Help me understand how electrician set this sub panel up

[dh128905]

I can’t follow this guy when he’s explaining this to me. I have no electrical experience, but just doesn’t seem right to me. 100 amp sub panel in detached garage.

What are those 2 vertical metal pieces inside the bus bars? It looks like he connected the EGC to it? I thought those were connections for the breakers

He said the bonding screw is in there to just connect the ground bus bar to the panel, and that neutral and grounds are NOT bonded.

Shouldn’t he have just put a separate grounding bus bar in there? And leave the other 2 bus bars for neutrals only? Remove the green screw completely…????

I’ve spent an hour reading about this stuff online, seems pretty simple. What am I missing?

 

[billconner]

Following...

 

[sparky 1971]

He's right. The bar on the right is bonded and will be for the grounds and the left will be the neutral, the two are not connected to each other. The vertical thingamajigs are for there to hold the breakers. And the wire isn't connected to anything yet, It's just sitting there waiting to be put on the ground bar.

 

[dh128905]

He's right. The bar on the right is bonded and will be for the grounds and the left will be the neutral, the two are not connected to each other. The vertical thingamajigs are for there to hold the breakers. And the wire isn't connected to anything yet, It's just sitting there waiting to be put on the ground bar.

Great, thanks! And do you recommend leaving that right one as the bus bar, or installing a separate bus bar?

Looks like I’ll have plenty of spots as is. I’ll probably never fill up even half of those slots.

Glad to hear he knows what he is doing! Guy is so scatter brain I was worried

 

[sparky 1971]

Great, thanks! And do you recommend leaving that right one as the bus bar, or installing a separate bus bar?

Looks like I’ll have plenty of spots as is. I’ll probably never fill up even half of those slots.

Glad to hear he knows what he is doing! Guy is so scatter brain I was worried

The only reason to add another bar would be if there wasn't enough room for the neutrals. Then the bonding screw would go in the trash and the bar that ties the two sides together goes back. Leave it alone.

 

[dh128905]

Appreciate it. And I take back that he knows what he is doing, because the cable he used is Service Entry (SER). Underground in conduit. Code is clear as day that is not allowed. Small town, I think he knows the inspector. The 3 conductors have the XHHW insulation, but the EGC only has the outer grey PVC jacket to protect it.

So yeah, now I’m questioning everything he does and spending my Sunday researching this stuff. Wish I would have educated myself before he started, but I kind of thought… licensed electrician no reason to check him on such an easy job.

He also only put one grounding rod in.

this guy was a lineman, did residential electric, and now teaches at one of the colleges nearby.

 

[sparky 1971]

Then it's time to call him out and make sure the inspector knows what 338.12(A)(2) says about SE cable

 

[mm08822]

He could have left the neutral bars alone and just added a grd bar on either side.

It is also OK with what he has done to reconfigure both bars for separate purposes.

He needs a second grd rod unless he can prove 25 ohms or less to grd. He may just have access to the needed equipment being a teacher. However, it needs to be within current calibration windows. Still easier to just drive the 2nd rod. Lookup supplemental ground rod requirement.

Who is the panel mfr?

 

[dh128905]

He does know the code. I called him out, and he recited 338.12 back to me. He seems to think because this SER is wet rated with the HXXW and grey PVC, that supersedes that code. He won’t admit any wrongdoing. He kept asking me “if that conduit was above ground with the SE cable, and full of water, how would that be any different than being underground and full of water. There is 2” PVC protecting it from any physical damage, so water is the only concern.”

I asked him how long he thinks that grey pvc covering will take to degrade and leave the EGC exposed to water, and he said decades.

He’s full of it, and I’m done with him. Certainly don’t want him back at my house.

 

[dh128905]

He could have left the neutral bars alone and just added a grd bar on either side.

It is also OK with what he has done to reconfigure both bars for separate purposes.

He needs a second grd rod unless he can prove 25 ohms or less to grd. He may just have access to the needed equipment being a teacher. However, it needs to be within current calibration windows. Still easier to just drive the 2nd rod. Lookup supplemental ground rod requirement.

Who is the panel mfr?

