Dahlander motor connection - Page 1
Forum section: electronics / general

author: nForce
author_rank: Frequent Contributor
timestamp: January 01, 2018, 02:25:55 pm
content: Hello,I am reading this article on wikipedia:https://en.wikipedia.org/wiki/Dahlander_pole_changing_motorHow do we count number of poles on the wiring diagram? Which has more poles, is it YY or D?

author: MrW0lf
author_rank: Frequent Contributor
timestamp: January 01, 2018, 06:28:35 pm
content: https://www.quora.com/What-is-the-electrical-circuit-diagram-for-pole-changing-speed-control-methodDahlander pole-changing circuit (speed control)https://www.achrnews.com/articles/84983-how-to-determine-speed-for-an-ac-induction-motorhttp://machineryequipmentonline.com/electric-equipment/consequent-pole-motorsthree-speed-consequent-pole-motors/QuoteSo Wiki statement is little incomplete:QuoteIn Wiki case D has 2x poles of YY, since it is specified that D is low speed.

author: nForce
author_rank: Frequent Contributor
timestamp: January 02, 2018, 06:26:36 pm
content: Sorry, but I am a beginner, so I don't understand something:Pole, stator winding and phase.We have three phases in our electrical system L1, L2, L3.So stator windings are also three, but we can have more poles for each winding. So how can you describe this diagram for a beginner? I know it's a ratio 2:1. But I still can't imagine poles on the diagram.

author: MrW0lf
author_rank: Frequent Contributor
timestamp: January 02, 2018, 07:31:32 pm
content: Dahlander patent:https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=DE&NR=98417C&KC=C&FT=D&ND=&DB=&locale=en_EP4-pole delta explained:4-pole field:

author: Yansi
author_rank: Super Contributor
timestamp: January 02, 2018, 07:40:01 pm
content: The last bottom right image with the three phase short circuit is supposed to be what?//EDIT: Where did the image go?

author: MrW0lf
author_rank: Frequent Contributor
timestamp: January 02, 2018, 07:41:47 pm
content: Quote from: Yansi on January 02, 2018, 07:40:01 pmImage did go away because it was confusingThis should be better:Edit: Since image is still somewhat crap looked further, found well done YT explanation:

author: nForce
author_rank: Frequent Contributor
timestamp: January 02, 2018, 09:09:57 pm
content: Well from this, I can say that every fourth tooth on the stator from the "video 4-pole field" is connected together;1.- North pole 2. - South pole 3. - North pole 4. - South pole.This group is one phase, we have three groups like this, so three phases.So then 12 stator winding (12 coils)?

author: nForce
author_rank: Frequent Contributor
timestamp: January 02, 2018, 10:47:51 pm
content: Ok, I think I know now;The reason why D has 2x more then YY is because we have 2 in series connected inductors. So one inductor can have 4,8,12... poles. 2*4 = 8, and 8*2 = 16 and so on...No matter how many poles we have it's always the ratio 1:2.Right?

author: nForce
author_rank: Frequent Contributor
timestamp: January 03, 2018, 03:03:13 pm
content: Quote from: nForce on January 02, 2018, 10:47:51 pmAm I right about it? And my posts before this one. Is it all correct?

author: MrW0lf
author_rank: Frequent Contributor
timestamp: January 06, 2018, 10:46:18 am
content: Dunno about "all" have not looked at this for long time. But physical poles indeed must allow 1:2 ratio. Even number of poles.