Running paralleled MC Cables that requires EGC adjustment

[PP26]

The electrical contractor is running (6) sets of 600KCMIL AL. MC cables protected by a 1200A OCPD. The total cable ampacity is rated for 2040 amps, however, the equipment grounding conductor (EGC) of the MC cable is only 250KCMIL AL. After applying 250.122(B), the minimum EGC should be at least 400KCMIL AL.
I would love to hear recommendations based on experience or solution on how to resolve this issue without making modifications on the electrical distribution design.

Thank you in advance.

 

[infinity]

Common problem when using MC cable for parallel conductors. There isn't much that can be done except maybe for breaking down the sets into smaller feeders where the 250 kcmil EGC will be the proper size.

 

[tom baker]

This is a common question with no alternative to 250.122B.
You can search previous posts here for more background

 

[infinity]

This is an area where electricians need to be schooled on the major disadvantage of using parallel MC cable feeders. I see this quite often when the EC's will value engineer the feeders and opt for MC cable over EMT to save money and end up with a non-code compliant installation.

 

[LarryFine]

I thought somebody made MC with larger EGCs.

 

[don_resqcapt19]

You can get custom cable, but there will probably be a 10,000 foot minimum order.
You maybe able to install the MC in cable tray and run a single full sized EGC in the tray along with the MC cables. 250.122(F)(1)(a) seems to permit that, but you have to read a bit into it.
The other options would be single conductors in cable tray, cable bus, bus duct, or conduit and wire.

 

[electrofelon]

I thought somebody made MC with larger EGCs.

Not sure the quantity the op is running, but might be able to get a special custom run. Pre-covid I would say no big deal they'd probably do it no problem, we have done it, but custom runs of stuff have been really difficult lately. Worth checking though.

Only other thing I can think of is Photoshop the spec sheet to show 400 MCM EGC if the inspector asks

 

[tom baker]

This is an area where electricians need to be schooled on the major disadvantage of using parallel MC cable feeders. I see this quite often when the EC's will value engineer the feeders and opt for MC cable over EMT to save money and end up with a non-code compliant installation.

And with EMT No EGC is required.