GE 32/32 panel. would have been very easy to drive a second ground rod.. I don’t get it

 

[wyliesdiesels]

He is wrong about the ser. Cannot go underground. His example doesnt matter either.

As for the panel, I prefer to have a neutral and ground bar on each side of the panel. It makes it less messy. There is even predrilled holes on each side for ground bars.

 

[dh128905]

He is wrong about the ser. Cannot go underground. His example doesnt matter either.

As for the panel, I prefer to have a neutral and ground bar on each side of the panel. It makes it less messy. There is even predrilled holes on each side for ground bars.

I agree he is wrong. He knows he’s wrong. Just won’t admit it.

Well stay tuned and I guess I’ll be a real life example of what happens to SER buried underground in conduit. Will be regularly testing the integrity. Most notably the EGC

 

[sparky 1971]

338.12 Uses not permitted
(A) Service -Entrance Cable. Service entrance cable (SE) shall not be used under the following conditions or in the following locations.
(1) Where subject to physical damage unless protected in accordance with 230.50(B)
(2) Underground with or without a raceway
(3) For exterior branch circuits and feeder wiring unless the installation complies with the provision of Part 1 of Article 225 and is supported in accordance with 334.30 or is used as messenger supported wiring as permitted in Part 2 of Article 336.

 

[sparky 1971]

I agree he is wrong. He knows he’s wrong. Just won’t admit it.

Well stay tuned and I guess I’ll be a real life example of what happens to SER buried underground in conduit. Will be regularly testing the integrity. Most notably the EGC

The inspector may not know it either if he's one of the do it all guys that used to hang drywall. 338.12(A)(2) is the reference above. The end.

 

[PCustoms]

I agree he is wrong. He knows he’s wrong. Just won’t admit it.

Well stay tuned and I guess I’ll be a real life example of what happens to SER buried underground in conduit. Will be regularly testing the integrity. Most notably the EGC

That's dumb.

How much do you owe the electrician?

If he won't fix it, fire him and take care of it yourself.

 

[dh128905]

He’s done and I already paid him. He’s not going to fix it, and I don’t have time to fight him. I also don’t want him back at my house. I’m overseas 5 months a year, and just left. Hence the time to research all of this.

The Run is 175’, the conduit has (4) 90 degree turns in it, and it’s buried 18” underground. Land graded and grass seed planted. I’m just going to keep a close eye on system integrity, and replace at first sign of problem.

 

[mm08822]

Hopefully you still owe final payment. Hold back until resolved.
Is there a signed contract with any details?

This guy seems like a real headcase if he thinks he can make up his own code and exceptions on the fly. You probably caught him off guard with your q's, compared to a clueless HO. If the inspector agrees with him, report him to the state agency. I'm sure someone above the inspector has some smarts.

The uninsulated grd wire will corrode. Did he run copper to the grd rod?

 

[sparky 1971]

He’s done and I already paid him. He’s not going to fix it, and I don’t have time to fight him. I also don’t want him back at my house. I’m overseas 5 months a year, and just left. Hence the time to research all of this.

The Run is 175’, the conduit has (4) 90 degree turns in it, and it’s buried 18” underground. Land graded and grass seed planted. I’m just going to keep a close eye on system integrity, and replace at first sign of problem.

The only real concern is going to be the ground wire, but you're not going to be able to keep an eye on it. If it decides to fail, it's going to fail, it will be somewhere in the conduit and you won't know unless something bad happens that should have caused the breaker to trip.

 

[dh128905]

The only real concern is going to be the ground wire, but you're not going to be able to keep an eye on it. If it decides to fail, it's going to fail, it will be somewhere in the conduit and you won't know unless something bad happens that should have caused the breaker to trip.

There’s no way to test for a failed EGC?

Hopefully you still owe final payment. Hold back until resolved.
Is there a signed contract with any details?

This guy seems like a real headcase if he thinks he can make up his own code and exceptions on the fly. You probably caught him off guard with your q's, compared to a clueless HO. If the inspector agrees with him, report him to the state agency. I'm sure someone above the inspector has some smarts.

The uninsulated grd wire will corrode. Did he run copper to the grd rod?

