NFPA 72 requires a battery test be run including removal of the main power supply, waiting the full-length standby time, then activating the fire alarm system for the full alarm time. After the alarm time, the battery voltage is required to be tested.
What is the pass/fail mark for the battery voltage?
In theory, if the battery output still has 20.4 V, then the last appliance on a NAC circuit would still get a minimum of 16 V and everything still functions correctly. I just can't seem to find a code reference whether 20.4 V is the correct voltage to use (where a voltage reading below 20.4 V fails the battery).
Thanks in advance.
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