Recommendation? speed control for 3 phase motor

[SV-97]

Sadly its the price of being self proclaimed leaders of the free world.

Sorry but I just can't get behind that sentence. The US started its grid way later than most of Europe and I wouldn't exactly say distributing power with only one phase has any advantages; I'd actually argue the contrary is the case. Especially since you're running lower voltages overall.

 

[Stacy E. Apelt - Bladesmith]

Not to derail this thread more, but:
The main reasons for the power type in the US was distribution. First it was AC vs DC, then single vs three phase and 120 vs 240 volts. We had far greater distances to deal with. 240 volts became the standard line voltage for most use. 120 is just center tapped 240 referenced to ground. Using the ground as one leg saved millions in copper wiring at a time when a million dollars was a fortune. Since homes have no reason to need three phase power, or voltages above 240V, it isn't run to them or the cluster style neighborhoods that sprung up all over the USA. It is rare that a home has any need for a motor over three HP, and heating and cooling can easily be handled with single phase loads. The USA has the highest degree of home ownership, thus there is more single phase use. Since there is no need for it, there is no need to spend the money running more lined down the poles. ASspower now moves underground, more three phase may get run into residential areas.
Industry, businesses, apartment/condo housing, etc. in the USA all have three phase because it delivers more power to one place. The big transformer on the back side of these buildings changes it into single phase for most use, and keeps three phase to run the big motors for equipment and heating/cooling.

 

[kuraki]

Sorry but I just can't get behind that sentence. The US started its grid way later than most of Europe and I wouldn't exactly say distributing power with only one phase has any advantages; I'd actually argue the contrary is the case. Especially since you're running lower voltages overall.

He was being sarcastic, America is stupid and Europe is awesome remember?

 

[Lieblad]

Los Angeles
both single and 3 ph
I don't know what voltage I have, but I'm guessing 110 and 220

Its fairly obvious 120V is available, but the 3Ø voltage available is anybodys guess.
But, guess I will.
120V is the phase voltage of a 208V wye.
But, 120V is also obtained by centertap ”B” phase of a 240V delta. (”Hi-leg delta”)
Its fairly safe to believe 208v or 240V is your available 3Ø voltage.
A step further,,
I dunno common practice in L.A., but 240V delta is uncommon in my area in buildings newer than 50 years or so.
Good luck for you. 3Ø power !!

 

[Ken H>]

Yep, the ONLY way to tell what your 3Ø voltage is would be to measure it using a volt meter. Measure phase A to B, A to C, and B to C so you'll know what they are. Is 460 voltage used in commercial bldgs much for 3Ø? Industry uses 460 (or 480) voltage almost totally.

 

[kuraki]

It depends on the age of the building. Our building at work, used to be multiple buildings from various decades before combining them all under one roof. The older areas are 240. The newer is all 480.

208 or 200/400 is rather uncommon in the US, at least here. I have to set a transformer almost every time we buy a Japanese or Euro machine.