Yes on copper to ground rod. Agree with corrosion of EGC

 

[PCustoms]

There’s no way to test for a failed EGC?

Not effectively as a homeowner.

Report him and the inspector to the state.

Someone is going to have to pull that wire and put something correct in. I suggest not getting a permit.

 

[sparky 1971]

There’s no way to test for a failed EGC?

You can ohm it out now to get a baseline and keep checking it over the years, but if it gets down to one strand and is sitting in water, your baseline may never change unless it gets completely severed and that won't happen until years after you have forgotten all about it and stopped checking.

 

[dh128905]

You can ohm it out now to get a baseline and keep checking it over the years, but if it gets down to one strand and is sitting in water, your baseline may never change unless it gets completely severed and that won't happen until years after you have forgotten all about it and stopped checking.

Excuse my ignorance on the subject, but what about a simple outlet tester that shows if you have an open ground?

 

[PCustoms]

Excuse my ignorance on the subject, but what about a simple outlet tester that shows if you have an open ground?

You could have a strand of wire as thin as a hair that makes enough continuity to light a tester OK.

If you have an issue that requires the ground to clear, you're going to need the full gage of the wire.

 

[dh128905]

Ok thanks. 2 other things:

1. Will testing potential difference between neutral and ground at sub panel provide info on health of EGC?

2. Assuming all the GFI breakers are working as they should, how could a failed EGC still cause a fire or equipment damage?

these questions are just to help me understand how all these systems work.

 

[billconner]

I was wondering if you have a good local ground - rods or Ufer - what problems may arise if the ECG fails?

 

[sparky 1971]

Excuse my ignorance on the subject, but what about a simple outlet tester that shows if you have an open ground?

You will never show an open ground with a tester because of the ground rods, which aren't designed to carry fault current back to the neutral and trip the breaker.

 

[sparky 1971]

Ok thanks. 2 other things:

1. Will testing potential difference between neutral and ground at sub panel provide info on health of EGC?

Yes and no. That is where the baseline I mentioned above comes from. The EGC could be in the process of deteriorating, but the baseline not change due to water in the conduit. Water isn't as great of a conductor as Hollywood makes it out to be, but it could be enough that the meter won't pick up a change. Since I've never tried it, I can't swear to that, but it's a possibility.

2. Assuming all the GFI breakers are working as they should, how could a failed EGC still cause a fire or equipment damage?

these questions are just to help me understand how all these systems work.

If there is a ground fault inside, the breakers should pick it up and trip faster than the breaker in the house would even with a good EGC. However, in the future, when the EGC breaks down, there won't be anything protecting the feeder or the panel for the time when a lawnmower smashes into the riser conduit that is probably schedule 40 PVC but should be SCH 80. Is everything going to be GFCI protected? Just an FYI, GFCI's fail. They are supposed to fail to tripped, buy I've seen more than my share that appeared to be working fine but wouldn't trip when tested.

The bottom line is that as of the adoption of the 2008 NEC, there is supposed to be a GEC to separate structures. Before that, a three wire feed with a bonded neutral in the garage was the norm. As of the invention of SE cable, it hasn't been allowed underground. You need to get it fixed, whether by the installer or someone else. I don't see why any sane person would attempt to pull 175' of SER cable through conduit, 2" or not, with four 90°'s in the first place. Did he install the pipe then pull the cable or did he shove the cable through while he was gluing the pipe together?

 

[sparky 1971]

I was wondering if you have a good local ground - rods or Ufer - what problems may arise if the ECG fails?

Because ground rods are for lightning protection. There isn't enough conductivity in the earth to ensure fault current will get where it needs to go in order to trip the breaker. Some places are better than others, but no where is the soil a good replacement for a conductor.

 

[dh128905]

If there is a ground fault inside, the breakers should pick it up and trip faster than the breaker in the house would even with a good EGC. However, in the future, when the EGC breaks down, there won't be anything protecting the feeder or the panel for the time when a lawnmower smashes into the riser conduit that is probably schedule 40 PVC but should be SCH 80. Is everything going to be GFCI protected? Just an FYI, GFCI's fail. They are supposed to fail to tripped, buy I've seen more than my share that appeared to be working fine but wouldn't trip when tested.

