SSBJ disagreemt

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dbehounek

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I have run into a problem with installation of a supply side bonding jumper in a Main service disconnect. I have a CB enclosure that is rated for use as service equipment. My inspector has failed the installation stating that I am required to have a "factory supplied" bonding jumper. This particular unit does not have provision for the green bonding screw that goes through the grounded (neutral) bus/lug kit to bond the enclosure. I sized the bonding jumper as a wire using the NEC table 250.101(C)(1) and ran the jumper from a spare lug of the neutral to a terminal that is screwed to the enclosure via tapped machine screw (1/4 x 20). The terminal bus is for the equipment ground and earth ground. I do not see a code violation here, but the ispector still fails it. Where am I wrong and what article is being sited to validate the failure of the inspection?
 
The inspector is using 110.3(B). A bit picky but that is his perogative. It is hard to believe the equipment is service rated and did not come with provision to bond the neutral to the can.

If the equipment states Only Suitable as Service Equipment" then the neutral would be bonded to can without any jumpers. Not sure what you have there
 
dbehounek said:
I have run into a problem with installation of a supply side bonding jumper in a Main service disconnect. I have a CB enclosure that is rated for use as service equipment. My inspector has failed the installation stating that I am required to have a "factory supplied" bonding jumper. This particular unit does not have provision for the green bonding screw that goes through the grounded (neutral) bus/lug kit to bond the enclosure. I sized the bonding jumper as a wire using the NEC table 250.101(C)(1) and ran the jumper from a spare lug of the neutral to a terminal that is screwed to the enclosure via tapped machine screw (1/4 x 20). The terminal bus is for the equipment ground and earth ground. I do not see a code violation here, but the ispector still fails it. Where am I wrong and what article is being sited to validate the failure of the inspection?
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I agree 100% with all of Mr. Alwons statements and will add some additional thoughts of my own.

1) You described this thread as a SSBJ Disagreement...but in reality you have a Main Bonding Jumper Disagreement...Terminology is KEY.

2) You stated that you reference the sizing to Table 250.101(C)(1)..but I believe you mean Table 250.102(C)(1)...Correct?

3) Taking the fact that as Mr. Alwon also stated, typically a SUSE Rated panel would have the provision already in place to make the case-to-neutral connection as part of the equipment so validate with the manufacturer that this is indeed a SUSE rated enclosure and that they give options for meeting the requirements of Section 250.28.

Provided you have meet all the installation perimeters of Section 250.28 and assuming your Service Enclosure is SUSE Rated, by verifying the literature with the panel manufacturer...then refer to all the steps in Section 250.28 with your inspector and show them that you meet the material requirements and clearly item (C) gives you guidance on the permitted attachment methods...

But you have to establish from the manufacturer that the equipment is SUSE rated first....then unless the manufacturer expresses otherwise follow the methods in Section 250.8 and sizing in Section 250.102(C)(1) and explain it to the inspector accordingly.

FYI- Did you request from the inspector the code references?...that is always helpful and in many jurisdictions it's required or part of policy to provide the references to all rejected inspections.
 
What size breaker ? I ask as sometimes you MBJ is a strap and not a screw but you probably already know that.
If it is SUSE you might check with your supplier to obtain a Jumper / screw. It is not uncommon for the jumper to get misplaced and often they are easily obtained from the supplier/manufacturer.
 
I personally don't think tapping a hole in the can sheet metal is equivalent to a manufacturer's connection point. All I have seen are thicker to engage more threads. As a utility inspector, I'd probably require a screw and nut arrangement with the paint sanded off. I also agree that if it's rated as service equipment, it should have a bonding provision. I don't think there's any Code requirement for a factory MBJ. How is the neutral/ground bus attached to the panel? Insulated standoffs or direct mount? If the incoming conduit is metal, what is it bonded to? A pic would be interesting....
 
