What Are The Design Limitations of a Licensed Contractor?

[jar546]

I know this is a state-by-state and jurisdiction-by-jurisdiction answer, which is why I am posting it here on The Building Code Forum (TBCF). To hone in on more specific answers, I am using a specific code to see how you handle compliance. The waters will be rather muddy with this one.

NEC 240.12 Orderly Shutdown is the code section we will use, which reads:

Where an orderly shutdown is required to minimize the hazard(s) to personnel or equipment, a system of coordination based on the following two conditions shall be permitted:

• (1) Coordinated short-circuit protection
• (2) Overload indication based on monitoring systems or device

A further explanation would be that with coordinated overcurrent protection, the faulted or overloaded circuit is isolated by the selective operation of only the OCPD closest to the overcurrent condition. This selective operation prevents power loss to unaffected loads. Coordinated short-circuit protection automatically opens the circuit by localizing and de-energizing the faulted portion of the circuit, but an overload condition is not required to result in automatic opening of a protective device. Instead, an alarm can be used to warn of the overload condition, and remedial action can be taken.

In some circumstances, an orderly shutdown of a system or process is more critical to personnel and equipment safety than is the automatic operation of the OCPD in response to an overload. Examples of overcurrent protection with and without coordinated protection are illustrated in the following exhibit.



QUESTIONS

1. Who determines when an orderly shutdown is required?
2. Is an electrician qualified to make this decision?
3. When was the last time you did plan review and cited NEC 240.12?