New home not properly grounded.

[ActionDave]

So many old houses had wood everything and no grounds. The danger came from the metal piping and water with electrolytes

I find some irony in the notion that the shock hazard that you had from the metal pipes didn't exist in rooms like the living and bedrooms until we "extended" the pipes those living spaces by adding equipment grounds to all the circuits.

 

[letgomywago]

I find some irony in the notion that the shock hazard that you had from the metal pipes didn't exist in rooms like the living and bedrooms until we "extended" the pipes those living spaces by adding equipment grounds to all the circuits.

I do see the benefit of where metal boxes or constuction methods are utilized that equipment grounds be used. But not every situation is one of those and we're about 80 years to late to state an argument on where and when there should be one.

 

[electrofelon]

. If you don’t have a properly grounded electrical system all of your equipment is going to be more vulnerable to damage from a surge.

.

In many cases it's not going to make a difference. Also, we would know whether we are talking about system grounding, equipment grounding, or equipment earthing or what to really analyze a situation. Imagine a surge coming in on the hot legs, how would any sort of equipment or system earthing mitigate that (other than assist in the operation of an SPD)? If there was a lightning strike or nearby strike that say hit the neutral, some grounding electrodes might help mitigate that a little bit, might, but I wouldn't hold my breath. I would go for the SPD route as being more likely to help.

 

[ptonsparky]

We have not had any issues since we stopped using the original oven that came with the house and got it replaced. It’s possible that since the original oven was never properly grounded that it got damaged from a surge. If you don’t have a properly grounded electrical system all of your equipment is going to be more vulnerable to damage from a surge.

They did insulation resistance testing with a Megger for the oven wire and it tested good. So far after we got our system grounded properly and the oven replaced we haven’t had any issues.

I’ve had experience with a home not being properly grounded that got hit with a surge from lightning that caused the home later to catch on fire.

Nope. Still not convinced.

 

[kwired]

So many old houses had wood everything and no grounds. The danger came from the metal piping and water with electrolytes

Them old houses were supplied by a grounded system. Not having an electrode connection at the house doesn't make the system ungrounded. So those metal water pipes were still electrically continuous to the underground supply pipe and therefore still have full voltage between ungrounded conductors and those grounded pipes.

If you had a true ungrounded system, the first fault to water pipe ends up creating an unintended grounded conductor out of that conductor but there is no shock hazard other than to other ungrounded conductors.

I have run into issues a few times with old metallic sewer lines causing mild shocks, usually in bath tubs or showers. Problem is almost no one bonded the sewer piping, so it is at true earth potential. The water piping is bonded to service neutral, but any voltage drop imposed on S/N will exist between the water faucet(s) and the metal tub drain. Might only be 2-3 volts but standing in the water and touch the water faucet or even water spout and you get hammered by it. Running a bonding jumper between water piping and sewer piping solved the problem every time.

 

[kwired]

We have not had any issues since we stopped using the original oven that came with the house and got it replaced. It’s possible that since the original oven was never properly grounded that it got damaged from a surge. If you don’t have a properly grounded electrical system all of your equipment is going to be more vulnerable to damage from a surge.

They did insulation resistance testing with a Megger for the oven wire and it tested good. So far after we got our system grounded properly and the oven replaced we haven’t had any issues.

I’ve had experience with a home not being properly grounded that got hit with a surge from lightning that caused the home later to catch on fire.

We need more details to really know what was happening there. If you were getting shocked say anytime you touched the oven and maybe the sink, it could be as simple as there was no bond between electrical and the water piping and the shock was nothing more than the voltage drop imposed on the service neutral which is normal and unavoidable.

 

[ptonsparky]

Ran into issues with unbonded metallic sewer or drain lines more than once. We bonded them whenever we put on a new service.

 

[letgomywago]

Them old houses were supplied by a grounded system. Not having an electrode connection at the house doesn't make the system ungrounded. So those metal water pipes were still electrically continuous to the underground supply pipe and therefore still have full voltage between ungrounded conductors and those grounded pipes.

If you had a true ungrounded system, the first fault to water pipe ends up creating an unintended grounded conductor out of that conductor but there is no shock hazard other than to other ungrounded conductors.

