Table saw motor wiring

[brianmoooore]

I have read some single phase motors have start/run windings with different resistances so that may account for the values i got. However, all the single phase motors i find reference to have two windings.

I've thought earlier that the wiring diagram of that motor makes much more sense if the winding on the yellow wires is deleted, and the resistance ratio between the other two is approximately what I would expect.
Marconi could well be onto a winner with his idea of a feedback winding to control the NV switch. Makes sense, and uses up a couple more of the surfeit of terminals on that switch.

 

[Lucien Nunes]

I've only just skimmed the thread for the first time but surely the two yellow leads with 0.14Ω between them would be a thermal overload cutout in series with the neutral end of the hold coil of the NVR switch?

 

[marconi]

There are 4 terminal and 5 terminal NVR switches for single phase motor applications such as your FERM table saw. In both the 4 and 5 terminal switch the hold on coil is 230V ac mains voltage.

There is no way that the motor has a 230V ac sense coil with only a resistance of 0.14 Ohms - the wire would have to be too thick and thus the winding too bulky to fit inside the motor. The device between the yellow wires with a resistance of 0.14 is - as Lucien keenly and helpfully observes a switch - a thermal cut out switch. I feel a Captain Mainwaring moment - 'I was wondering when someone would spot that'. My musings 3-5 were fanciful - only 1 and 2 apply.

The form, fit, function for the switch in the image you posted is met by a KJD18 with 5 terminals but do check dimensions:

ChaRLes 250V 15A Kjd18 Switch 5 Pin No-Voltage Release Switch Plastic : Amazon.co.uk: DIY & Tools - https://www.amazon.co.uk/ChaRLes-Switch-No-Voltage-Release-Plastic/dp/B07VDR3J3G/ref=sr_1_8?dchild=1&keywords=kjd18&qid=1626145243&sr=8-8#descriptionAndDetails

See attachment - ignore unused contacts 5 and 6 of image - I could only find a picture for a KJD18 7 pin for 3 phase 400V ac.

 

[polaroid]

Awesome thank you all, Lucien for the penny drop moment and a special thanks to Marconi for your time!

I'll report back when it's sorted.

 

[marconi]

You may need to buy some spade terminals and crimper to make the connections to the switch.

Amazon.co.uk : Spade Terminals - https://www.amazon.co.uk/Spade-Terminals/b?ie=UTF8&node=10256656031

 

[polaroid]

You may need to buy some spade terminals and crimper to make the connections to the switch.

Amazon.co.uk : Spade Terminals - https://www.amazon.co.uk/Spade-Terminals/b?ie=UTF8&node=10256656031

Yeah, I'm putting a new enclosure on it too with some decent glands due to the previous water ingress. Should be good for a few more years after!