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meternerd said:
I personally don't think tapping a hole in the can sheet metal is equivalent to a manufacturer's connection point. All I have seen are thicker to engage more threads. I also agree that if it's rated as service equipment, it should have a bonding provision. If you sanded the paint off and put a screw and nut arrangement for the lug, would that make him happy? How is the neutral/ground bus attached to the panel? Insulated standoffs or direct mount? If the incoming conduit is metal, what is it bonded to? A pic would be interesting....
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So you believe Section 250.8(A) is not adequate? So the panel enclosures that utilize a "green" screw are more adequate than a provision given in 250.8(A)(6) for example?

Again it is going to fall on the equipment....I know manufacturers who have said the provide one way but the choices in Section 250.28 is your choice as long as they are sized and installed properly...and then again one manufacturer thats supplies only the "Screw" option may say...this is the only option we provide or permit in our listing.....again depends on the manufacturer so they need to be asked in my opinion if the Inspector is not going to accept otherwise.
 
So the panel enclosures that utilize a "green" screw are more adequate than a provision given in 250.8(A)(6) for example?

There's no way a 1/4 20 screw in the sheet metal can is going to engage at least two threads. 10/32, maybe.
 
meternerd said:
So the panel enclosures that utilize a "green" screw are more adequate than a provision given in 250.8(A)(6) for example?

There's no way a 1/4 20 screw in the sheet metal can is going to engage at least two threads. 10/32, maybe.
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I did not talk sizes....I talked methods...

The user is not to try and replicate a GREEN screw in the case of one being missing. What simply using a different method to make the connections in accordance with the NEC and Section 250.8(A). In Section 250.28 is does not express otherwise...Clearly (C) provides for the uses within 250.8(A) to make the connections....I am not going to assume anything.....what I am going to say is they have to meet 250.8(A) and in the case of item (6)...they have to meet the provision.

I really did not comment on the 1/4 -20 because I believe he needs to contact the manufacturer and ask them for options if the equipment is SUSE rated...because something sounds missing here.
 
meternerd said:
... requirement for a factory MBJ...
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The UL Listing label is very important.
Suitable for Use as Service Entrance means there factory has provided the means, and methods, for a 'field connectable' MBJ.
Suitable Only for Use as Service Entrance means the factory has provide the MBJ, and it is not intended to be removed in the field.

To my knowledge, the NEC does not specifically address these terms.
 
jim dungar said:
The UL Listing label is very important.
Suitable for Use as Service Entrance means there factory has provided the means, and methods, for a 'field connectable' MBJ.
Suitable Only for Use as Service Entrance means the factory has provide the MBJ, and it is not intended to be removed in the field.
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I agree it should be one or the other.

To the OP, a photo of the nameplate would help.
 
I recently ordered a 400 amp 120/240 Main breaker panelboard from a local panel shop. Since it was going to be use for a completely off the grid service (PV and generator) I wasn't sure where the main main bonding jumper was going to be located. The PV and generator installation were by a different contractor but I wanted to supply the panel so the correct feeder breakers were installed. I told the panel shop I wanted the panel to be suitable for use a service entrance equipment. The panel came with a sticker saying it was Suitable for use a service entrance equipment but didn't come with a bonding jumper. The PV contractor installed a jumper wire between the neutral buss and EG buss.
 
clarifications

clarifications

So, to clarify, the circuit breaker enclosure is rated for up to 400A and has a 400A circuit breaker installed. The label from the manufacturer (GE) states suitable for use as service equipment, it did not come with a bonding screw or even have the provision to install one through the neutral bus to the can. There were , however, stamped out holes that could accept screws to mount a ground bar/terminal set up. The hole was stripped, so it was tapped out to a 1/4 x 20 hole and there are definitely two threads in contact (didn't have a 12x24 screw or would have used that instead). In 250.2 definition of SSBJ should apply to my installation.

(When researching possible solutions, I could not find a set up that was designed for the enclosure the would qualify as "factory supplied", but I did find an alternate one that I was able to install and get the inspector to buy off on it)
 
Correction

Correction

You are correct to say that I have a main bonding jumper as this is not a separately derived system and is actually a new service.
 
dbehounek said:
So, to clarify, the circuit breaker enclosure is rated for up to 400A and has a 400A circuit breaker installed. The label from the manufacturer (GE) states suitable for use as service equipment, it did not come with a bonding screw or even have the provision to install one through the neutral bus to the can. There were , however, stamped out holes that could accept screws to mount a ground bar/terminal set up. The hole was stripped, so it was tapped out to a 1/4 x 20 hole and there are definitely two threads in contact (didn't have a 12x24 screw or would have used that instead). In 250.2 definition of SSBJ should apply to my installation.

