Help with new NVR switch, please.

[MikeG.]

Is this plug a normal uk three pin plug?

Yes.

If yes I very much doubt any of the wires we are looking at come from there.

White does, from the live pin.

 

[MikeG.]

he said it probably wasn't an NVR on the machine previously......

It was. If you switched off at the socket, there would be a loud click from the switch a second or three later. Before that loud click, if you switched back on at the socket, the machine would run. After that click, switching the socket back on produced nothing from the machine until the green button was pressed again.

 

[MikeG.]

...... the piggy back would be for an emergency stop (I suggested it may have a switch on the doors. .....

It does.

 

[lurker]

I reckon........
Somewhere else within the saw is a terminal block that the plug three core cable goes to.

 

[MikeG.]

.....You need a new meter........

Absolutely.

 

[lurker]

Is this plug a normal uk three pin plug?

Yes.

If yes I very much doubt any of the wires we are looking at come from there.

White does, from the live pin.

But not directly, is my guess.

 

[novocaine]

That suggests it is only switching the live. White isnt a normally lead wire so thats internal and id agree with lurker that there is a terminal block somewhere with the earthing, neutral and live contacts. Red and black are confusing colours but id say the red is the line to all the door switches and the black goes to the motor. You need to confirm this by looking around the door switches or finding the terminal block. Look where the power lead comes in.
Fun this. (hammer)

 

[sunnybob]

Any piggy backing on an NVR switch voids the reason for an NVR switch. :roll: :roll:
Open the mains lead in box. Find the live and neutral in.
Open the motor cover box, find the two that feed the motor.
the rest is easy peasy.

 

[sunnybob]

This is a 350N machine
https://www.axminster.co.uk/media/downl ... manual.pdf
Page 34 is the wiring diagram.

If you can wait till tomorrow, I have a 350N (admittedly 2016 vintage) I will remove my switch and check.

 

[novocaine]

Ni. The piggy backed lead is from the switches on the door to pull the nvr to 0 potential and make it activate. Its how a seperate emergency stop is linked in to the switch. Its what a1 terminal is for on this switch. I really thing its time to stop asking advice on here and get a sparky to look at it im afraid mike. Much as i dont like saying that. I havent got it in front of me (neither has anybody else except you Mike).

 

[lurker]

Well, he (and we) should be convinced the answer wasn't as easy as it might have been.
As Novo says it needs prodding by some one who knows what they are doing.
I suspect I could sus it within 10 minutes if I had it in front of me, but I'd take another twenty to check my thoughts with a multimeter before plugging in.

 

[MikeG.]

The plot thickens. I have managed to get into the bowels of the machine. Here is the supply to the motor:

Much more significantly, this thing, a "magnetic contactor" is the hub of all the wiring:

The brown and blue here are definitely power in:

And these three (black, red & white under my finger) are the wires that go up to the switch position:

I can't see the wires from the micro-switch on the cabinet door.

This way more complicated than I'd imagined......

 

[lurker]

Well it makes far more sense now.

You know you had a “strop” with Osvaldd???
I do hope you are planning to take your own advice and note that several of us have suggested you need someone who knows what they are doing.

Edit: picture one , I can see a unearthed earth lead.

 

[MikeG.]

That "strop" where no-one got stroppy, you mean?

I've already left a message for my favourite electriccy-one.

 

[novocaine]

so the switch wasn't an NVR. (sorry, uncalled for). what you had was a pair NO/NC switches in a block.

that little box of tricks is acting as the NVR, it's a magnetic relay, you put power across pin 8 and 9 (a1-a2) which activates the coil and pulls the contactor to live, feeding the motor, it's industrial wiring rather than hobby shop. you need a NO/NC panel mount. I'm struggling to find the right packaging for you though. do you have a picture of the old switch?

Having said you can't do it with you KJD12, I need to sit and think about it for a minute, you maybe able to use the internal relay to let you use it as an NO/NC. your making me have to think now. damn it.

 

[MikeG.]

The problem which looms now is that it may be the box of tricks which has failed, rather than the switch. As I said, turning it on works, but I have to turn off via the socket.

 

[novocaine]

You'll be glad to here that it's most likely the NC switch that's failed. which is nice.
as you can no dowt see from your second picture, you've got 2 separate switches mounted in a block. if you unscrew that nasty dust cover you may find you can remove them separately. lets start there for today.

wiring it is now considerably easier. sort of.

 

[sunnybob]

As its old with no warranty, and you dont actually know whats faulty, it would be quite simple to discard the magnetic relay, and all that old wiring, and that old on off switch and rewire with the new NVR switch in its place.

If youre up for that, I'm pretty sure the dentists friend can give you wiring diagram of extreme simplicity.

 

[novocaine]

nothing wrong with having the contactor, it means the switchs can be 1a rated.

 

[sunnybob]

But why leave a 20 year old relay and 20 year old wiring in there? Its not going to last another 20 years.
Hes got the switch, and the wiring isnt going to cost more than fourpence three farthings.
me, I would just rip it all out and fit new