Wiring question

[California]

????

Red and two greens. That's not even on the chart! (click the picture). Can anybody interpret this?

 

[PILOON]

My guess is that the neutral and ground are tied together somewhere, at pannel or in the outlet.

 

[LD1]

Is the middle light green for sure??

It kinda looks like the light on the right is casting over to the middle???????

If that is the case, it looks to me like Red...White...Green which would be hot and ground reverse.

PS, I have never seen a meter like that. Perhaps if we knew what you are dealing with and what problems you are having we could better assist

 

[Craig Clayton]

I do not use that kind of meter, for general electrical work. That is used by the hydro inspection on a new installation when all the receptacles are powered up. It is very quick and accurate to find reversed connections. You just plug it and the lights light up if correct. If the lights are wrong you get a deficiency report. A inspector may check 10% at random if all looks good, if he feels there is problems then he will check 100%.
Most electrical tradesman use a straight volt meter because we want a single value for each touching of the wires. This information is then run through the human brain to determine the problem.
Maybe the meter is bad. Here are some phrases I have used before.
1 Use an know live circuit or source to test your meter.
2 Use an know working load ie 12volt head lamp when connecting a circuit on your 12 volt tractor or 120 Vac radio on a house receptacle.

Craig Clayton

 

[podagrower]

I've seen similar on my tester, but usually the two lights on the left will be dimmer (can't really tell from the pic). If that is the case, it is a neutral or ground issue, from my experience it is usually an open ground from a bad connection or the installation of 3 prong receptacles where there is no ground.

 

[Willl]

My guess is that the neutral and ground are tied together somewhere, at panel XXXXXXXXXXXX

Aren't they all ?

 

[skipmarcy]

Aren't they all ?

Our local utility requires a bond screw in the main panel.

 

[kenmac]

I also use these outlet testors ( not like this 1) I would say it's open ground. as in that outlet isn't grounded

 

[Willl]

Open ground would be 1 green light in the center.

 

[kenmac]

Open ground would be 1 green light in the center.

Yep, I agree. Looked again. Looks like it's showing red & green.

Re wire the outlet

 

[California]

My guess is that the neutral and ground are tied together somewhere, at panel or in the outlet.

Is the middle light green for sure??
Perhaps if we knew what you are dealing with and what problems you are having we could better assist.

I've seen similar on my tester, but usually the two lights on the left will be dimmer (can't really tell from the pic). If that is the case, it is a neutral or ground issue, from my experience it is usually an open ground from a bad connection or the installation of 3 prong receptacles where there is no ground.

The center LED is green and is as strong as the right one when viewed head-on.

The left, red, LED isn't as bright as the two greens.

My other, beige tester (new) shows center green only - 'Open Ground' - in that barn outlet where the red tester gave the weird reading.

I thought this barn circuit was fed with grounded cable, but it's old cable. The cable outer cover isn't plastic, it's the same outer dimensions as plastic but its silver painted over black, woven nylon or something. WWII army surplus?? Dad was a packrat and his strong advice was to bulldoze everything and start over as soon as he was gone.

The house and barn are so old that I don't think there was electricity initially. I'm certain there has never been a code inspection here - a couple of year ago the Building Permit department gave my house number to a new neighbor because they didn't know I exist! (I got the address back. I wish the tax assessor never hear of me either!)

The barn sub-panel and this outlet were added by DIY amateurs about 1970. I found 3-prong outlets in the house attached to 14-2 wiring (no ground) so this barn outlet could be the same.

What got me started testing everything was a tingle I got in the house from the old 1950's chromed percolator. That kitchen counter outlet tests Hot Neutral Reversed. The tingle disappeared when I turned over one end of the percolator's cord to feed Hot down the other wire. (non-polarized plug at both ends of the percolator's cord). Obviously, this could be deadly.

Kenmac, Will - I will definitely start by rewiring the kitchen outlet. What I learn there should help me see what is going on in the barn.

I think there is a ground connection to the water pipes at the main box and also a ground rod out at the barn's sub-panel. I have read that Neutral and Ground should be bonded only at the main panel but I expect the barn panel has them bonded also. Is that a problem? When I inherited the place 10 years ago I repaired a half-dozen plumbing leaks, and I suspected electrolytic action caused the corrosion. Would bonding ground/neutral two places 100 ft apart cause that?

 

[SPIKER]

It depends on how the place is wired to/from the barn & home.