(When researching possible solutions, I could not find a set up that was designed for the enclosure the would qualify as "factory supplied", but I did find an alternate one that I was able to install and get the inspector to buy off on it)
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Where does it say that the bonding jumper must be factory supplied? Is his objection the tapped 1/4" hole? If so, clean off the paint and nut and bolt the lug right to the enclosure with a wire type main bonding jumper sized according to 250.66.
 
infinity said:
Where does it say that the bonding jumper must be factory supplied? Is his objection the tapped 1/4" hole? If so, clean off the paint and nut and bolt the lug right to the enclosure with a wire type main bonding jumper sized according to 250.66.
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We did that as well. The inspector stated it had to be factory supplied. It is listed as Suitable for use as Service equipment, but the only method provided was to install a lug and use a wire. I actually ran into this with the inspector once before. He required it to be factory supplied and so we ordered it from Siemens. They sent out two rated lugs and a note that said to refer to the NEC for proper sizing. What really had me irritated is the inspector told us that this is not the 1950's and we don't bond that way anymore....hmm...then why does the code still allow it????

We have since cleaned the paint from the can, still used the 14 x 20 tapped but also added the nut to assist in securing the bolt, installed a little different ground lug and still used the jumper wire that we had originally installed as well as installing a bonding lug for the neutral with the stupid little green screw. The inspector has passed it now. I am just trying to understand his logic around this. I know the AHJ can be the final say at any point, but just because he prefers a different method does not mean everyone has to agree with him.
 
dbehounek said:
We did that as well. The inspector stated it had to be factory supplied. It is listed as Suitable for use as Service equipment, but the only method provided was to install a lug and use a wire. I actually ran into this with the inspector once before. He required it to be factory supplied and so we ordered it from Siemens. They sent out two rated lugs and a note that said to refer to the NEC for proper sizing. What really had me irritated is the inspector told us that this is not the 1950's and we don't bond that way anymore....hmm...then why does the code still allow it????

We have since cleaned the paint from the can, still used the 14 x 20 tapped but also added the nut to assist in securing the bolt, installed a little different ground lug and still used the jumper wire that we had originally installed as well as installing a bonding lug for the neutral with the stupid little green screw. The inspector has passed it now. I am just trying to understand his logic around this. I know the AHJ can be the final say at any point, but just because he prefers a different method does not mean everyone has to agree with him.
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Having a nut is covered under 250.8(5) You won't get three full threads in the sheet metal thus you have to have the nut. Threading the sheet metal was not required.

If you look at the holes in a panel marked with a grounding symbol, you should see the metal is deformed enough to get three threads of a 10/32 threaded hole in it.
 
don_resqcapt19 said:
I would expect that is part of the listing requirement to be able to mark the equipment "suitable for use as service equipment".
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I'm curious whether that really is a listing requirement- does SUSE mean "we give you the jumper" which might not readily apply to large switchboards*, "there's a designated place to put the jumper", or "we tested under the fault conditions that a service might have".

*if all SUSE gear came with a jumper, why is there a section on sizing them? A quick read of 250.8 (in 2008) doesn't suggest that it must be mfg-supplied, only that there must be one. I don't have ready access to the UL docs.
 
It appears that I may be wrong about the listing requiring the main bonding jumper to be provided with equipment that is listed as "suitable for use as service equipment". I do have access to the UL document for "switchboards" and that does not require that the switchboard be provided with the main bonding jumper, but it does require that there be instructions as to how to install the main bonding jumper.
 
don_resqcapt19 said:
It appears that I may be wrong about the listing requiring the main bonding jumper to be provided with equipment that is listed as "suitable for use as service equipment". I do have access to the UL document for "switchboards" and that does not require that the switchboard be provided with the main bonding jumper, but it does require that there be instructions as to how to install the main bonding jumper.
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"This is how you install the thing we didn't supply" ??????? :D
 
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