One Main/Meter, 200AMP service, 2 seperate 100Amp disconnects, two breaker boxes

[Ray Hunter]

Home has the above equipment. inspector is telling the home owner that the second panel located in the basement should not have Neutral and Ground bonded as it is a sub panel. it is not a sub panel being fed from the other breaker box it has its own main feed and disconnect. i need a code reference to show the inspector he is incorrect.

[Jerry Peck]

inspector is telling the home owner that the second panel located in the basement should not have Neutral and Ground bonded as it is a sub panel. it is not a sub panel being fed from the other breaker box it has its own main feed and disconnect. i need a code reference to show the inspector he is incorrect.

Unfortunately neither of you are correct ... but the inspector is not incorrect on what he is saying, just how he is saying it.

The ONLY place the neutral is bonded to ground is at the "service equipment" ... no place downstream of the service equipment.

The "service equipment" is the FIRST (and can be one or up to six) disconnect. Everything after the service equipment is (descriptively) 'not service equipment'. It is not a "sub panel" as that is a misnomer which confuses many people as to what is allowed where, as it has apparently confused you.

Think "service equipment" and 'other than service equipment'. I have been trying for years and years, decades even, to get people to stop using the term "sub panel" because it causes so much confusion to so many people. Some terms to use could be 'remote panel' (as in "remote" from the service equipment - which could mean it is sitting 'right next to the service equipment', but it is a separate panel), but the simplest term is simply "electrical panel" and then, as you did, state where it is located, i.e., the electrical panel in the basement ... seems simple enough.

So, yes, the inspector is correct in that the neutral is not permitted to be bonded to ground anywhere downstream of the service equipment, which, in your description, is the two 100 amp disconnects.

[jack davenport]

Please clarify the set up for me

From what I understand you have a dwelling with a 200 ampere electrical service that has 2 100 ampere disconnects that feed 2 100 ampere panels.
Questions:
Where are the 100 amp disconnects located ( inside ,outside, are they 100 amp main breakers in the panels)
Where are the panels located

[Ray Hunter]

Please clarify the set up for me

From what I understand you have a dwelling with a 200 ampere electrical service that has 2 100 ampere disconnects that feed 2 100 ampere panels.
Questions:
Where are the 100 amp disconnects located ( inside ,outside, are they 100 amp main breakers in the panels)
Where are the panels located

disconnects are located outside beside the Meter Box
there are 100 amp breakers in the disconnects
breaker panels are located one in the garage and one in the basement
and by bonded, I meant to the Box not to each other.

[Jim Robinson]

I take it this is your house, or someone you know. Do you have some photos? Total of four separate panels, or just two? Or are there 3? Take a photo of what it outside by the meter if you can.

[jack davenport]

ok so the service is those 2 exterior disconnect switches.
They should be rated " suitable for use as service equipment" and the grounding and bonding takes place at those switches.
The 2 interior panels are sub panels ( or remote panels - both the same thing) The grounds and neutrals shall be separate from each other in these panels.

So the inspector is correct. The service is the exterior switches and the interior panels are "sub panels" / "remote panels".

[Jim Port]

You will not find a code reference since the other inspector is correct. The disconnects are the services. The panels should have 4 wire feeder to them and have the neutrals isolated from ground.

Jerry, it is just as bad when someone thinks a panel is a service simply because it has a main breaker.

[Jerry Peck]

Jerry, it is just as bad when someone thinks a panel is a service simply because it has a main breaker.

Agreed, which is why I specified the first disconnect, and that there can be one or up to six (so as to not add confusion because he said that there were two disconnects at/next to the meter.

It would be good to have a "panel main" at each panel - it is not required and is seldom found. Kind of like having a GFCI receptacle device at each receptacle which requires GFCI protection - not required and seldom found.

[Jerry Peck]

Ray,

The answer to this question will let you know how easy ... or difficult ... correcting that condition may be:
- Are the feeders to the electrical panels (feeders from the service equipment) 3-wire (H-H-N/G) or 4-wire (H-H-N-G)?

[ROBERT YOUNG]

To start, would not the service be unknown? Typically it is determined by the main disconnect.
So how is this service ampacity determined?

[Jerry Peck]

To start, would not the service be unknown? Typically it is determined by the main disconnect.
So how is this service ampacity determined?

Which brings up a good point - knowing the precise service ampacity is overrated.

