Minnesota Chapter IAEI Q&A

submitted by Sam Sampson, IAEI

Q:

My inspector told me I cannot install a 100-amp main-lug-only sub-panel in a detached garage even though it is fed from a 60-amp breaker at the main panel in the house. I’ve seen this done before and don’t believe it’s a code violation.

A:

First and foremost, remember that no matter what the question, the inspector is always correct. That said, you could gently remind the inspector that while NEC Section 408.36 requires that all panelboards have overcurrent protection, that protection is not required to be an integral part of the panelboard. The overcurrent protection cannot exceed the rating of the panelboard, so providing 60-amp overcurrent protection for a 100-amp rated panelboard is acceptable. Of course, the 60-amp feeder must be adequate for the load in the garage to comply with 215.3.

Remember that an MLO panelboard in a detached structure without a separate disconnecting means at that building would need to be rated a suitable for use as service equipment, be located nearest the point of entrance and would be limited to 6 circuits.