If you hear an alarm in the counting house, go to the Si Monitor computer. There should be a window describing the alarm problem.
Hit the "close" button in the alarm window, and the alarm will stop sounding for 2 minutes.
If the alarm persists, and is clearly related to power failure in the tunnel and/or counting house, do not panic (there should be plenty of UPS time, as indicated in the Si Monitor screen), but ramp down and turn off any Bias power supplies that might be on, and switch OFF the corresponding FEC power supplies.