Winding Pitch Code

Hi.

The pitch "code" is the number of slots spanned (or linked) by a single stator coil. Full pitch would mean that the coil links 180 electrical degrees but it is common to short-pitch or "short-chord" coils for harmonic-reduction purposes. For this reason, your "2/3 - 6" reference probably means that the stator coils are short-chorded by 2/3 and that equates to 6 slots (slots 1 to 7 as armature winders would refer to it) being linked or spanned by each stator coil.

If my assumption is correct this means that your generator full pitch is 9 slots. I don't believe the "12 wires" is relevant in this respect because this most likely refers to the number of conductors or turns in this case - in each stator coil. However, if your objective (and question here) is related to rewinding the generator stator then be careful to check that there is only a single strand per turn and that the "12 wires" referrred to equates to the actual number of turns per coil. You should easily be able to check this by inspecting even a damaged existing coil's ingoing or outgoing leads - for a single strand or several parallel strands. If it's a small unit, a single strand / conductor is most likely.

To check my assumption of 9 slots being full-pitch - you can do the following: If your generator is a 4 pole unit (1800 rev/min for 60 Hz or 1500 rev/min for 50 Hz) then the total number of slots will be 4 times 9 = 36, which is possible if it is a small unit. If it is an 8 pole unit (900 rev/min for 60 Hz or 750 rev/min for 50 Hz) then the total number of slots will be 8 times 9 = 72, and so on.

I hope this helps. Good luck!

Rob Melaia

Hello melaia,

Take a look at this page below:

http://www.soarpower.com/pdf/GEP400-2_4page_english.pdf .

Look under Alternator Tech Spec. It gives this detail as mentioned in the OP's request and also says is has 12 wires. It seems you are correct my friend.

bb

Thanks babybear!

Good luck zhoucwj!

Rob.