Natural Gas is the most common fuel for small to mid sized life safety generators in this area.

A few times we have had to remove diesel sets and replace them with natural gas sets.

This was necessitated because the storage of diesel fuel near wet lands around here is a major problem.

The NEC provides an exception to the on site fuel requirement.

Exception: Where acceptable to the authority having jurisdiction, the use of other than on-site fuels shall be permitted where there is a low probability of a simultaneous failure of both the off-site fuel delivery system and power from the outside electrical utility company.

I have never heard of the gas being shut down and I guess the AHJ has not either. [Linked Image]

Bob Badger
Construction & Maintenance Electrician