Supply side bonding jumper

[hhsting]

Can supply side bonding jumper be screw or it has to be wire? I don’t see where in code it says this.

 

[infinity]

How would you use a screw for a SSBJ?

 

[texie]

How would you use a screw for a SSBJ?

You just ask for a long and flexible screw with treads on the end.

 

[electrofelon]

It would be quite rare to be in a situation where one could use a screw as a SSBJ, although there is no definition of a SSBJ in the NEC (unless they've added one after 2014?). Say one had a neutral terminal bar attached to a service pull box or trough. Could the screw holding that bar to the box be considered an SSBJ?

 

[augie47]

It would be quite rare to be in a situation where one could use a screw as a SSBJ, although there is no definition of a SSBJ in the NEC (unless they've added one after 2014?). Say one had a neutral terminal bar attached to a service pull box or trough. Could the screw holding that bar to the box be considered an SSBJ?

"250.2 SSBJ A conductor................................."

 

[kwired]

It would be quite rare to be in a situation where one could use a screw as a SSBJ, although there is no definition of a SSBJ in the NEC (unless they've added one after 2014?). Say one had a neutral terminal bar attached to a service pull box or trough. Could the screw holding that bar to the box be considered an SSBJ?

I'd say if designed and listed that way yes.

Midwest terminal boxes we use often on farms have terminals mounted in insulating blocks. They come with a copper bonding jumper, probably about a 2 AWG solid copper conductor in most 200 amp versions and a lug bolted to the box to land it in. That lug is only tapped into the box with a 10-32 screw though. Never seen one burn off, but have seen 1/4 bond screws in 200 amp panelboard neutral bus burn off where tapped into enclosure, probably because they were not properly tightened.

 

[electrofelon]

"250.2 SSBJ A conductor................................."

Ah thanks. I always forget there are more definitions at the beginning of some articles.

 

[hhsting]

It would be quite rare to be in a situation where one could use a screw as a SSBJ, although there is no definition of a SSBJ in the NEC (unless they've added one after 2014?). Say one had a neutral terminal bar attached to a service pull box or trough. Could the screw holding that bar to the box be considered an SSBJ?

I have neutral terminal in splice box line side of service trough. The trough feeds multiple disconnect enclosures downstream. Grounding electrode system would be at this splice box neutral bar. Neutral bar needs to be bonded to enclosure. Dont follow would a screw holding bar considered SSBJ?


Sent from my iPhone using Tapatalk

 

[electrofelon]

I'd say if designed and listed that way yes.

Midwest terminal boxes we use often on farms have terminals mounted in insulating blocks. They come with a copper bonding jumper, probably about a 2 AWG solid copper conductor in most 200 amp versions and a lug bolted to the box to land it in. That lug is only tapped into the box with a 10-32 screw though. Never seen one burn off, but have seen 1/4 bond screws in 200 amp panelboard neutral bus burn off where tapped into enclosure, probably because they were not properly tightened.

It was a while ago, but I am pretty sure I did 1000 amp CT cabinet that had an isolated neutral bar, and a screw could be used to bond it to the cabinet like in a typical load center. I would say that is a SSBJ per Augies definition.

 

[hhsting]

How about NEC 2014 section 250.102(A) would that apply for supply side bonding jumper?


Sent from my iPhone using Tapatalk

 

[kwired]

It was a while ago, but I am pretty sure I did 1000 amp CT cabinet that had an isolated neutral bar, and a screw could be used to bond it to the cabinet like in a typical load center. I would say that is a SSBJ per Augies definition.

And that screw was probably designed and tested for the application, you can't just put any screw in there. Just like the screws that are used to bond panelboard neutral assemblies.

If the grounded bus is factory bolted directly to the enclosure it is probably already considered bonded. If you are installing your own lug, bar, etc, you probably need to remove paint where applied, and possibly even put a screw/bolt all the way through with a nut on back side - then the lug/bar contact with the enclosure is your bonding and the bolt is just securing it.

 

[electrofelon]

And that screw was probably designed and tested for the application, you can't just put any screw in there. Just like the screws that are used to bond panelboard neutral assemblies.

But that section the OP just mentioned, 250.102, says bonding jumper can be a screw. I guess they say "screw" they are referring to "Factory" bonding jumpers by this? I dont see any way to size a screw in 250.102(C)

 

[LarryFine]

Say one had a neutral terminal bar attached to a service pull box or trough. Could the screw holding that bar to the box be considered an SSBJ?

I'd say the bar itself is.

 

[electrofelon]

I'd say the bar itself is.

....Or, note 250.92(B)(1) sends you to 250.8. 250.8(A)(2) is "terminal bars". I agree its a bit nitpicky to call the screws or bolts holding the terminal bar to the cabinet SSBJ's

 

[texie]

I have neutral terminal in splice box line side of service trough. The trough feeds multiple disconnect enclosures downstream. Grounding electrode system would be at this splice box neutral bar. Neutral bar needs to be bonded to enclosure. Dont follow would a screw holding bar considered SSBJ?


Sent from my iPhone using Tapatalk

Don't make this anymore complicated than needed. Just bolt a multi port lug with enough ports for your neutrals and GEC directly to the wireway. If you need more ports you can stack another multi port lug on top. They just need to all be stacked with one bolt attaching them so you are not using the enclosure as a conductor. No bonding jumper needed.

 

[hhsting]

Don't make this anymore complicated than needed. Just bolt a multi port lug with enough ports for your neutrals and GEC directly to the wireway. If you need more ports you can stack another multi port lug on top. They just need to all be stacked with one bolt attaching them so you are not using the enclosure as a conductor. No bonding jumper needed.

Don’t the enclosure which is metal and on line side of service disco need to be bonded to neutral which is my grounded conductor?


Sent from my iPhone using Tapatalk

 

[texie]

Don’t the enclosure which is metal and on line side of service disco need to be bonded to neutral which is my grounded conductor?


Sent from my iPhone using Tapatalk

Just bolt the lug(s) directly to the enclosure. The neutral is now bonded to the enclosure.

 

[don_resqcapt19]

I can't think of any application where the supply side bonding jumper could be a screw. Are you really asking about a system bonding jumper?