There are three-phase 2-pole motor with 18 slots with single-layer winding and span 1-8.
Do any of rewinders had such a case and what is the internal connection diagram?
Standard single-layer windings are made with step 1-10 in two variants: pic1 and pic2.
Does the diagram in pic3 is good?
Zlatkodo
Answering your question, This an old way to rewinding electric motors, for two poles you need 6 groups connected by pole methods in this case a 18 slots - single layer winding is not possible you will need to use two coils per group, the span can´t be 1-8 the right span is 8-10.
Other important consideration is the 1-10 span coil will have the half of turns and the 1-8 span coil the full of turns.I am attaching you a diagram.
Hi, Carlos,
Thanks for your answer.
Your diagram is known to me and it is most common in practice, but according to the informations that I often get, step 1-8 (single-layer) is also often used. Example: Siemens motor 0.35 kW, 3000 rpm, 1Y, 220/440, model 2AA3032 and many others. I suppose it could be some sort of interspersed winding.
Zlatkodo
About your interspersed winding (IW)comment this practice is most recommmended in large motors to minimize adverse effects of harmonics and some manufacturers uses too to make possible the winding connection for two and four circuits. Note: In a standard two pole winding you have a maximum of two circuits.
Winding design speaking also you can get a single layer 18 slots-2 pole winding with three groups connected in consecuent poles, the two options are 3 groups of 3 coils per group: Span: 1-10 (Lap) and Span 8-10-12 (Concentric).
Take a look to the attachment for winding diagrams.
