OT: New PC!

Will · #1 January 12th, 2006, 02:07 AM

If you go to a site like NewEgg, they will tell you the VA rating, and the wattage it is designed for. I have an APC BE725BB, which is a 725VA, 450W UPS (I have a 450W PSU). It came with a little monitor utility that lets you set timers when on the backup, so you can have your computer automatically shut down after some time, or hibernate.

Plus, you can use it for general purpose stuff. During the big blackout in LA this fall, I took it down to the lobby, and plugged the radio we have down there into it to figure out what happened (some dude from PG&E cut a wire he wasn't supposed to, and the entire basin got its power cut).

Baron Munchausen · #2 January 12th, 2006, 12:04 PM

Quote:

Will said:
If you go to a site like NewEgg, they will tell you the VA rating, and the wattage it is designed for. I have an APC BE725BB, which is a 725VA, 450W UPS (I have a 450W PSU). It came with a little monitor utility that lets you set timers when on the backup, so you can have your computer automatically shut down after some time, or hibernate.

Plus, you can use it for general purpose stuff. During the big blackout in LA this fall, I took it down to the lobby, and plugged the radio we have down there into it to figure out what happened (some dude from PG&E cut a wire he wasn't supposed to, and the entire basin got its power cut).

According to references I have, a 'volt-ampere' is one volt at one amp, and so equivalent to one watt. Therefore, the VA rating should be exactly the same as the wattage it can support. I wonder what they are really describing if they don't rate the VA and watts as the same?

AgentZero · #3 January 12th, 2006, 02:06 PM

Well, this one CyberPower Office Tower 750VA UPS Line Interactive RS-232 seems to be the most affordable UPS that could handle my 680W PSU. I don't know much about CyberPower, does anyone know what sort of name they have?

Fyron · #4 January 12th, 2006, 03:15 PM

Quote:

UPS�s are given volt-amp (VA) ratings, which is the maximum apparent power the unit can deliver to the load. UPS�s may also have a wattage (W) rating, which is not the same as the VA rating, and refers to the actual power consumption of your connected equipment.

From bottom of:

http://www.cyberpowersystems.com/electricity.asp

The "VA" rating is not what you need to be so concerned with, but rather the direct wattage rating. VA is more concerned with charge capacity (in a roundabout way), whereas W measure is maximum instantaneous power draw from the battery. Of course, higher VA means longer operation after power loss. VA vs. W ratings are used in this way very commonly for electric devices.

Cyber Power's site lists all the information for their UPSes, unlike that store site AZ linked to.

Baron Munchausen · #5 January 12th, 2006, 05:11 PM

Ouch...

http://www.apcmedia.com/salestools/S...NQYF_R0_EN.pdf

It looks like the actual wattage is closer to 60 percent of the VA. That means my 850 VA UPS is only 'adequate' for my load, and AgentZero is in fact going to need a 1000 VA or larger UPS!

AgentZero · #6 January 13th, 2006, 08:37 AM

Good grief. A 1000VA UPS starts at close to eur400. Now, correct me if I'm wrong, but it seems to me that the whole VA-Watts thing is basically a matter of how long the unit can last in the event of power loss, right? Or does it affect something else as well?
In the seven years I've been living in Dublin, there's only been one blackout I know of, but it was localized and didn't affect me. So I'm not too worries about blackouts, so much as power surges and the like. Given that, I'm wondering if I'd be better off buying just a surge protector, since the likliehood of a blackout is very low.

Baron Munchausen · #7 January 13th, 2006, 04:12 PM

Quote:

AgentZero said:
Good grief. A 1000VA UPS starts at close to eur400. Now, correct me if I'm wrong, but it seems to me that the whole VA-Watts thing is basically a matter of how long the unit can last in the event of power loss, right? Or does it affect something else as well?
In the seven years I've been living in Dublin, there's only been one blackout I know of, but it was localized and didn't affect me. So I'm not too worries about blackouts, so much as power surges and the like. Given that, I'm wondering if I'd be better off buying just a surge protector, since the likliehood of a blackout is very low.

A little bit more will get you a 'line conditioner' -- a surge protector plus a transformer that steps low voltage up a little bit. This additional protection is a good thing to have. Utilities also have 'drops' in voltage as well as surges. This is included in a UPS these days, so you're actually getting three different systems in a UPS: surge protection, low voltage protection, and blackout protection.

You might also try searching for used equipment. After all, it's not like a UPS built now is dramatically better than a UPS built 5 years ago.

I know you can buy reconditioned UPSes from used computer dealers here in the US. Dunno about Ireland or the EU in general (voltage is standardized throughout the EU, right?)

http://www.usedcomputer.com/classifi...Classified.asp

http://www.refurbdepot.com/index.cfm

Fyron · #8 January 13th, 2006, 04:26 PM

Quote:

AgentZero said:
Good grief. A 1000VA UPS starts at close to eur400. Now, correct me if I'm wrong, but it seems to me that the whole VA-Watts thing is basically a matter of how long the unit can last in the event of power loss, right? Or does it affect something else as well?

The amount of total charge is only the VA rating. W rating is how much power it delivers an a time, so you need a big, beefy one that can deliver 600W or whatever the powe drain was. This does not require a 1000 VA UPS, but rather a 600W one. Maybe 650W to be safe and cover the monitor.

I see absolutely no hard correlation between W and VA ratings on Cyber Power's UPSes. Some are VA = 2 W, some are VA = 1.4 W, etc.