3 phase resistance calculation

[bill1983]

i spoke to a guy from RS today and he confirmed what many of you have said, that there is o formula to calculate the resistance. he did tell me that the resistance is a result of the motor design and that the motor is designed to rotate at a certain speed which is determined by the work the motor has to do. i don't understand it fully yet, but i will report back on this forum, hopefully before the end of the week, with a better explanation.
thanks again for your interest

[prtadko]

i am going to try and answer the origanal question.

you are wanting to do a quick calc to check a motor winding. on the side of any motor there is a data plate ( as i am sure you know). the info you need is motor KW, V, A and cos.

formula W (kw/1000) = 1.732 * VL * IL * cos

The motor KW rating is the culmative total of all three balanced windings. so motor kw/3 is approx the power rating of 1 winding. ANS/Vp = Ip. then do Vp/Ip = winding Z ohms.

in reality its a bit more complicated than that, but in the middle of the night on a wet and windy roof, it should give you a good idea.

hope that helps

sparky matt

[Peter_1]

but i will report back on this forum, hopefully before the end of the week, with a better explanation...

Still waiting since more than 2.5 years now