Suffice it to report that, as described, the service consists of two 100 amp main service disconnects (I am presuming, of course, that the service entrance conductors and feeders are suitably rated, as well as the panels being suitably rated; i.e., the feeder conductors are sized for at least 100 amps, and the panels buses are rated for at least 100 amps.

[ROBERT YOUNG]

Yes the feed size is important. And it would be a small feed if rated at 100 amp.:eek:

Jerry, et al, I was a bit taken back by the thread for another reason. I ran into the same electrical setup on 2 to 3 occasions and reported the following, and it does not change no matter how many disconnects, up to six that is.

Main disconnect 100 amp. Although the service size is determined by the main-disconnect rating during a home inspection, one can reasonably predict it is higher. 400 amp / 600 V. would be a typical residential service size.
I report the equipment manufacturer, ie: Square D, 100 amp QO 20 space, 102/240V, AC/CA, 3 wire, 1P.
There can be up to 6 disconnects in the home/building, but the main disconnect is the highest service rating. That home is rated at 100 amp., with 2 disconnects. Likely the home was renovated into a larger home at one point.

[Jim Port]

Robert, how can you report a 100 amp service when there are two panels of 100 amps? Suppose the 100 was originally enough. Now an addition is built or a hot tub is adding putting a load calculation over the 100 amps. It is cheaper to add a second 100 vs changing out the 100 to a 200. The capacity is there, it is just in two panels instead of one.

[Don Hawley]

Ray,

The answer to this question will let you know how easy ... or difficult ... correcting that condition may be:
- Are the feeders to the electrical panels (feeders from the service equipment) 3-wire (H-H-N/G) or 4-wire (H-H-N-G)?
Assuming it is the 3-wire (H-H-N/G) with PVC conduit and no ground wire to the remote panel, where do you attach the ground wires for the branch wiring if the neutral is isolated? Since you are not supposed to connect grounds and neutrals on the same bus after the service panel and where do you bond the metal panel case?

[ROBERT YOUNG]

I concur, Jim. Don't get me wrong. That is why I posted #10. The service size is unknown and Jerry followed up with #11.
As well, to measure the ampacity one requires awg and cable material, al/cu and accurate measurement conducted by someone qualified.

Ray Hunter stated; fed from the other breaker box has its own main feed and disconnect.
I take that to mean, there are (2) seperate line feeds for each SEC.
Note: I could be mistaken in my interpretation, but that is how I read it.

As expressed, during my observations, in the electrical section, under service rating; Although the service size is determined by the main-disconnect rating, 100 amps in this case, during a home inspection, one can reasonably predict it is higher. 400 amp / 120/240 v would be a typical residential service size.
Any recommendation/s thereafter, suite what was inspected.

[Jerry Peck]

I report the equipment manufacturer, ie: Square D, 100 amp QO 20 space, 102/240V, AC/CA, 3 wire, 1P.
There can be up to 6 disconnects in the home/building, but the main disconnect is the highest service rating. That home is rated at 100 amp., with 2 disconnects. Likely the home was renovated into a larger home at one point.

Robert,

So many curious things in there, some of which are almost surely typos: (I presume you are referring to the service equipment described in the thread with two 100 amp mains)

- "I report the equipment manufacturer, ie: Square D, 100 amp QO 20 space, 102/240V, AC/CA, 3 wire, 1P."
- - I presume that 102/240V is a typo for 120/240V.
- - What is the "CA" in AC/CA?

- "There can be up to 6 disconnects in the home/building, but the main disconnect is the highest service rating."
- - Huh? One does not add up the disconnects to determine the service size, nor does one 'take the highest rated breaker' as the service size either as the service size is not dependent on 'the highest rated breaker' when there are more than one disconnects (and up to six).

- "That home is rated at 100 amp.,"
- - Huh? That home has two 100 amp main service disconnects. Report it as such ... without making incorrect assumptions.

- "with 2 disconnects."
- - Again, you are not describing what you are seeing. Report is as having two 100 amp main disconnects, not as 100 amp and not as 200 amp.

- "Likely the home was renovated into a larger home at one point."
- - Report what you see and leave the conjecturing up to some unprofessional person. I have seen many new construction homes with two, three, even four main disconnects ... yes, is separate enclosures - I am not referring to multiple breakers stacked in a panel.

[ROBERT YOUNG]

Yes typo.:sorry:

The intent, identification from electrical panel door labels.
IE: Commander Cat No. QL36125
125 AMP., 120/240V., AC/CA.

