Hi Stephen,
I note that you call the motor single phase. There is a very good chance of an industrial stand Myford having an industrial voltage motor – 3 phase, rather than single and requiring a 3phase converter. If its single, what sort of switch gear? My 1-phase M. has a drum switch with wires to 4 terminals inside motor casing + of course, a green and yellow (earth) wire to casing.

Wiring post part 2.

TERMINAL BLOCK TO DEWHURST SWITCH:-

Black wire from block 3 to drum 3. Red from block 4 to drum 1. Black from block 5 to drum 5. Red from block 6 to drum 2. Black from block 7 to drum 7. Black fro block 8 to drum 6.

Wiring Pt 4

Drum terminals 4 & 8 not used.

Block terminals 1 & 2 not used, in diagram but use say 1 for earth connection, not shown on diagram. Ensure you have a complete run of green and yellow striped earth wire from mains lead to block to motor casing, securely screwed-up tight. Also ensure that stand and lathe also connected. Beware, if you use cork washers under motor bolts to deaden vibration, you need to earth actual lathe, just in case….

Manual says "N.B. When a push button starter, with or without isolator, is fitted, the supply should be connected to it (or to the isolator), NOT to the terminal block."

Standard recommendation is to use a no-volt isolator for on/off and drum switch for merely reversing the motor.

As I dont have an isolator and just use the 3-pin socket switch, I cannot help with wiring in an isolator.

If you want, I will try to scan and send diagram to you. If the above connections fail to effect a reversal, you need to swap a pair of like wires to the motor, say A1 and A2 or T2 and T3.

If in any doubt obtain assistance of a qualified electrician as I cannot accept any responsibility for the previous posts.

Stephen,

I have put a wiring diagram for single-phase Industrial stand in my albums. This was originally a large (Imperial equivalent to A3) sheet so ahd to be reduced.

Got it from Myford years ago.

Have an Industrial stand wired for single phase but would have to open it up to check the wiring, can't do that just now as can't get at it!

The wiring diagrams from the "normal" manuals will not help, they are for external switchgear only.

I'll try and put it here:

Edited By Robbo on 09/12/2013 10:09:16

I too have the Industrial Stand wired for 3-phase and intend to use a Single Phase motor with the aid of the Single Phase wiring diagram A7966 from Myford. I see two issues : firstly the Santon Rotary Switch SR127 which is needed for single phase reversing is not standard and no longer available, but this is solvable because Santon rotary switches are modular in design and dismantlable such that one can easily make up one's own single phase reversing rotary switch from Santon parts reorganised. Secondly, the standard 3 phase Crabtree circuit breaker has a 380-420v coil inside and my question if anyone can help please is is it necessary , possible, and practical to change the coil to a 220-240v for domestic single phase usage? The Myford A7966 does not address this coil voltage issue so is that an error or does it in fact not matter? Furthermore , I can get no information on this Crabtree circuit breaker from Myford and wonder if anyone knows what the model is – all I can see on the casing is "J.A.C." and below that "C.B." and below that "2". If this breaker can be used, does anyone know what the adjustable "Full Load Motor Amps" needs to be set to (choices are 1, 1.25, 1.5, 1.75, 2) as these amps seem very low unless one is supposed to read the figures multiplied by a factor of 10. Many thanks to anyone who can help. Adam

To Adam with his Crabtree circuit breaker( which I think will be a contactor) I don't think Crabtree are still around any more,but it was normal to be able to change over coils in the past. However, in some cases the coils can be modified so that it will operate on 240 volts, by carefully removing about a third of the turns of fine wire. The coils are impregnated with varnish and some need warming otherwise the wire breaks and the end is hard to find. If the coil former is bakalite type material it can be put in warm oven or over the lathe light, becareful with modern plastic as it soon melts and distorts. Measure the coil resistance then remove turns until you have a resistance of 57% of what you had initially. Assemble the contactor and give it a test, a trcky job but it can be done.Ted

Hi Ted, Here is a photo , there are more in my album that you can view. What exactly is this big coil contactor (?) block on the right then, that has L1, L2, L3 inputs an A1, B1, C1 outputs, anyone?? Thanks, Adam

Hi Stephen,

I have just joined the forum.

Are you on the way to a solution or are you still looking?

I converted an industrial stand from 3 phase to single in 2011.

The Myford factory electrician told me I had to replace the Santon rotary switch with a rather expensive and ugly one from RS. This solution did not provide no voltage release.

I didn't want to change the external appearance of the front panel, so I did it by replacing the contactor. Worked our fairly inexpensive I think, doesn't load the Santon switch much and provides NVR.

I will add a wiring diagram if I can get "Albums" to work!

Hi Robert, I see your wiring diagram with the RS contactor and RS overload relay in your album. I too want to keep the appearance of the panel authentic and use the same buttons (I think the modern DOL plastic controller boxes detract greatly from the beauty of the old Myford). Very many thanks indeed. £40 (£48 incl vat) for the pair at RS is not bad but I will hunt around online for equivalent items used this w/e and will let you know what I come up with. Great help thanks. Adam,

Thanks Ted. The cheapest 230v single phase DOL starter I found on Ebay was Clarke £37 incl P&P but maybe Robert's RS package at £48 is neater and better and also reusable for 3 phase 240v in future if needed. Not looking to splurge on an inverter and 3-phase motor currently thankyou! Adam