controlling 230v magnetic switch from other locations

[Jeff C Johnson]

I hope this is in the right forum.... here goes.

My makerspace is looking at a Grizzly 3hp dust collector that runs on single phase 220 volt controlled with a magnetic switch along with a remote control system.

The system we're replacing we had a home-brew 12 volt system that you could turn on the 120 volt dust collector from various locations via a solid state relay. Of course, this won't work on a 220 volt appliance.

The system comes with a remote control, but that's useless to us as it's a) single point of use, and b) can get easily lost. We prefer to have multiple locations to turn on, maybe even integrate it into our blast gates (opening gate activates 12 volt line to turn on.

I'm familiar with contactors and such, but not sure how to integrate it into the mag switch of a grizzly DC. Any suggestions?

[Jim Becker]

The common way to handle this is to use a contactor that has the load side rated for the 240v amperage required by the dust collection system and either 120v or low voltage on the control side that you can trigger by any number of different easy and inexpensive methods. That would likely replace the magnetic switch because of how magnetic switches operate. This is the method I use in my shop. Although I chose to use a centrally located toggle switch (120v control), I could have also supported using a typical cheap holiday light wireless control setup to toggle the contactor, too, since control voltage has very little load of any kind...it just "flips the switch" in the contactor to turn on the 240v side.

Diagram of how my setup is, um...setup...which in general will work for most of these situations with just adjustment of the control side to suit the situation:

[Jeff C Johnson]

Thanks Jim, excellent explanation. Not having the dust collector in front of me to evaluate, it makes the purchase decision tricky. The online chat isn't much help in that area. My biggest concern was intercepting between the mag switch and the drive power. Did you happen to bypass a mag switch in your setup? I'm assuming that if I remove the switch I'll void the warranty, but that's a risk I'm willing to take.

[Malcolm McLeod]

Jeff,
Jim's method/graphic assumes a 120VAC coil in the DC's mag starter. I don't know his DC, or the specs on the Grizzly you are contemplating, but if you can find out this detail, it helps make informed decisions. If there is a schematic available, the coil voltage should be evident.

Your existing 12V to 120V system might very well work ... IF ... the solid state relay you are using has dry contacts available (which is what it sounds like you are using to switch power to old DC). You can use either the already wired 120V to drive the new DC's coil (if compatible), or source the correct voltage from a control power transformer in the new DC. Just run a wire (pair) from the DC's start control circuit to your relay. The relay will just be a parallel (alternative) path to energize the new DC mag starter. This assumes the existing relay will handle the voltage and amperage of the DC's coil (I'd expect only ~0.5 amp).

Need more info tho'. Do you have schematic of your existing set-up? Of the Griz?

[Jeff C Johnson]

Yes, my contactor is of the 120v variety (which can drive 240 from 120). My old setup is simply a 12 volt input that drives a simple 30 amp SS relay, not much to show. Here's the ckt diagram of the new one we're looking at is on page 43 of https://cdn0.grizzly.com/manuals/g0441_m.pdf. I tried to post an image here but couldn't due to size constraints.

[Leo Graywacz]

If you just have a contactor that is operated by a 12v coil system and the whole system doesn't run off of 120v to make it all go then you can just replace the feeds from the contactor from the 120v line to a 208v-240v line. I've never really seen a contactor that does 120v not be able to handle 220v. It's all in the current rating. If the contactor is rated at an amperage that is within the draw of your new dust collector then you should be good. Some contactors have HP ratings because of startup currents, so that might come into play.

Basically if you can access the bare contactor terminals for line in and line out then connecting 220v to them shouldn't be an issue. If this is a built in system that is plugged into a 120v outlet and that current is what feeds the line in and out on the contactor then you can't use it.

[Jim Becker]

My Oneida system doesn't have a magnetic switch. I bought a contactor with appropriate specification and implemented as shown in the diagram above.

[Malcolm McLeod]

My Oneida system doesn't have a magnetic switch. I bought a contactor with appropriate specification and implemented as shown in the diagram above.

Not to be combative, but generally I hear "magnetic switch", "motor starter", "contactor", and/or "start relay" used inter-changeably.....? Whether electro-mechanical (big 'thunk'), or solid state (barely perceptible 'tick'), they are functionally similar :: a (relatively) low power control voltage/amperage signal connects a high power voltage/amperage supply to a load.

Grizzly manual doesn't call out the coil voltage, so I'm still at a loss there. I see a transformer, but that may be for remote - if so equipped?? It is also possible that the transformer is there to break the line voltage (240VAC) down to the control and coil voltage - 120VAC, or even 24VDC? I did not attempt to x-ref the motor starter part number to the starter manufacturer.

