Motor contactor and reversing switch wiring

[GraemeVW]

I have a single phase motor i need to wire up.
On and off buttons with a contactor and a reversing switch.
I'd like the off position of the reversing switch to also trip the contactor.
I think I've come up with a way to do it but wanted to check.

Live into reversing switch, neutral to contactor.
Forward live goes to the buttons
Reverse live also goes to the buttons but also goes to a changeover relay on the contactors outputs.
The contactor outputs are doubled up, 2 go to the motor run windings, the other 2 go to the relay. All 4 relay outputs go to the starter winding/capacitor but the changeover will be switching polarity.

The reverse/off/forward switch will never be switching load and can't start the motor.
The relay will also never be switching load as the contactor will always be off when the relay can be triggered.
The only way to start the motor is with the start button.

Make sense? Should work right?

 

[GraemeVW]

Opened the motor terminal box and this may be different to what ideas expecting. Although I thinkni can still do the same thing, but just a different relay.

Am I right in thinking this is a capacitor run motor?

And therefore, according to this, swapping the blue wire to the terminal above should reverse it?

I don't know if it matters, but I would have expected live and neutral to be connected the other way round, although I am not sure what I would have based that expectation on.

 

[GraemeVW]

Hmm, reading more, it may still be capacitor start. Pretty sure They would look the same inside the terminal box.
Easiest way to tell?
Spin it by turning the shaft fast enough and see if it breaks connection?

You may be able to tell I'm on the limit of my motor knowledge here and trying to get my head round it as I go.

 

[Seadog]

It's probably a capacitor start motor, which is a very different animal. Is there a data plate. No connection diagram inside the terminal box lid?

 

[GraemeVW]

It's probably a capacitor start motor, which is a very different animal. Is there a data plate. No connection diagram inside the terminal box lid?

Data plate doesnt mention, not sure if there is anything in the lid. I'll check.

I have pdf of the workshop practise motor books. I need to read them again. I thought I understood, but turns out I'm not quite there yet!

The capacitor does have motor start written on it...

Don't know if capacitor run motors use the same capacitors though.


Edit...
Nothing in the lid.
Although I can't strip it completely as I don't want to break the plastic end fan, it looks like once the pulled is off I can remove one end. If its got a centrifugal switch, it will be behind that.

 

[Seadog]

Motor start and run capacitors are different animals.
On the bench, disconnect the capacitor, make sure that the pulley is mounted to the motor, power on, the motor should hum. Spin the pulley and see if the motor runs. If it spins up there should be an audible click at around half speed, which will be the centrifugal switch opening.

 

[GraemeVW]

Motor start and run capacitors are different animals.
On the bench, disconnect the capacitor, make sure that the pulley is mounted to the motor, power on, the motor should hum. Spin the pulley and see if the motor runs. If it spins up there should be an audible click at around half speed, which will be the centrifugal switch opening.

I'll try that.
I'm pretty sure this will be cap start though.
I found another reversing wiring diagram and I think I'm back on track.
Curious though, why do I need to have a pulley fitted?

 

[Seadog]

Because try to spin the motor is a lot easier than attempting to grip the shaft between thumb and forefinger. Unless you're built like The Incredible Hulk, that is

 

[Chippie]

Curious though, why do I need to have a pulley fitted?

you wrap a thin rope around the pulley and pull it to get the motor to start…

 

[GraemeVW]

Because try to spin the motor is a lot easier than attempting to grip the shaft between thumb and forefinger. Unless you're built like The Incredible Hulk, that is

Ok, that's fine. I can spin it from the fan. The pulley needed heat to come off, didn't fancy wedding it back on.

 

[GraemeVW]

you wrap a thin rope around the pulley and pull it to get the motor to start…

Like my old lawnmower!!

 

[brightspark]

you wrap a thin rope around the pulley and pull it to get the motor to start…

stand on the motor and give the pulley a good kick with your boot works

 

[GraemeVW]

I think I'm over complicating this. The more I try and find out about the reversing connections, the more confused I'm getting.
All the different things I read, or diagrams I see, people use different terminology.

I'll get there, but this is making my brain hurt.

I'll look at it again tomorrow.

 

[GraemeVW]

Ok, motor starts even with the cap disconnected.
When it spins down though, you can hear the switch. The switch activates at a very low rpm, like 100 or so.

So it's cap start.

What's doing my head in I think is everything i read suggests it should have 2 terminals.
I guess having 4 terminals just means I don't have to split the connections from 2 into 4, but fornsome reason it's confusing me.

 

[GraemeVW]

Right, I drew it out and is it this simple?
This is how i thought it should be.

The thing is, the more I read, the more I'm doubting myself.

Edit... I'd need another terminal if this is right, just to connect the capacitor, so this drawing may be wrong.

 

[GraemeVW]

And assuming that drawing is right, this is what I was thinking with the relay

I appreciate the drawings are terrible, but I'm also trying to cook sag curry at the same time.

Edit, I forgot to draw in that the reversing switch also triggers the relay to swap the motor wires over!

 

[GraemeVW]

Oh, that's a modification of this diagram

 

[Seadog]

Your motor drawing is correct. Since you appear to have identified both sets of windings the rest is relatively simple.

 

[GraemeVW]

Last piece of the puzzle I need is a relay.

I have found what I want, 240v coil, dpdt, on a base with screw terminals.

However, it's Chinese and costs £5.
I assume it will be junk.
I can't find the same thing but less rubbish though. I can find a few things that may work, for ALOT more money, but there must be something like this, but maybe European made, have a chance if lasting, and costing around £20?
I like the fact you can unplug the relay and replace it if needed.

I don't know enough about mains voltage relays to know what's available though.

Edit...
Found one

 

[daleyd]

Last piece of the puzzle I need is a relay.

I have found what I want, 240v coil, dpdt, on a base with screw terminals.

However, it's Chinese and costs £5.
I assume it will be junk.
I can't find the same thing but less rubbish though. I can find a few things that may work, for ALOT more money, but there must be something like this, but maybe European made, have a chance if lasting, and costing around £20?
I like the fact you can unplug the relay and replace it if needed.

I don't know enough about mains voltage relays to know what's available though.
View attachment 404816


Edit...
Found one

Do you want a decent one? I’ll Chuck you one in the post for the cost of postage…