2 Speed Motor Overloads

[donaldschexnaider]

Replacing a set of 2 speed motor starters. The motors are two speed one winding (2S1W) motors. In the high speed the low speed motor T leads are shorted.
Question is the placement of the overloads specifically on the low speed leads. Should the low speed overloads see the current of the low speed leads while in high speed?
This is strictly in question as to where to pick off for the shorting of the low speed leads.

 

[ScottyUK]

If you google Dahlander starter schematic you get plenty of hits. This one shows the overload placement quite clearly in the top right corner:

http://www.practicalmachinist.com/v...-s-contactor-schematics-dahlander-diagram.jpg

K1 is the fast contactor, K2 is the slow contactor.

 

[donaldschexnaider]

Yes there are a ton of these diagrams and schematics across the internet. None of them really approach the reasoning of the lo speed overloads while in the hi speed operation.

 

[ScottyUK]

Look at the current paths - no current can pass through the low speed overload relay when the fast (K1) and shorting (K3) contactors are closed and the low speed contactor is open. Am I mis-understanding your question?

 

[LionelHutz]

The answer is no.