Industrial Control Panel

[blues]

I have a vendor supplied control panel with a single main disconnect switch within the control panel. This panel is fed from a remote MCC OCPD on the site. The vendor is requesting a fused disconnect adjacent to their control panel. I believe NEC 409.21 will allow the main switch within the control panel serve as the disconnect. Would you agree?

Thanks

Dan

 

[infinity]

The integral disconnect switch is NEC complaint. According to the NEC does the ICP even require a disconnecting means?

 

[nhee2]

could the fuses be required in order to maintain an SCCR rating on the panel?

 

[jim dungar]

could the fuses be required in order to maintain an SCCR rating on the panel?

Or even to comply with LOTO point external to the equipment for NFPA70E?

 

[drktmplr12]

Or even to comply with LOTO point external to the equipment for NFPA70E?

the breaker at the MCC can serve as the safety disconnect provided there are provisions for LOTO on the operating handle. having a local disconnect is a matter of preference in most cases.

curious that a control panel vendor wouldn't simply provide a circuit breaker or fused disconnect as the integral disconnecting means.. they are likely trying to pass the cost to someone else..

i was never a fan of requiring that someone else provide the OCPD for my panel.

 

[drktmplr12]

could the fuses be required in order to maintain an SCCR rating on the panel?

quite possibly..the control panel would then need to be marked that the upstream OCPD must be replaced with fuses or OCPD of the same exact type.

an external fused disconnect would also lower the arc flash incident energy available inside the control panel-if it needs to be worked on while energized. IMO if the panel does not need to be worked on live, there is no good reason to have external fused disconnect adjacent to the panel..

 

[jim dungar]

the breaker at the MCC can serve as the safety disconnect provided there are provisions for LOTO on the operating handle. having a local disconnect is a matter of preference in most cases.

Vendor may have been required to provide an installation that was below a specific arc flash incident energy, to comply with the customer's implementation of NFPA70E. The vendor could have chosen to have a local external overcurrent protective device to accomplish this goal. This location might be above and beyond the LOTO point that satisfies OSHA.

I know of at least one vendor doing this exact scenario. But they were doing it for the benefit of their service technicians.