I can't give you any information specific to Myfords but my Boxford has a similar switch. When I bought it it was configured to switch a 3 phase motor but some of the contacts were all but burned out and it failed. However there were enough good bits in it to reconfigure and use to switch a VFD. If you can't figure out what goes where with a multimeter you may be able to work it out by dismantling it. One thing that may help is that not all of those terminals are necessarily going to connect to "in" or "out" wires – some may need to be ganged together with short pieces of wire.

William.

What make is your motor and can you identify which winding is the start and which is the run. As it says on the switch its a Santon, they are not easy to dismantle and reassemble, if you going to attempt to dismantle the switch do it in a large clear plastic bag, so that those little springs won't fly all over the place and get lost. I see on your picture there are 6 terminals which you need so you maybe lucky. I have an old Myford leaflet and it shows A1 is connected to one end of the start winding, the other end of that winding goes to one of the connection on the internal centrifugal switch, the other connection on the switch is connected to A2. F- is to the mains supply and so is F+. Run winding to a pair of unmarked pair of terminals either way round. Whilst that is a bit vague I hope might be useful. John

IF it is a santon single phase then the Myford hand book gives the following F- neutral, F+ live, A1 start winding, A2 start winding and the remaining 2 terminals are the run windings. The motor terminals very much depend on who and when the motor was made. If you have a brooks motor then it gets confusing as Sw A1 goes to Mtr Z!, Sw A2 goes to Mtr Z2 and Mtr A1 and A2 are the run windings ! Good Luck, Noel.

SOD 's diagram is only valid for a permanent magnet motor, which is not what the OP has. If reversing is not required then I'd put this switch aside and buy a motor starter with no volt release

Here is some information on a Santon switch that someone was using with a Myford. It may not be the same as the Santon switch that you have but you can meter out your switch to see if the contact layout is the same as the one in my notes.

This is from a thread that was probably around 10/03/16 (When I uploaded the picture to the forum.) or 29/09/14. (The date of the file on my computer.)

These are the notes that I uploaded to the thread,

Information on Santon switch which is sometimes fitted to Myford lathes

This is how I understand the switch works.

Forward B to 2, C to 1, A to 3

Reverse B to 2, C to 3, A to 1

I have been looking at the way the switch works. There must be 5 contact sets. Each contact set is on a layer of the switch. I will call the front layer layer

1. Terminals C, 3, and A are actually connected to 2 layers each. (You can see the metal connections from 2 adjacent layers bent together.) Terminal C

goes to layers 1 & 2. Terminal 3 goes to layers 2 & 3. Terminal A goes to layers 3 & 4. The contact that I expected to be closed in the for forward position

of the switch (Terminals 3 and A)

Layer 1 Terminals C (and 1 via a wire link) (Closed in forward.)
Layer 2 Terminals C & 3 (Closed in reverse.)
Layer 3 Terminals A & 3 (Closed in forward.)
Layer 4 Terminals A & 1 (Closed in reverse.)
Layer 5 Terminals 2 & B (Closed in forward & reverse.)

Wires from motor to switch

Start R

Start S

Run U1

Run U2

Santon reversing switch connections.

1 To motor start terminal (R ?)

2 Live in

3 To motor start terminal (S ?)

A Live in

B To motor run terminal (R ?)

C | Neutral in
| To motor run terminal (U1 ?)

Where the above connection shows start terminal it means the start winding in series with the centrifugal switch and start capacitor.

Les.

Edited By Les Jones 1 on 05/07/2022 20:16:39