Bonding Discontinuous Conduit

[quantum]

We have parallel conductors feeding an ATS. They are ran in RMC conduit, then transition to tray, then back to RMC. Each conduit has 3 phase conductors and a ground.

Do these bonding jumpers need to be the same size as the grounding conductor for each parallel run? I.E. sized based on the largest ungrounded conductor?

 

[Dennis Alwon]

Does this help

250.86 Other Conductor Enclosures and Raceways. Except
as permitted by 250.112(I), metal enclosures and raceways
for other than service conductors shall be connected
to the equipment grounding conductor.

 

[quantum]

These are paralleled service conductors from a Transformer to an ATS.

 

[infinity]

Is this a Delta system? If it's Wye I believe that you need a neutral along with the SEC's not a "ground".

 

[quantum]

Is this a Delta system? If it's Wye I believe that you need a neutral along with the SEC's not a "ground".

Delta

 

[quantum]

Anyone?

 

[quantum]

To restate, I'm wondering if the bonding jumpers between the discontinuous service conduits/raceways need to be sized the same size as the grounding conductor in the raceway.

 

[Smart $]

To restate, I'm wondering if the bonding jumpers between the discontinuous service conduits/raceways need to be sized the same size as the grounding conductor in the raceway.

Bonding jumpers are sized per 250.102(D), which directs you to 250.122... so same size as EGC.

 

[quantum]

Thanks. Is there specific place in the code that stipulates discontinuous sections of conduit/rgs must be bonded together?

 

[Smart $]

Thanks. Is there specific place in the code that stipulates discontinuous sections of conduit/rgs must be bonded together?

Not specifically.

Under Code, there is no such thing as a discontinuous run of raceway. They are required to be installed complete. So is a chase technically a violation???

You'll get various interpretations of required bonding of a raceway chases from cable tray to equipment enclosures. Some will say you have to put a bonding bushing on the cable tray end and jumper to the cable tray... but I say it is already bonded through the conduit-to-tray clamp and the conduit being pressed against the tray by same clamp... not to mention it is already bonded on the other end where it connects to the enclosure (using a bonding locknut if need be).

 

[quantum]

You cleared me up, thanks.

 

[earlydean]

Thanks. Is there specific place in the code that stipulates discontinuous sections of conduit/rgs must be bonded together?

check out 392.60(C) for cable tray to conduit
also 250.96, and 250.102