Differences

This shows you the differences between two versions of the page.

--- systems:apc [2016/08/17 19:25] – [How to cold start and brain dead Smart-UPS] superwizard
+++ systems:apc [2020/09/18 01:46] (current) – superwizard
@@ Line 1: / Line 1: @@
+====== APC UPS Info ======
+{{http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=1497|APC RESET}}
+^ Load^ APC^ Watts |
+|{{leftThermometerMeaning.png|}}| Smart UPS 750 | 50% = about 340 Watts |
+{{APCResetMicrocomputer.png|}}
+====== Calculate needed capacity ======
+From: http://www.company7.com/library/C7_upscalc.html
+<code>
+UPS Capacity Ratings the UPS is typically rated by Volt Amps (VA), this is the maximum number of
+Volts * Amps it can deliver; note VA rating is not the same as the current draw (usually expressed
+in Watts) of the equipment. Some but not all UPS's can continue to deliver power to attached devices
+even if the VA rating of the UPS is exceeded, but a UPS can not provide power above their VA rating
+when the primary AC power fails. If you miscalculate the requirements and drain a UPS to beyond its
+capacity then you risk shortening the service life of the UPS's batteries and worse.
+To determine the suitable UPS capacity manually first calculate the required amps and time in hours or portion of an hour (AH), then calculate:
+calculate battery power of the UPS (ie battery voltage) * AH
+time = (inverter efficiency * battery volt * AH)/load in watts)
+So if:
+. the UPS is a 1500 VA unit then this likely relies on healthy 12 volt 12.5 amp hour battery
+. if the telescope mount's power supply draws 200 watts at 120v (1.7 Amp), the dome motor
+draws 373 watts at 120 volt (3.1 Amp), and we want 20 minutes operating time (.33 hour) then
+. time in hours = (0.9 * 12 * 33)/(200+373)*.33 OR 356.4/189.1 = 1.9 hours
+</code>
 ====== How to cold start and brain dead Smart-UPS ======