Generator Pitch
Generator Pitch
(OP)
Does anyone know of an easy way to determine (in the field)a generators pitch. In other words How can I figure out what the pitch of an existing generator so I know what to order to put on line with an older unit for paralleling?






RE: Generator Pitch
RE: Generator Pitch
Normally generator pitches are 5/6th.
RE: Generator Pitch
RE: Generator Pitch
The alternator also have the sr. no. or winding arrangement no. stamped (engraved) in its body.
RE: Generator Pitch
RE: Generator Pitch
RE: Generator Pitch
Assuming that we deal with a three-phase generator and a multiple turn coil winding:
First count the number of stator slots and divide this number by the number of poles. Then you've got the number of slots per pole (number of slot pitches per pole pitch). This number in most (but not all) cases is a fractional number.
Then determine the number of slot pitches between top layer of a coil and bottom layer of the same coil. This number always is a whole number, of course.
Divide the second number by the first number and you get the winding pitch. For large hydro generators winding pitches can vary between about 0.80 and 0.95. The higher this pitch number is the higher the voltage induced into this coil will be.
Wolf
WWW.HYDROPOWER-CONSULT.COM
RE: Generator Pitch
RE: Generator Pitch
Then would come the hard part: If you're lucky, pull up a datasheet on a 5/6th pitch generator and it will let you know how much attenuation there is for the 3rd, 5th, 7th.. etc harmonic. Compare to the results you get on your spectrum analyzer.
I think that the better approach involved looking at the windings of the generator if you can, as Wolf mentioned. I don't know how difficult this might be based on actually being able to get to this area of the generator and make sense of it.
The BEST option, of course, is to get the nameplate information, and then find the manufacturer's datasheet information on what the pitch is.
RE: Generator Pitch