[BabyPeanut]

The ECM Motor Story

[NeoPeasant]

$this->bbcode_second_pass_quote('BabyPeanut', '[')url=http://www.nailor.com/pdf/ECM_1.pdf]The ECM Motor Story[/url]

[ChumpusRex]

Electric motors, especially large commercial units, are huge power consumers. Electric motors account for about 65% of US electricity demand.

In general, again, especially for commercial motors, the capital cost is negligable compared to the running cost. The lifetime cost ratio for typical industrial/commercial motors is between about 100 and 300. I'd expect that energy ratio, may in fact be even greater (given the low efficiency of conversion from primary energy to electricity).

This means, it may be cost effective to pay 100% extra for a motor which is 1% more efficient!

I accept that this design brings increased complexity - but solid state electronics are very reliable - and have been used for a couple of decades for specialist industrial equipment and in domestic appliances. Indeed, the higher efficiency and lower heat generation could potentially improve reliability.

[Starvid]

$this->bbcode_second_pass_quote('ChumpusRex', 'E')lectric motors, especially large commercial units, are huge power consumers. Electric motors account for about 65% of US electricity demand.

[WisJim]

$this->bbcode_second_pass_quote('ChumpusRex', '
')I accept that this design brings increased complexity - but solid state electronics are very reliable - and have been used for a couple of decades for specialist industrial equipment and in domestic appliances. Indeed, the higher efficiency and lower heat generation could potentially improve reliability.

[oiless]

Umm...nah.
I have AC induction motors, 30, 50, 100, 150, 200 horsepower, that have been running for years and years, producing work from electricity, with reasonable efficiency, in some of the most adverse, dusty, wet, and temperature challenged conditions you could imagine. They are simple and reliable.
These won't sell for general industrial use.

[BabyPeanut]

$this->bbcode_second_pass_quote('NeoPeasant', 'O')k, it's a real efficient fan motor. Looks rather costly and complicated compared to a dumb fan motor.

[BabyPeanut]

$this->bbcode_second_pass_quote('WisJim', 'I') have seen them with electronics destroyed by lightning in the area that had absolutely no affect on computers, phone equip, etc., in the same building running off the same electrical service.

[WisJim]

$this->bbcode_second_pass_quote('BabyPeanut', '')$this->bbcode_second_pass_quote('WisJim', 'I') have seen them with electronics destroyed by lightning in the area that had absolutely no affect on computers, phone equip, etc., in the same building running off the same electrical service.

[small_steps]

True,

The power electronics in drives in all forms are the weakness in this tech. The front end (rectifier) can get toasted by overvoltages, and overcurrents when recovering from voltage sags. The caps have limited lifetimes, and the rest of the circuit (esp the igbts) suffer from thermal cycling. The actual motor itself is a fairly robust piece of equipment, but then again, the winding insulation is the weak spot there.

This series was introduced in 1985, so it is a relatively mature technology, and there have been multiple interations on this. What the next step in HVAC seems to be is the use of drives on the compressors of the refrigeration cycle. They have (seemingly) been successfully used in the fan/pump end for quite some time, and with the introduction of new materials, and the cost reductions in PMs in recent years, these drives will likely see inroads in a variety of products, even without the increased energy costs that we are seeing. That is that the manufacturing cost of these permanent magnet machines is very competitive versus the induction machine, and when the machine is driving a varying process, the cost of the drive for the PM machine will be less than the cost of a drive for the IM, largely due to the current requirement which is due to poorer power factor of the IM, as well as reduced rotor losses.