Motor Specification Query

Consumption wired as Star or Delta ?

AWEM

Hi Andrew,

I'd have expected star and Delta powers to be the same. the two current ratings are in the correct ratio for star & delta I also note that the product of the voltage & current in either star or delta is roughly the P2 figure which suggests this is the VA rating which should be greater than the true power consumed.

Hmm!

Confused of Romsey

Bob

message

Star and delta power will vary if the voltage stays the same. This is why big motors use star/delta starters

AWEM

True but I don't think this is the meaning in this instance as the ratio of the powers quoted is not the same as the ratio of the currents quoted.

I have just seen elsewhere a saw of the same brand with Power in and Power out quoted in similar proportions.

If i end up buying the thing I'll just have to make some measurement to satisfy my curiosity!

Bob

My guess is that you're right. Rating plates for stuff like welding sets uses that convention,of a suffix (1) for input and (2) for output.

OK, so it's inefficient

Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Bob,

I think you're missing out the famous square root of 3 in your calculations. Taking this into account, the apparent power will be about 2.8 kVA in either case. I think it's possible that the lower power figure is a continuous rating, and the higher figure an intermittent rating.

Best wishes,

Chris