How to size a UPS for 60 hp, 480 3 ph motor?
How to size a UPS for 60 hp, 480 3 ph motor?
(OP)
Been asked to determine a budget cost to provide a UPS feed motor as listed above. Never sized a unit of this size before so not sure where to start. Any suggestions / thoughts would be nice.





RE: How to size a UPS for 60 hp, 480 3 ph motor?
You need to get the UPS manufacturer's recommendation. At minimum consider a solit state reduced voltage starter or a VFD, this will help a great deal to keep the UPS size within limits.
RE: How to size a UPS for 60 hp, 480 3 ph motor?
RE: How to size a UPS for 60 hp, 480 3 ph motor?
I'd talk it over with two or three UPS vendors. And write your spec to explain **precisely** what the UPS is required to do. Try to shift as much of the risk to the supplier as possible. If you just order a UPS and it doesn't work, it will be your problem. If you write a performance spec, the UPS supplier will be responsible for making it work.
RE: How to size a UPS for 60 hp, 480 3 ph motor?
You also need to backup any controls so the motor doesn't get stopped by the start input when the power goes out.
RE: How to size a UPS for 60 hp, 480 3 ph motor?
Some manufacturers may be able to supply a battery back-up system as described by LionelHutz above.
Third part accessory suppliers may also be able to supply a battery back-up system. One is http://www.bonitron.com/. There may be others.
RE: How to size a UPS for 60 hp, 480 3 ph motor?
If it's a VFD you could possibly set back the motor's speed 10% or so to extend the battery run.
100A @ 600V
(100)6V batteries deep cycles.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: How to size a UPS for 60 hp, 480 3 ph motor?
RE: How to size a UPS for 60 hp, 480 3 ph motor?
All great suggestions - just wish it would be a standard option from a drive manufacture.
RE: How to size a UPS for 60 hp, 480 3 ph motor?
I once came up with engineering on a list of options available for a VFD manufacturer using a lot of the custom projects I had worked on prior to coming to work for them. They offered them and nobody bought a single one, mostly because their version needed to be slightly different than mine anyway, which made it an engineered special anyway.
http:/www.jraef.com
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: How to size a UPS for 60 hp, 480 3 ph motor?