If there are 2 different runs of power service entrance cable from the meter then the barn panel and the home panel both need to have the Neutral and the Ground Bonded in their respective panels. Both BARN and HOME need to have their own ground rods grounding systems regardless. The two systems can be tied together with copper but only through the service conductors and is not the typical way for it to be done. The common way back in the day (probably how your place was done) was to run a power into the home then put a breaker into the home then run 2 wires out to the garage and or barn. Often making both wires hot to have 220volts out int he barn/house. They would then stick a ground wire out to the barn and basically would not have a Neutral Wire. The Barn Ground was the Neutral and the Neutral and Ground were bonded together in the barn (or NOT.) In a few cases they used 3 wire and ran 220 and a Neutral added a ground rod (Or NOT) and run outlets. which is where issues often arose. People did things however they though would work without much regard to safety. I have personally run into places that had a single HOT wire run several hundred feet and the people tied the Neutral ground in the remote building to the siding & gutters for a neutral left like this. Usually just powering a light or two but voltages were like 80 volts

It seems to me there could be several problems with the reading on the GB meter. 1 the Hot Neutrals reversed. and probably a voltage issue as well which is where there may be an open neutral such as what I found in other places.


Mark

 

[California]

The common way back in the day was to run a power into the home then put a breaker into the home then run 2 wires out to the garage and or barn. Often making both wires hot to have 220volts out int he barn/house. They would then stick a ground wire out to the barn and basically would not have a Neutral Wire. The Barn Ground was the Neutral and the Neutral and Ground were bonded together in the barn (or NOT.) In a few cases they used 3 wire and ran 220 and a Neutral added a ground rod (Or NOT) and run outlets.

Spiker, thanks. I'm just getting up to speed on this. Most of that went over my head.

I just went and looked. The house panel has a 200A main breaker. From there, the conductors out to the barn sub-panel are two insulated black and one bare aluminum. Each conductor looks to be least 4ga, large than a pencil. 100A main breaker at the top of the barn's sub-panel.

Is that done right so far? Is it code for that single bare wire to serve as both 220V Neutral and the Ground?

 

[SPIKER]

Spiker, thanks. I'm just getting up to speed on this. Most of that went over my head.

I just went and looked. The house panel has a 200A main breaker. From there, the conductors out to the barn sub-panel are two insulated black and one bare aluminum. Each conductor looks to be least 4ga, large than a pencil. 100A main breaker at the top of the barn's sub-panel.

Is that done right so far? Is it code for that single bare wire to serve as both 220V Neutral and the Ground?

California so far that is OK from most places. Remember this place is older and until you sell and or start to update then you are off the hook for bringing it up to new code you need to only make sure that the connections on both ends are still GOOD & that the breaker is OK on both ends. I'm am guessing that you have a breaker in the HOME panel that is sending out the 2 black wires & the single bare wire to the barn?

Are these above ground FLY WIRE or are they buried in ground.? Reason I'm asking is the Bare Aluminum will rot under ground and you will loose your Neutral Connection back to the main home junction box. There needs to be a GROUND bar/rod and or Perimeter Ground system at the barn. The Barn Ground and Neutral should not be bonded together in this case there needs to be separate Ground/Neutral at the barn.

Mark

 

[California]

California so far that is OK from most places.

guessing that you have a breaker in the HOME panel that is sending out the 2 black wires & the single bare wire to the barn?

Good!

Yes there's a 100A breaker at both ends of the barn feeder.

Are these above ground FLY WIRE or are they buried in ground.? Reason I'm asking is the Bare Aluminum will rot under ground and you will loose your Neutral Connection back to the main home junction box.

OK I need to verify continiuty of that bare Neutral. The cables go under the house deck then go into iron pipe to cross the driveway. That pipe is a long U shape, and likely has water in it after 40 years.

There needs to be a GROUND bar/rod and or Perimeter Ground system at the barn. The Barn Ground and Neutral should not be bonded together in this case there needs to be separate Ground/Neutral at the barn.
Mark

Not bonded? Why? I expect they are.

The barn's ground rod is there but it may be inadaquate, 4 ft of rebar or something. How about adding a tie to the welded mesh in the slab also? I see an exposed corner of the mesh and it's heavy gauge, maybe 0.100".

