Thanks Drew. I wasn't mixing my concepts, I was falsely believing APC SmartUPS series and above were all Online rather than "Line-Interactive" (APC's terminology) therefore conditioning circuitry was not necessary. So much for me thinking the server at home had an online supply!
So ... Online UPS = conditioning not needed due to design Line Interactive = must have good conditioning circuits/do your homework/looks like most APC models fit here. -dbc. -----Original Message----- From: Drew Gibson [mailto:[email protected]] Sent: April-07-09 5:15 PM To: David Cook Cc: [email protected] Subject: Re: [biz] UPS: power conditioned I think you might be mixing two different UPS concepts here. This can be a contentious subject but if I may be allowed to simplify.... The best UPSs (eg larger and more expensive, say >8KVA) are online, full-time. They constantly convert the AC in to DC, feed it to the batteries and then draw the load as DC and convert it back to AC to supply the load device. Most of the of UPSs the small to mid-size, affordable UPSs are only fully online when the mains power fails and power from the batteries is required. There is a short (very short) interval during a power failure as the UPS switches the supply from the AC input to battery. Otherwise the AC is fed straight through to the load device. In the first case, power conditioning is done by default as the power is always being processed and "conditioned". This is the best type in terms of protecting your computers, but hard on the budget. In the second case, power conditioning has to be added. Most reasonable devices will, in fact, condition the power to some extent. They will moderate high input voltages, boost sags in the voltage (by drawing from battery) and suppress spikes and surges. This type is a little less capable in terms of protecting equipment but the lower price makes up for that and more. APC do make both types as do Tripp-Lite and others. Since phone systems are expected to operate during power outages for much longer than regular servers, I would recommend the second type due to cost. I would oversize the UPS (they are usually sized by power rather than runtime) to get a longer runtime. Both APC and Tripp-Lite make units that can have external batteries added for additional runtime. The last one I spec'd would run the Asterisk server and the VoIP switches for 3-4 hours. (APC 2200XL rackmount, if I remember rightly) regards, Drew David Cook wrote: > I believe all APC upses qualify in that regard. Conditioning should refer to > methods of ensuring that transients and other oddities from the power line > never reach the equipment plugged into them. > > My understanding is that all APC upses (and most other "good" upses) are of > the variety that the line power only serves to charge the batteries - > nothing more. The batteries subsequently feed constant power into the > inverters which create the 110VAC (hopefully a sine wave) to power the > equipment. Therefore at no time are the products plugged into the UPS ever > connected to the line current and therefore not subject to stuff outside > affecting your equipment. > > The analogy used to explain it to me was filling a bucket (batteries) with > water with a fixed size hole in the bottom (VA rating of the UPS). As long > as some volume of water is retained in the bucket, you can fill the bucket > evenly or sporadically but the flow rate out the hole remains the same. > > If my understanding of this is full of crap, please let me know :-) > > -dbc > > -----Original Message----- > From: Frank Bax [mailto:[email protected]] > Sent: April-07-09 3:00 PM > To: [email protected] > Subject: [biz] UPS: power conditioned > > In the Asterisk book from O'Reilly; it says "Make sure your UPS is power > conditioned. If it doesn't say exactly that, it isn't." > > http://astbook.asteriskdocs.org/en/2nd_Edition/asterisk-book-html-chunk/aste > risk-CHP-2-SECT-2.html#asterisk-CHP-2-SECT-2.1 > > I don't see this wording on any UPS devices from APC; do they sell one? > If not, who does? > > Frank > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
