Help with wiring please.......

[slim_boy_fat]

How far from perth are you?

Many miles...I'm 40 miles to the North of Inverness.

Coffee has helped, as it always seems to for @The_Yellow_Ardvark

Completely disconnected the Dewhurst and connected the motor 'as was' direct to the 240V supply and it runs as before, so panic over on that front. #phew

Is it possible to bugger up a Dewhurst switch? Logically it shouldn't be, but what do I know..... Don't understand where the flash/bang and magic smoke could come from...or why

I don't want to get involved with 3Ph with inverters so will keep going with what I have. Would I be best just forgetting the d/hurst, but since you currently [see what I did there ] have a similar setup on yours I can see no reason for mine not to work?

 

[rikrobson]

The dewhurst switch connected the middle pair of contacts to the two outer ones. So in off there is no connection. In forward the middle pair t and z are live and neutral. In reverse they are neutral and live.
The bang and smoke will be a short in the circuit so something is wrong.. it will all need metering out I'm afraid. If you were a bit nearer I could have popped up but you said getting on for 4 hours away. Can't do Inverness in under 2 hours any more with the pesky cameras.

 

[slim_boy_fat]

If you were a bit nearer I could have popped up but you said getting on for 4 hours away.

Aye, far too far, but the thought is greatly appreciated.

Possibly a faulty D/hurst switch? And is there an idiot's way of testing it?

 

[rikrobson]

Yup. The pairs 1 and 3 will buzz out when on. The middle pair will buzz out to either pair and will switch on direction. Maybe I'll make a video for you.

 

[eestibob]

Many miles...I'm 40 miles to the North of Inverness.

Coffee has helped, as it always seems to for @The_Yellow_Ardvark

Completely disconnected the Dewhurst and connected the motor 'as was' direct to the 240V supply and it runs as before, so panic over on that front. #phew

Is it possible to ****** up a Dewhurst switch? Logically it shouldn't be, but what do I know..... Don't understand where the flash/bang and magic smoke could come from...or why

I don't want to get involved with 3Ph with inverters so will keep going with what I have. Would I be best just forgetting the d/hurst, but since you currently [see what I did there ] have a similar setup on yours I can see no reason for mine not to work?

See what appens when you mess with lectric string, usually a beer or 2 helps !

Just a suggestion, as I dont know what a Dewhurst switch is can I recommend a reverser switch from a tyre changer, it does not matter what make or model of tyre changer, as basically we used to fit the same switch to 3ph or 1ph machines from the last 30 yrs, my brother is still servicing tyre equipment so I know they are still available.

here is a link I found .
http://www.garageequipment.co.uk/Ty...027-Replacement-Forward-Reverse-Switch-for-Ty

 

[slim_boy_fat]

See what appens when you mess with lectric string,

Aye, I know........

I think I got the wiring set up wrong but chickened out in case I knackered the motor. Once I take stock I'll think it through again.....

This is the Dewhurst switch arrangement, much as your link does I think.

http://www.instructables.com/id/Wir...e-phase-lathe-mot/step4/Dewhurst-drum-switch/

 

[eestibob]

Aye, I know........

I think I got the wiring set up wrong but chickened out in case I knackered the motor. Once I take stock I'll think it through again.....

This is the Dewhurst switch arrangement, much as your link does I think.

http://www.instructables.com/id/Wir...e-phase-lathe-mot/step4/Dewhurst-drum-switch/

that's exactly the same, just has a nice lever and cover.

 

[slim_boy_fat]

Right lads, I make no apology for plowing on with this Dewhurst switch business - I'm like a dog with a bone....

Applying logic to things, it's a switch, is a switch, is a switch so basically not too much to be wrong with it? It occurred to me that I might have had the earth feed on the wrong connectors, is this possible? The red circled one on the end of bank 1 - 4 is where I had the 240V feed, linked to the corresponding one on the other side, could this possible have been the cause of the tripping and blown fuses first time round? Also, I notice some pitting on the highlighted contacts compared to the others. Another possible cause?

So....any ideas?