 

[SPIKER]

Hi California

Not sure if you have a good meter or know how to use one but there are a few checks that you can do to see how the ground is as well as if that Neutral wire is grounded to the metal pipe in the dirt. I would imagine that the bare Aluminum wire has gotten into pretty bad shape after all those years probably submerged in water inside that rusty metal pipe.

You can tie to that metal mesh in the slab to the existing ground rod but I would also tie it to a DEEP GOOD ground rod (8AWG bare copper min.) That still does not help to get the correct Neutral Wire back to the main panel should you find the aluminum is not conducting well anymore and may be part of your problems. Having a GOOD ground at the barn is needed as i there is a short then you need to be able to drain the short & pop the breaker if the ground at the barn is pour then the short fault wont clear the breaker and basically just overload the circuit slowly heating soemthing up until something melts/burns/ignites.

They want the Ground & Neutral separate so that you dont create ground loops through the ground wire. Remember that there can be a lot of resistance in a few hundred feet of dirt especially if it is dry or contains higher solids low moisture. What I'm told can happen is a constant trickle of current naturally from one rod to the other and this like salt on your car causes these stray currents to eat away at all the connection points. The system will eventually fail (somewhere) when that happens. I personally see the benefit of added grounds but that is not the NEC wisdom at this time.

Mark

 

[California]

Not sure if you have a good meter or know how to use one but there are a few checks that you can do to see how the ground is as well as if that Neutral wire is grounded to the metal pipe in the dirt. I would imagine that the bare Aluminum wire has gotten into pretty bad shape after all those years probably submerged in water inside that rusty metal pipe.

I'm familiar with using a meter for simple electronics stuff, testing a pc power supply or the resistance of the fuser (heater) in a laser printer. It hadn't ocured to me that the aluminum neutral wire in effect is connected to ground where it goes through the wet rusty underground pipe. I just learned something here.

You can tie to that metal mesh in the slab to the existing ground rod but I would also tie it to a DEEP GOOD ground rod (8AWG bare copper min.) That still does not help to get the correct Neutral Wire back to the main panel should you find the aluminum is not conducting well anymore and may be part of your problems. Having a GOOD ground at the barn is needed as if there is a short then you need to be able to drain the short & pop the breaker if the ground at the barn is poor then the short fault wont clear the breaker and basically just overload the circuit slowly heating soemthing up until something melts/burns/ignites.

I should just buy a proper ground rod then, and settle that question.

As for testing continuity of the Neutral from the main panel out to the barn what do you think of this:

• - Turn off main breaker.
• - Plug in a 100 ft extension cord in the barn, take the other end back to the main panel.
• - Test that the resistance measured from the neutral in the house end of this extension cord to the panel neutral, is less than the resistance from one end of the extension cord alone to its opposite end. (A circuit of parallel wires has less resistance than one wire).

I can't think of any other way to test for continuity and low resistance in the neutral feeder.

They want the Ground & Neutral separate so that you dont create ground loops through the ground wire. Remember that there can be a lot of resistance in a few hundred feet of dirt especially if it is dry or contains higher solids low moisture. What I'm told can happen is a constant trickle of current naturally from one rod to the other and this like salt on your car causes these stray currents to eat away at all the connection points.

I suspect this could cause the corrosion I see in the water pipes. In fact ... I'll bet the underground feeder from the house to the well, and the additional underground feeders from the barn to the next outbuilding and then to the one beyond, each includes a bare neutral with earth contact. There must be galvanic currents going everywhere. No wonder I have corroding pipes.

Thanks Spiker! You have given me several items to investigate.

 

[Willl]

It hadn't occurred to me that the aluminum neutral wire in effect is connected to ground

I've said it before, don't ALL neutrals end up at 'ground' somewhere ?

 

[California]

Yes.

But what I'm learning in this thread is you want Ground connected to a grounding rod in the earth at every panel, but Neutral is bonded to Ground only once at the main service entrance.

If Neutral is also grounded at some additional points it can cause a minor current through the earth, causing electrolysis and hence corrosion.

In my particular old farmhouse I have a lot of mis-wired stuff to sort out (Hot-Neutral reversed, Open Ground, etc). And I think I also have the multiple-Neutral-to-Ground issue which would explain the plumbing corrosion.

 

[Willl]

Wish we were closer Cal, during my travels of life, a bundle of 6' grounding rods followed me home. Been sitting in the garage past 4 yrs. Sounds you could use a few.