I have run into issues a few times with old metallic sewer lines causing mild shocks, usually in bath tubs or showers. Problem is almost no one bonded the sewer piping, so it is at true earth potential. The water piping is bonded to service neutral, but any voltage drop imposed on S/N will exist between the water faucet(s) and the metal tub drain. Might only be 2-3 volts but standing in the water and touch the water faucet or even water spout and you get hammered by it. Running a bonding jumper between water piping and sewer piping solved the problem every time.

The real old ones were not grounded

 

[LarryFine]

I believe the potential (no pun intended - honest) for dangerous voltages between both electrical and other systems and earth would be much greater without earthed electrical systems.

Primary distribution systems would have thousands of volts to earth even without a grounded neutral, and accidental primary/secondary contacts happen often enough to be a concern.

 

[letgomywago]

I believe the potential (no pun intended - honest) for dangerous voltages between both electrical and other systems and earth would be much greater without earthed electrical systems.

Primary distribution systems would have thousands of volts to earth even without a grounded neutral, and accidental primary/secondary contacts happen often enough to be a concern.

I'd personally rather we do better line side distribution protection like Europe. Also would prefer a completely redone ad-hoc style production system but my personal preference for any system of this scale carries little if any weight.

 

[kwired]

The real old ones were not grounded

If your service/distribution box is a metal cabinet, it probably was required to have a GES. If it is a slate cabinet with porcelain fuse holders inside, it may not originally been required to have a GES.

 

[kwired]

I believe the potential (no pun intended - honest) for dangerous voltages between both electrical and other systems and earth would be much greater without earthed electrical systems.

Primary distribution systems would have thousands of volts to earth even without a grounded neutral, and accidental primary/secondary contacts happen often enough to be a concern.

Yes and it would be capacitively coupled voltages most the time.

I connected a new irrigation well service last spring. ~ 1400 feet from disconnect on transformer pole to the equipment served. I had the equipment end all connected and went to the pole disconnect to make up connections there. The grounded conductor sparked when I touched it to the lug. I measured about 10 volts from the supply side neutral to earth. I asked POCO to make sure they had no neutral issues (primary was 12.47/7.2 kV), although it was all new build for about 3/4 mile. They called me back after checking things out - has to be from that 230kV transmission line on opposite side of road and capacitance. I don't like it but not sure what to do about it. May not be any significant power behind it but probably still will shock you. Went out to point on center pivot and still read around 10 volts from frame of machine to earth. Can see someone changing flat pivot tire or broken gear box, these things break down while using them so everything is typically still wet from watering and this just may not be a great combination.

 

[letgomywago]

If your service/distribution box is a metal cabinet, it probably was required to have a GES. If it is a slate cabinet with porcelain fuse holders inside, it may not originally been required to have a GES.

I've ripped out multiple wood box fuse holder type services. They fused the nuetral back then also

 

[kwired]

I've ripped out multiple wood box fuse holder type services. They fused the nuetral back then also

My best guess is originally there maybe was no grounded conductor on a lot of those installs and they fused both conductors. Also was predominantly just two wire service on a majority of them. Grounding likely became common practice if you had a three wire system and of course you grounded the center tap (neutral).

 

[ruxton.stanislaw]

Yes and it would be capacitively coupled voltages most the time.

I connected a new irrigation well service last spring. ~ 1400 feet from disconnect on transformer pole to the equipment served. I had the equipment end all connected and went to the pole disconnect to make up connections there. The grounded conductor sparked when I touched it to the lug. I measured about 10 volts from the supply side neutral to earth. I asked POCO to make sure they had no neutral issues (primary was 12.47/7.2 kV), although it was all new build for about 3/4 mile. They called me back after checking things out - has to be from that 230kV transmission line on opposite side of road and capacitance. I don't like it but not sure what to do about it. May not be any significant power behind it but probably still will shock you. Went out to point on center pivot and still read around 10 volts from frame of machine to earth. Can see someone changing flat pivot tire or broken gear box, these things break down while using them so everything is typically still wet from watering and this just may not be a great combination.

What sort of current can you pull from that?

 

[kwired]

What sort of current can you pull from that?

IDK at this point. Is a regular client I do a lot of work for though and have considered going out there sometime and checking it out some more for things like how much current can it pull.