However, IF the 12V system in use now has dry contacts rated for 240VAC AND part number NHD C-12D has a 220-240VAC coil, take the black wire on 3L2 to one side of those dry contacts. Then run a return wire from the opposite side of the contacts to the A1 terminal. Now connect the A2 terminal to 98 on the O/L and then 97 to 5L3. Toss the control board in the bottom drawer and use the 12V toggle switches and/or limit switches on the blast gates to drive the above dry contacts 'closed'. I would expect those dry contacts to carry ~0.5A at 240VAC.

[Darcy Warner]

3 wire control, as many start stop stations as you want.

[Bruce Wrenn]

Think about a current sensor located in panel box. One lead of each machine would have to pass thru it. Anytime a machine is turned on, DC comes on. Add a "cube timer" (delay on break) to allow DC pipes to be swept clean before DC shuts down. Sensor controls contactor for DC. Current sensors can be gotten off ebay, along with cube timer. Not my idea originally. It appeared in FWW, Aug 2000. That's what I have in my shop.

[Bill Dufour]

Easy way is to buy a heavy duty realy/contactor/starter with a 120 volt coil. Supply it with 240 and take 240 downstream. Wire the control coil so it gets 120 volt power from the existing relay setup's output. that coil will draw less then one amp from the existing system.
I would be Leary of converting the existing system controls to 120 volt. The existing wire and switches may not be rated for 120 volts
Bill D.

[cecil rolfe]

I used an airconditioner relay rated for 240v with a 24volt coil and 24 volt transformer
. I ran thermostat wire with 3way and 4way switches in 8 locations. been 15 yrs with noproblems

[Jeff C Johnson]

Not to be combative, but generally I hear "magnetic switch", "motor starter", "contactor", and/or "start relay" used inter-changeably.....? Whether electro-mechanical (big 'thunk'), or solid state (barely perceptible 'tick'), they are functionally similar :: a (relatively) low power control voltage/amperage signal connects a high power voltage/amperage supply to a load.



However, IF the 12V system in use now has dry contacts rated for 240VAC AND part number NHD C-12D has a 220-240VAC coil, take the black wire on 3L2 to one side of those dry contacts. Then run a return wire from the opposite side of the contacts to the A1 terminal. Now connect the A2 terminal to 98 on the O/L and then 97 to 5L3. Toss the control board in the bottom drawer and use the 12V toggle switches and/or limit switches on the blast gates to drive the above dry contacts 'closed'. I would expect those dry contacts to carry ~0.5A at 240VAC.

Magnetic switch is what they call it on their site. I have a 12 volt system now, but I can jigger it to server whatever I need, I just don't have access to the machine to look at the actual wiring. I was hoping someone here might have done something similar on a grizzly with a mag switch.

Yes, it does have a remote equipped.

Thanks.

[Jeff C Johnson]

Think about a current sensor located in panel box. One lead of each machine would have to pass thru it. Anytime a machine is turned on, DC comes on. Add a "cube timer" (delay on break) to allow DC pipes to be swept clean before DC shuts down. Sensor controls contactor for DC. Current sensors can be gotten off ebay, along with cube timer. Not my idea originally. It appeared in FWW, Aug 2000. That's what I have in my shop.

Yes, this is a good solution for many, though the 220 machines (as I understand it) don't work as well as you need the sensor on only one leg. It would have to be tied to an a gate system as well to open/close to prevent flow losses, though it could be manual.

That system wouldn't get me to the several floor sweeps we're putting in though, still need some manual control. Your proposed idea would work, just not what we were looking at initially. Thanks.

[Jim Becker]

Not to be combative, but generally I hear "magnetic switch", "motor starter", "contactor", and/or "start relay" used inter-changeably.....? Whether electro-mechanical (big 'thunk'), or solid state (barely perceptible 'tick'), they are functionally similar :: a (relatively) low power control voltage/amperage signal connects a high power voltage/amperage supply to a load. er and use the 12V toggle switches and/or limit switches on the blast gates to drive the above dry contacts 'closed'. I would expect those dry contacts to carry ~0.5A at 240VAC.

I don't disagree. But the "magnetic switches" that are often on woodworking equipment are setup so that losing power in front of them means the machine will not restart when power is restored. The makes sense for machines with whirling sharp things for sure! So unless the mag-switch has provisions for remote starting, if one wants to fabricate a contactor type solution for a DC hidden in a closet, the appropriately rated contactor would have to replace the OEM magnetic switch. I don't know if the Grizzly provided magnetic switch supports any kind of remote switching...