Main OCPD

[mhellx]

Hello there,

I have designed a panel for water injection skid.

I already made it and I have a main MCCB(480VAC, 60Hz, 3P) for the protection of main bus.
Connected to the main bus are the MCCBS for 250HP motors(VFD drive), transformer for lightings and C.O., Skid Heater, Panel Aircon.

I gave my design to the client and his asking if I can take off the main breaker to make it cheaper. They will just connect directly to the main bus. They will just adjust the client source breakers for our ratings.

From client side LV switchgear the feeder length is 306meters to our skid's Panel.

Does the NEC permits this kind of design? If yes, what are the additional provision for this kind of design. For example if we need to do some maintenance, de-energizing is very difficult since the client's breaker is far from the Skid's Panel.

If the NEC prohibit this kind of installation in what articles can I refer to to show to the client that it is prohibited by the code.

Thanks.

Rommell

 

[ptonsparky]

Try 230.70 and 230.71(A).

More than 6 and you need a main.

 

[ron]

I will guess that your panel is downstream of the service entrance and is fed by a regular
feeder. If so, no main is required.
It sounds like any disconnects required by article 430 are addressed by the distribution breakers in the panel that will remain.

 

[ptonsparky]

Is this a separate building or structure? 225.31 thru 225.33.

 

[mhellx]

Thanks for the replies I will read all the articles youve mention.

I just want to add some details.

@ptonsparky

The location of the skid's panel is within the skid (field)

The location of the clients source LV Switchgear is on electrical room.