Air Handler Shutdown

Q. I would like to know if you can articulate the EC 5.40 elements of performance on the following matter. Is it a true statement that in order to verify that the shut down device(s) works you must shut the air handler down. I don’t see this statement contained in EC5.40 items # 1 and 15. I also looked up NFPA 90A and it doesn’t reference that the unit must be shut down in order to determine if the automatic shutdown devices work. Can you please expand on this matter? I referenced item # 6.4.2 an 6.4.4.2.1. in NFPA 90A.

A. The NFPA code section reference reads "all automatic shutdown devices shall be tested annually". A reasonable person would consider that to include smoke detectors, relays and other controls. To me, it does not include HVAC fan motors. Be that as it may, the way we wire life safety devices around here you would have to jump something out electrically to avoid shutting down the HVAC- in other words if you have a "hand" position on a motor control circuit, it will be overriden by life safety signals. By jumping it out, you are not completely testing the controls. You could have a welded relay contact and never know it, for example, if you jump that relay out to keep the fan online.

Later in that code book, the acceptance testing section states "Acceptance tests of fire protection devices in air-conditioning and ventilating systems shall, as far as practicable, be performed under normal operating conditions."

To me, that is the best way to test something - "end to end" is what I call it. You would be amazed what can be inadvertently overlooked when you do anything less than a "real" test. As much of a PITA as a real test can be, it is usually worth doing.

Hope this helps.

John M. Kramer PE