Get back to your questions later.

[Jerry Peck]

Assuming it is the 3-wire (H-H-N/G) with PVC conduit and no ground wire to the remote panel, where do you attach the ground wires for the branch wiring if the neutral is isolated? Since you are not supposed to connect grounds and neutrals on the same bus after the service panel and where do you bond the metal panel case?

With that assumption, being a 3-wire feeder ... there are two basic solutions: 1) replace the feeder if not in conduit; 2) pull in a grounding conductor if in conduit ... and if the conduit is sized to allow for the grounding conductor ... otherwise see 1).

- - - Updated - - -


400 amp / 600 V. would be a typical residential service size.

Robert,

I forgot to ask about the above in my other post: 600 volt? That was one of what I think were typos, but I forgot to ask about ti.

[ROBERT YOUNG]

Robert,
- "with 2 disconnects."
- - Again, you are not describing what you are seeing. Report is as having two 100 amp main disconnects, not as 100 amp and not as 200 amp.

Although some may agree while others not, maybe not seeing what I am explaining. :peep:;)

Would not the equipment disconnect rated 100, 125, 200 amp, be the highest rated main disconnect become that service rating in a typical/usual residential home?
Typical/usual being the keywords. IE: Without up to 6 disconnects.
IE: As per the OP's post. 2 feeds. 2 panels. The (2) service equipment rated at the same ampacity.

[Jerry Peck]

Although some may agree while others not, maybe not seeing what I am explaining. :peep:;)

Would not the equipment disconnect rated 100, 125, 200 amp, be the highest rated main disconnect become that service rating in a typical/usual residential home?

Only if ... IF ... they were in series (such as a 150 amp main in a panel).

If there are multiple disconnects (such as 2-100 amp disconnects as described), then no. And you can't just add them together either.

[ROBERT YOUNG]

Only if ... IF ... they were in series (such as a 150 amp main in a panel).

If there are multiple disconnects (such as 2-100 amp disconnects as described), then no. And you can't just add them together either.
I concur. Do not add.
Which in this case, 2 separate feeds and service equipment, leaves the rating of the electrical service at 100 amp, as per equipment rating, not real measured electrical service rating that is typically/usually 400 amp, 120/240 V.

As to your 600 V. question, typo for that post.
I will explain when I get back from work.

Best as always, Jerry!
Looks like South Eastern US will be hunkering down to bad weather once again.
Prayers go out to everyone!
Keep safe.

[Jerry Peck]

Which in this case, 2 separate feeds and service equipment, leaves the rating of the electrical service at 100 amp, as per equipment rating, not real measured electrical service rating that is typically/usually 400 amp, 120/240 V.

How do you get 2 100 amp disconnects equals a 100 amp service?

I keep trying to explain it, but I am not getting what you are not getting, so I am not explaining it correctly - which means I need to first know how you are getting 100 amp?

[Jerry Peck]

With that assumption, being a 3-wire feeder ... there are two basic solutions: 1) replace the feeder if not in conduit; 2) pull in a grounding conductor if in conduit ... and if the conduit is sized to allow for the grounding conductor ... otherwise see 1).

Clarification on 2) above.

If the conduit is metallic ... the conduit may ... may (probably is/was) ... be being used as the grounding conductor (the 4th conductor) - just verify that the metallic conduit has continuity from end to end and has grounding bushings where needed, and then do not bond the neutral to ground.

If the conduit is PVC or there is no continuity through a metallic conduit, then 2) above stands.

[ROBERT YOUNG]

How do you get 2 100 amp disconnects equals a 100 amp service?

I keep trying to explain it, but I am not getting what you are not getting, so I am not explaining it correctly - which means I need to first know how you are getting 100 amp?

Likely your are explaining it correctly. I will review it slowly.

What I am explaining is that; during a home inspection, "home inspectors' rate", or I am use to writing it that way, and please tell me if there is a flaw, the main disconnects rating is used as the service ampacity gauge.

Take a 125 amp max disconnect. 125 amp is the service rating that home can service safely, or safely service. The OCP, over current protection, will not safely handle added ampacity.
The service size is likely 400 amp, 120/240 V. off the feed to the SEC, but the home is rated at 125 amp. for the sake of rating a home's electrical service.

Looking forward to your thoughts.

[Jerry Peck]

What I am explaining is that; during a home inspection, "home inspectors' rate", or I am use to writing it that way, and please tell me if there is a flaw, the main disconnects rating is used as the service ampacity gauge.