The bottom line is that as of the adoption of the 2008 NEC, there is supposed to be a GEC to separate structures. Before that, a three wire feed with a bonded neutral in the garage was the norm. As of the invention of SE cable, it hasn't been allowed underground. You need to get it fixed, whether by the installer or someone else. I don't see why any sane person would attempt to pull 175' of SER cable through conduit, 2" or not, with four 90°'s in the first place. Did he install the pipe then pull the cable or did he shove the cable through while he was gluing the pipe together?

It’s a detached garage, so yes all the breakers will be GFI protected.

I had buried the conduit a straight shot to the front side of my garage, but the panel needed to be in the back instead of front (my mistake), So he fed the SER through the conduit I placed, then built the rest of the conduit as he fished it through. I wasn’t there for that part, but I can only imagine how miserable that was.

 

[mm08822]

Has this been inspected yet?

What town inspector?
What college does he teach at?

If this ever gets replaced, cutting a jbox in the conduit at the garage wall can leave the interior wiring untouched but adds splices.

What size ser and cb used?

 

[PCustoms]

@dh128905

I'm going to back up for a minute.

How do you know he ran ser underground?

Any chance there is a splice?

I don't see any ser jacket in that panel....

 

[sparky 1971]

@dh128905

I'm going to back up for a minute.

How do you know he ran ser underground?

Any chance there is a splice?

I don't see any ser jacket in that panel....

The bare aluminum ground is pretty much a dead giveaway and he probably stripped the jacket off back into the LB on the outside.

 

[dh128905]

@dh128905

I'm going to back up for a minute.

How do you know he ran ser underground?

Any chance there is a splice?

I don't see any ser jacket in that panel....

He readily admits it is SER. And this is what is printed on the outer jacket:

Kingwire e466712 sk 3 cond 1/0 mag + 1 cond 2 AMG AA-8000 AL Type SE style R XHHW-2 conductors 600 V XLPE

 

[PCustoms]

The bare aluminum ground is pretty much a dead giveaway and he probably stripped the jacket off back into the LB on the outside.

Well when you say it like that....


In my defense I've been in the sun all afternoon

 

[wyliesdiesels]

deleted

 

[Tundra1]

Code is crystal clear on it, but still curious why it is allowed in wet location but not underground. Would it be the assumption that underground is continuous wet whereas above ground is intermittent?

 

[dh128905]

Code is crystal clear on it, but still curious why it is allowed in wet location but not underground. Would it be the assumption that underground is continuous wet whereas above ground is intermittent?

It’s a good question. Presumably it can be above ground, and sitting in water. Why not insulated the EGC for a wet rated cable? Is the outer grey PVC coating more water resistant than is commonly believed?

 

[wyliesdiesels]

Has to do with sitting in water.

When its used above ground, its not gonna be sitting in water like it will in a conduit.

 

[Norcal]

Has to do with sitting in water.

When its used above ground, its not gonna be sitting in water like it will in a conduit.

You do not want a uninsulated aluminum grounding conductor in a underground conduit, failure will result, not sure if a bare copper conductor is permitted underground, either.

 

[dh128905]

Appreciate all these responses. I guess one positive thing is I’m learning a lot about residential wiring. Am I understanding the concern with EGC properly here:

#2 AWG EGC will quickly corrode without insulation. This will increase resistance of the EGC little by little, until it eventually fails completely. Said another way… The EGC, over time, will become less and less capable of clearing ground fault current. Essentially the EGC will have the current carrying capacity of smaller gauge wire over time.

I will not be able to effectively test for this corrosion, because all my multimeter tests will show normal until near complete failure has occurred.

Question. Do you think hot to ground would start showing less than 120 volts as this EGC corrodes over time?

More academic now, I know the cable needs to be replaced.

I do find it interesting they label this as a wet location approved cable. Wet location as defined by Section 100 includes “locations subject to saturation with water or other liquids.” That statement alone would lead me to believe that the SER should be able to live in water.

Wouldn't damp location be a more appropriate way to list SER? What kind of testing is required to achieve a wet location approved cable?