UPS sizing for compressors
UPS sizing for compressors
(OP)
A 0.8 kW compressor is to be supplied by an online UPS, the LRC is about 6 x In, i.e. 27.3 A @ 220 V.
Strictly speaking is to use the LRC to size the UPS, will be a 6 kVA unit to ensure that no overload/excessive VD occurs during starting.
Does the inverter allow any overload for a short time?
if so, less than 6 kVA UPS may be sufficient in this case, not sure about how to calculate the VD in this case as the internal impedance of the UPS isn't known.
Any ideas?
Strictly speaking is to use the LRC to size the UPS, will be a 6 kVA unit to ensure that no overload/excessive VD occurs during starting.
Does the inverter allow any overload for a short time?
if so, less than 6 kVA UPS may be sufficient in this case, not sure about how to calculate the VD in this case as the internal impedance of the UPS isn't known.
Any ideas?





RE: UPS sizing for compressors
Mike Halloran
Pembroke Pines, FL, USA
RE: UPS sizing for compressors
RE: UPS sizing for compressors
Mike Halloran
Pembroke Pines, FL, USA
RE: UPS sizing for compressors
If this is a 1-phase compressor it will almost certainly be a cap start, cap run type to meet the starting torque requirements of the load. Capacitors on a UPS output are not a smart idea. Find another way.
RE: UPS sizing for compressors
RE: UPS sizing for compressors
RE: UPS sizing for compressors
RE: UPS sizing for compressors
Mike Halloran
Pembroke Pines, FL, USA
RE: UPS sizing for compressors
Maybe with a suitable compressed air reservoir to carry the load during switch-over.
Jay Maechtlen
http://www.laserpubs.com/techcomm
RE: UPS sizing for compressors
Scotty is absolutely correct, large enough receiver tank, generator and transfer switch is the only practical way to go.
RE: UPS sizing for compressors
RE: UPS sizing for compressors
Mike Halloran
Pembroke Pines, FL, USA