i have a customer who wants to back up power using a UPS system for a few hours without using a generator. They would need 125a 240v 1 phase. i have only seen and installed UPS or power bay with 24v rectifiers with 240v power supply. i have been asked to install a 240 dc to 240v ac. Any thoughts on a system that can do that??
240v UPS
- Thread starter MBLES
- Start date
- Status
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Liebert or APC might have something but you'll run into two gotchas- most UPS that size are 3-phase and that's a really long run time; 30Kva/hour is a lot of batteries for that size UPS. If nothing else that's a fair amount physical space and you need to make sure the charger is up to charging that big a stack while also supplying the load.
You might be better off breaking the load across two or three individual UPSs.
Why no generator?
You might be better off breaking the load across two or three individual UPSs.
Why no generator?
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
A LOT of batteries...
Non-electrical people often have no way to conceptualize what it means to say "125A for a few hours". Just to give you an idea, a Liebert 30kVA UPS with internal batteries is maybe 15 minutes of hold-up time. To get 2 hours, you would likely need their largest external battery rack. The UPS with the internal batteries is 24W x 40D x 79H and weighs 678 lbs, an external battery unit that MIGHT be capable of 2 hours of backup is another cabinet, 35W x 40D x 79H and another 1678 lbs! So you are looking at well over a ton of equipment here...
And as noted, this is 3 phase only.
Oh, and you are looking at somewhere in the neighborhood of $50,000
Non-electrical people often have no way to conceptualize what it means to say "125A for a few hours". Just to give you an idea, a Liebert 30kVA UPS with internal batteries is maybe 15 minutes of hold-up time. To get 2 hours, you would likely need their largest external battery rack. The UPS with the internal batteries is 24W x 40D x 79H and weighs 678 lbs, an external battery unit that MIGHT be capable of 2 hours of backup is another cabinet, 35W x 40D x 79H and another 1678 lbs! So you are looking at well over a ton of equipment here...
And as noted, this is 3 phase only.
Oh, and you are looking at somewhere in the neighborhood of $50,000
- Status