UFER, ground rod, etc.) and an EGC(equipment grounding conductor) serve 2 different purposes!! A grounding electrode is to ground lightning and an EGC is to provide a fault current path.

As to your question: if the outlets of the appliances are properly grounded, meaning a ground wire connects the grounding terminal of the outlet to the ground bus bar in the serving panel, then theyre fine. But u said theyre connected to a ground rod, which is INCORRECT! A ground rod does not provide a fault current path back to the panel for a breaker to be able to trip when its suppose to! This should be corrected!!

But it sounds like your house is properly grounded via the ground rod!

 

[soj]

One thing to check is if the 30A and 100A panels are correctly wired as sub panels. Are the neutral and ground bus bars separate bars, is the neutral isolated from the panel, and is the ground bar bonded to the panel? Are there 4 wires feeding each of the sub panels? The neutral and ground bars should only be bonded together (or be one bar) in the 200A panel IF it it the first means of disconnect. I can imagine that that original 30A fuse box only has two wire circuits out of it.

I am not an electrician, so maybe some of you who are can answer this.

Isn't there supposed to be only one grounding electrode conductor for the whole system (when all the panels are in the same building)? And it should be grounding the main panel and bus bar, the other panels are grounded via the 4th wire to each panel. Someone correct me if I am wrong. Not sure how this would work with an old fuse box.
jp

 

[wyliesdiesels]

One thing to check is if the 30A and 100A panels are correctly wired as sub panels. Are the neutral and ground bus bars separate bars, is the neutral isolated from the panel, and is the ground bar bonded to the panel? Are there 4 wires feeding each of the sub panels? The neutral and ground bars should only be bonded together (or be one bar) in the 200A panel IF it it the first means of disconnect. I can imagine that that original 30A fuse box only has two wire circuits out of it.

I am not an electrician, so maybe some of you who are can answer this.

Isn't there supposed to be only one grounding electrode conductor for the whole system (when all the panels are in the same building)? And it should be grounding the main panel and bus bar, the other panels are grounded via the 4th wire to each panel. Someone correct me if I am wrong. Not sure how this would work with an old fuse box.
jp

Yes, thats a good point. The 'subpanels' should be checked to make sure theyre properly connected/setup!

And yes, there should be ONLY 1 GEC! Good catch!! I missed that on first glance over!

 

[zmaxmotorsports]

Id say it should also be bonded to the street side of water meter on copper water service also if it is available.

 

[CNGsaves]

This is America or where??? Says house is "rural" but what state and city have jurisdiction over it's electrical code??

Now would be good time to Update GJ Profile with Country / State / City.

Situation sounds rather unique. Any pics of all these panels and grounds??

 

[wyliesdiesels]

Id say it should also be bonded to the street side of water meter on copper water service also if it is available.

Yup! OP should check this too!

 

[soj]

This is America or where??? Says house is "rural" but what state and city have jurisdiction over it's electrical code??

Now would be good time to Update GJ Profile with Country / State / City.

Situation sounds rather unique. Any pics of all these panels and grounds??

Yes, you know we love pics, and I would esp. like to see these boxes and their wiring...

 

[sberry]

I personally would want single point grounding at the main. I agree this could use a bit of further investigation. Many of these old panels were designed as service entrance equipment, they have bonded neutral. They are fed with 3 wire and now a wire has been added as an alternate pathway for neutral currents.

The washer dryer is not correct. If this is a 2 wire 120 feed and been rigged to a 3 wire recept to a ground rod not good. Same if this is a dryer 4 wire recept to a 3 wire cable?? Run a new pice of romex for the washer back to either tha main or a (ideally) 4 wire fed breaker panel.

Some of these rig ups used steel pipe between entrance and second panels, I always make sure they are tight and on occasion have ran a wire from neutral main to ground in second.

I wan in a house not too long ago where a second had been added inches away from the first with steep ******. Ideal or not it was treated as one unit, they didn't use a ground bar in the second, installed the bond screw although it was irrelevant to some extent and they landed the grounds on the Nbar.

There were minor details that could use work, this in a 60 something house but the equipment was grounded, main detail I might have added was a ground wire to the well casing and might have changed the dryer from 3 to 4 since it was easy.