UPSes also switch over from mains supply to battery when the mains frequency alters either way from 50Hz, and depending on whether the UPS is an online or standby unit well depend on it's tolerance to frequency excursions. Standby units are not very tolerant. Apart from the fact that the mains frequency can typically drop to 49.5 Hz and go up to 50.5 Hz, other factors include ripple control, for controlling things like Controlled Loads (Water Heating), Day/Night Tariff control (Night Store Heating), Street lights, which is basically done by injecting another frequency in the mains supply to cause the ripple relays to change over and that typically happens around this time. How often was the UPS changing over ? On Sun, 2005-10-02 at 23:01 +1300, Kyle Carter wrote:
Just an inquisitive question. My UPS seemed to go mental last night/this morning (around midnight Sat Oct 1st) flicking between battery and mains repeatedly for a few hours.. But no flickering lights or anything..
Im wondering if anyone else had something similar? Im assuming it may have been the power company doing something weird re: daylight savings?
Kyle Carter
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