That is correct ... however, "when possible" should be added to 'home inspectors provide service size rating'.

When it is not possible (and many times it is not, such as split bus panels and multiple main panels, then all the home inspector can do is state what is present.


Take a 125 amp max disconnect. 125 amp is the service rating that home can service safely, or safely service. The OCP, over current protection, will not safely handle added ampacity.

Not totally correct, put in theory it is close to correct. A 125 amp main service disconnect should not trip at 125 amps, and it should take quite a while to trip at 130 amps, but should not take much time at all to trip at 5,000 amp.


The service size is likely 400 amp, 120/240 V. off the feed to the SEC, but the home is rated at 125 amp. for the sake of rating a home's electrical service.

Not sure where you are getting the 400 amp from? The standard residential service is 120/240 volt, with a minimum service size for dwelling units of 100 amps, with a 'common' (typical) service of between 125 amp and 200 amps, with some having larger services. I have inspected houses with 800 amp services, and I recall one was a 1200 amp service - I think, it was a number of years ago so I'm not positive on its size rating.

[ROBERT YOUNG]

That is correct ... however, "when possible" should be added to 'home inspectors provide service size rating'.

Thanks.


When it is not possible (and many times it is not, such as split bus panels and multiple main panels, then all the home inspector can do is state what is present.

Don't run into split bus panels often. I will try to remember that. Thanks.


Not totally correct, put in theory it is close to correct. A 125 amp main service disconnect should not trip at 125 amps, and it should take quite a while to trip at 130 amps, but should not take much time at all to trip at 5,000 amp.

Close is always good in horseshoes, grenades and, dancing:D


Not sure where you are getting the 400 amp from? The standard residential service is 120/240 volt, with a minimum service size for dwelling units of 100 amps, with a 'common' (typical) service of between 125 amp and 200 amps, with some having larger services. I have inspected houses with 800 amp services, and I recall one was a 1200 amp service - I think, it was a number of years ago so I'm not positive on its size rating.

I forget the literature I read that stated, 400 amp/ 4 AWG, is a typical residential service.
As well Jerry, I maybe/might be confused. I will look into it further.

Thanks for your replies.

[Jerry Peck]

Don't run into split bus panels often. I will try to remember that.

The main part of that was the other part about multiple mains.


I forget the literature I read that stated, 400 amp/ 4 AWG, is a typical residential service.
As well Jerry, I maybe/might be confused. I will look into it further.

Robert, I suspect you are thinking of 100 amp/4 AWG.

[ROBERT YOUNG]

The main part of that was the other part about multiple mains.



Robert, I suspect you are thinking of 100 amp /4 AWG.

Typo.
4/0 copper, 200amp, actually 230.

[ROBERT YOUNG]

Robert, I forgot to ask about the above in my other post: 600 volt? That was one of what I think were typos, but I forgot to ask about ti.
I remembered.:bounce:

SER Cable and SEU Cable's.

SER and SEU. SE service entrance cable, I trend to, writely or wrong, refer to than as the service entrance cables as the SEC, but will refer to them as SER and SEU when identified in the future, have/has various uses, but can most often be found being used to convey power from the service drop to the meter base and from the meter base to the distribution panelboard.

SER and SEU cable can be used in all applications where SE cable is permitted. If a temperature does not exceed 90 degrees C, SER can be used in dry or wet locations. The voltage rating of SER and SEU cable is 600 volts.

Home that helps, Jerry.

Sorry it took me so long to answer your questions. Hopefully repeating typo's will diminish over time.

[Jerry Peck]

The voltage rating of SER and SEU cable is 600 volts.

Basically speaking ALL conductors will have a minimum insulation voltage rating of 600 volts for line voltage conductors, ever low voltage conductors, as I recall, have a 600 volt rating.

Thank you for clarifying where the 600 volt came from ... I was stumped on that one.

[ROBERT YOUNG]

Basically speaking ALL conductors will have a minimum insulation voltage rating of 600 volts for line voltage conductors, ever low voltage conductors, as I recall, have a 600 volt rating.

Thank you for clarifying where the 600 volt came from ... I was stumped on that one.

My pleasure.

We can not know everything about everything at the drop of a dime.
As to your being stumped. My explanation narrative requires much polish.
Likely the way I explain what I do has something to do with your stumping.:)

You have been a very gracious and astute mentor.
Never been so happy. Truly.