3 phase motor

Mike Poole:

Thank you; it's good to know some of the cost of a VFD is offset by energy saving.

I was told that a single phase 3/4 hp motor would be equalled by a three phase 1/2 hp motor, because of the smother power delivery. Being a mechanical Engineer, rather than an Electrical one, I accepted what I was told.

My lathe would have come with a 2 hp single phase motor, but I opted for a VFD with a 1.5 hp three phase. In sixteen years, I have yet to manage to stall it! Belt slip, yes, but stall motor, NO

Howard

John Haine and John Flefcher 1. I will send you both PMs. Regards, Lynne

The 2007 EU Directive isn't designed to annoy Model Engineers, it's one of several measures being taken to deal with a gathering international storm. The USA acted first in 1992, but the rationale behind legislation of this type is to reduce the impact of rising energy costs as oil depletes. The negative effects of Climate Change and Pollution matter too!

"Based on U.S. Department of Energy data, it is estimated that the National Electrical Manufacturers Association (NEMA) premium-efficiency motor program would save 5.8 terawatts of electricity and prevent the release of nearly 80 million metric tons of carbon into the atmosphere over the next ten years. This is equivalent to keeping 16 million cars off the road.

Roughly 30 million new electric motors are sold each year for industrial purposes. Some 300 million motors are in use in industry, infrastructure and large buildings. These electric motors are responsible for 40% of global electricity used to drive pumps, fans, compressors and other mechanical traction equipment. "

VFD's aren't only handy for turning single phase domestic mains into 3-phase. These days 3-phase to 3-phase VFD's are likely fitted in any new 3-phase motor installation. Their purpose is to save money by matching motors better to their loads over a wide duty range. Busy motors benefit most obviously, think Lift Motors in tall buildings rather than home workshop tools. The VFD usually pays for itself within 3 years.

Dave

SOD:

Good to know and interesting that the country normally cast as the villain of the piece was first in the field.

Where's your quote from, please?