400 amp breaker feeding a 400 amp mlo panel and a double bucket 200 amp panel

[Jabieder87]

I have a 400 amp breaker feeding a 400 amp mlo panel. Is it legal to feed a double bucket 200 amp panel out of the lugs on the 400 amp panel? The lugs are rated for two conductors. If it is legal is it legal to use 3/0 conductors or do I have to remain sized for the 400 amps to the 200 amp panel? The double bucket panels are feed through panels. Thanks

 

[GoldDigger]

If the lugs allow that additional connection and the termination at the 200A panel has a main breaker, and the run in between meets one or another set of feeder tap rules the smallervwire might be OK. You cannot have the sub be MLO with a limit on the sum of the load breakers. The tap conductors must end on a main breaker.

 

[electrofelon]

What is a double bucket panel? Is this a two gang meter socket with output breakers?

 

[infinity]

I have a 400 amp breaker feeding a 400 amp mlo panel. Is it legal to feed a double bucket 200 amp panel out of the lugs on the 400 amp panel? The lugs are rated for two conductors. If it is legal is it legal to use 3/0 conductors or do I have to remain sized for the 400 amps to the 200 amp panel? The double bucket panels are feed through panels. Thanks

Yes, as Digger stated you would need to comply with the tap rule in 240.21. In this case you would comply specifically with the 25' rule, which requires among other things that your tap conductors be at least 1/3 the ampacity of the 400 amp OPCD so #3/0 would work.