An "easy when you know how" question.....

[slim_boy_fat]

As title, this is one of those. I know there are a few sparkies on here who'll know the answer for sure, so here goes....

I recently bought this to make my small RandA lathe safe(r) to operate:

As usual, it came with no wiring instructions , and opened up I'm presented with these three blocks of connections:

Question: how do I wire the power lead from the motor through this?

Thanks in advance, lads.

 

[daleyd]

What connections do you have at the moment? (ie do you have a forward/reverse/stop switch arrangement currently or is this new?)

The 2 green NO blocks are normally open, they don't have any connection until you push the switch, once energised the forward/reverse circuit should be latching to "hold" itself on.

The red block is Normally Closed and should be in the stop circuit, any push of the button breaks the stop circuit which will stop the lathe.

 

[Wendelspanswick]

The above switch needs to be used in conjunction with a contactor, its just 2 push to make buttons and 1 push to break.

 

[Luke]

As above, the intention is for the push buttons to control a contactor, or pair of changeover contactors, rather than to power the motor directly.

 

[Robotstar5]

Example of wiring diagram here

 

[slim_boy_fat]

At the moment, it's just a cable from the motor which I plug in the start the lathe - hence the need for something safer set-up-wise, as the socket is up behind the machine.

That's all I have [and about the limit of my knowledge on electrics] - what kind of capacitor would be needed? From memory the motor is 1/2 hp.

 

[Wendelspanswick]

A contactor, not a capacitor. A contactor is just a big relay, you could just buy a contactor for a few pounds but you would need to house it in a suitable box.
You might be better with a DOL starter which is a contactor in a box with switches.
http://www.toolstation.com/shop/p95364#item_detail
If you do go for a contactor you need one with a 240v coil, a 3 phase contactor will do as you just use 2 of the 3 or 4 poles.

 

[BrokenBiker]

I used relays on my r and a lathe, but that was only 1/6 hp motor. I used a 12V d.c. Control though, mainly because I had a 12v output tranny sat doing nothing

 

[Fazerruss]

If you want to reverse the motor then 2 contactors will be required. You will also need to find the start windings on the motor which are switched over by the contactors to change direction of rotation.

 

[slim_boy_fat]

I'm less worried about being able to reverse the motor to be honest - could I just use the blocks for start and stop without the need for a contactor?

It's beginning to look like a job for a local sparky, if I can find one.

 

[Fazerruss]

No you still need a contactor as they are only momentary switches

 

[Wendelspanswick]

I'm less worried about being able to reverse the motor to be honest - could I just use the blocks for start and stop without the need for a contactor?

It's beginning to look like a job for a local sparky, if I can find one.

No because you would have to hold the button in, the motor would only operate when the button is pressed, releasing the button disconnects the supply.

 

[AndyStobbs]

The wiring will twist your head the first time you wire one up.

 

[brightspark]

u would need a 3 or pole 240v contactor in conjunction with your switches just put a 20 amp double pole metal switch in the line and turn it on and off use the kis rule .......keep it simple

 

[slim_boy_fat]

.......keep it simple

I thought I had by buying that switch box - job for the sparky it is then.

Thanks for the advice/help lads, I appreciate the collective knowledge on here.