Temporary Emergency Power Generators

Q: We are going to have temporary generators onsite for two months that we will use during our construction project to replace the main power distribution gear for our bed tower, installing new substation and distribution gear. During the time we will have 10 shutdowns from 4 hours to 12 hours at a time. We will be on the regular emergency power generators and ATS’s normally and only on the temporary units for the shutdowns. This affects normal critical and life safety circuits. Do we have to do monthly generator, and ATS transfers on the temporary units or would the shut downs count for testing? And for annunciation, we are planning to have the generators manned anytime they are in operation with no other temporary remote annunciation. Is this permissible?

A: These are all good questions, and I can provide you with answers on how I would approach this, but ultimately you need to talk with your state, local, and accreditation AHJs in order to get their opinions. Their opinions count and mine does not.

But since you asked, the accreditation organizations already allow an actual emergency event when the generators operate to count as one of the monthly load tests, provided the emergency event meets all of the requirements for a monthly load test. Therefore, I do not see any difference if the temporary generators operate or the regular emergency generators operate during an emergency event. So, I would say you still need to conduct monthly load tests on the generators (normal and temporary units), but an emergency event can count as one of the monthly load tests if it meets all of the requirements for a monthly load test.

I would think an ILSM on the annunciation issue should be sufficient, rather than running a temporary annunciation panel.