Simple?? question about a relay

[Mike F]

I recently bought a Miller Dynasty welder and a Coolmate 3 cooler for it. As the option for automating the cooler was $600, I opted against that purchase. What I am looking to do is get a relay so that when I turn on the welder, the cooler automatically turns on. I do not want to open up the machine and make changes since it would likely void warranty. The welder is 220V on a dedicated 50A circuit, and the cooler is 110V. I was looking at something like in the attached picture, but externally connected. Can someone point me in the right direction?

 

[theoldwizard1]

You will likely have to make something yourself. Maybe a 4x4 metal box with cover or possibly mount it inside.

You are going to need a separate 110V feed unless the welder has a 4 wire plug (not typical) or has a 110v convenience outlet via an internal transformer. Check eBay for cheap relays.

 

[wyliesdiesels]

So u want the cooler to turn on when u turn on the welder? U would unfortunately need to open up the unit and take 2 wires off the power switch and connect it to the coil side of the relay. This is because the outlet is always hot and u need switched power.

Other option would be to put in a disconnect with a 4-wire feed, connect the machines appropriately, leave power switch on on both machines and use thr disconnect to turn on and off.

 

[Mike F]

I figured it would not be straightforward. The other thing I was thinking was a current sensing relay, but I suppose I will just go the cheaper way...Tape an index card to the welder and write "remember to turn on cooler" on it.

 

[malibu101]

I figured it would not be straightforward. The other thing I was thinking was a current sensing relay, but I suppose I will just go the cheaper way...Tape an index card to the welder and write "remember to turn on cooler" on it.

My first thought also was a current sensing relay.
But I like simple, cheap, and easy too.

Also write on it- "turn off gas"

 

[Labradorian]

I recently bought a Miller Dynasty welder and a Coolmate 3 cooler for it. As the option for automating the cooler was $600, I opted against that purchase. What I am looking to do is get a relay so that when I turn on the welder, the cooler automatically turns on. I do not want to open up the machine and make changes since it would likely void warranty. The welder is 220V on a dedicated 50A circuit, and the cooler is 110V. I was looking at something like in the attached picture, but externally connected. Can someone point me in the right direction?

I was thinking about those dust collection systems where the operator turns on the piece of equipment and the vacuum dust collector turns on too, but I can't find something that would run a welder............BUT

this may kill your warranty too....
get a 2 or 3 pole contactor rated high enough for the welder(with a 120VAC coil) and put it in a small JB. you would have to cut the power cord to the welder and feed the 220V though contacts of the contactor.
Wire 120V to a switch then to the coil of the contactor and connect the same switch to the cooler. When you turn on the switch, the cooler comes on and the contactor closes to enable power to the welder. That way the welder will not work unless the cooler in turned on.

You could even mount the switch and contactor close to the welder.......what ever works.

Just an idea.

CHeers

 

[Labradorian]

I figured it would not be straightforward. The other thing I was thinking was a current sensing relay, but I suppose I will just go the cheaper way...Tape an index card to the welder and write "remember to turn on cooler" on it.

..Or that

 

[Mike F]

I was thinking about the dust collection systems as well. The relay would turn on a 110V cooler, not the welder.

 

[wyliesdiesels]

I was thinking about those dust collection systems where the operator turns on the piece of equipment and the vacuum dust collector turns on too, but I can't find something that would run a welder............BUT

this may kill your warranty too....
get a 2 or 3 pole contactor rated high enough for the welder(with a 120VAC coil) and put it in a small JB. you would have to cut the power cord to the welder and feed the 220V though contacts of the contactor.
Wire 120V to a switch then to the coil of the contactor and connect the same switch to the cooler. When you turn on the switch, the cooler comes on and the contactor closes to enable power to the welder. That way the welder will not work unless the cooler in turned on.

You could even mount the switch and contactor close to the welder.......what ever works.

Just an idea.

CHeers

Taking this idea one step further, why not mount an appropriate 240v outlet below the contactor j box and avoid the possible warranty issues of cutting the end off the cord!

 

[dogdog]

dunno which dynasty line of product you have,

Maybe you can do something about it with those 14 pin connectors.
Especially the A, B, G/K.... you should be able to call miller and asked them about it.

 

[Mike F]

That's a good idea. It's a Dynasty 280DX and yes, it has a 14 pin connector. I have a pedal attached to it, so I will likely have to call SSC (it's their pedal) as well.

 

[dogdog]

I think pin A gets a constant 15VDC..... K/G is ground at least for the 200DX I have (have to go out and verify that). and B is the return for A.....Not sure how lightly you can drive a relay with A & K/G without affecting A&B. There is a guy in Miller forum that repair welders maybe he can help you out. The pin out should be in your manual as well.

if it works.
You can get a solid State Relay that can be driven by 5VDC to 32VDC for cheap. but you have to use heat sink.

 

[kaffine]

Get a 3 pole disconnect switch. 2 Poles feed the welder with 240V and the third pole feeds the hot to the cooler. Then just use the disconnect switch to turn the welder on/off and it will also turn the cooler on/off.

I'm not familiar with the NEC to know if there are any rules against having power from 2 different breakers on the same switch like that. Could be an issue when working on the switch someone shuts off 1 breaker not realizing there is a second breaker feeding power to the other terminal. If there is issues with NEC with that plan you could then wire up a 240V coil contactor to the output of the disconnect switch and run the cooler off the contactor. Off course if this is a mobile setup that may not work as well.

 

[Labradorian]

Taking this idea one step further, why not mount an appropriate 240v outlet below the contactor j box and avoid the possible warranty issues of cutting the end off the cord!

of course! if I only waited 1 more second before I posted I would of said this......

 

[Labradorian]

Get a 3 pole disconnect switch. 2 Poles feed the welder with 240V and the third pole feeds the hot to the cooler. Then just use the disconnect switch to turn the welder on/off and it will also turn the cooler on/off.

I'm not familiar with the NEC to know if there are any rules against having power from 2 different breakers on the same switch like that. Could be an issue when working on the switch someone shuts off 1 breaker not realizing there is a second breaker feeding power to the other terminal. If there is issues with NEC with that plan you could then wire up a 240V coil contactor to the output of the disconnect switch and run the cooler off the contactor. Off course if this is a mobile setup that may not work as well.

As a electrical designer myself, this is not a good idea but would work. Im not going to tell you what codes it applied too but using a single 3 pole disconnect to switch to different sources at 2 different voltages is just wrong.

 

[purplezr2]

How about a wall on/ff breaker that turns both the welder and the cooler on, not sure if they even makes these...

 

[kaffine]

As a electrical designer myself, this is not a good idea but would work. Im not going to tell you what codes it applied too but using a single 3 pole disconnect to switch to different sources at 2 different voltages is just wrong.

Really only 1 voltage compared to ground anyways.

Could use a double pole disconnect switch then a small sub panel with a breaker for the welder and one for the cooler. That would be a better and safer method. This way there is only 1 circuit for the shutoff switch. Not sure if there are any small shutoff switches that double as a subpanel or not. I'm thinking there is but I can't remember if they had a single lever shutoff on it or if they just considered the breakers *** the shutoff device.

 

[Mike F]

I suppose the "simple" question was not so simple after all! Index card reminder is much simpler- and cheaper too( unless of course I do not heed the index card's instructions and burn up my torch)