Remote switching for air compressor and dust collector

[Thomas Hutson]

http://www.ebay.com/itm/Square-D-251...3D281130732087 would a switch like this work?

Thanks,
Thomas

[Jim Dwight]

Before there were plastic boxes (back in the stone ages), all wiring was in metal boxes. The metal box has a grounding screw, in the back. That gets connected to the power feed in. The switch is then grounded by screwing it to the metal box. Works fine. But with a plastic box, the box doesn't conduct so you have to connect the ground wire to the switch. Metal boxes are still available and still work fine. I used them to wire my shop a couple houses ago because the wiring was in conduit and I found the metal boxes easier to connect to the conduit. They were also more resistant to damage.

[Thomas Hutson]

Before there were plastic boxes (back in the stone ages), all wiring was in metal boxes. The metal box has a grounding screw, in the back. That gets connected to the power feed in. The switch is then grounded by screwing it to the metal box. Works fine. But with a plastic box, the box doesn't conduct so you have to connect the ground wire to the switch. Metal boxes are still available and still work fine. I used them to wire my shop a couple houses ago because the wiring was in conduit and I found the metal boxes easier to connect to the conduit. They were also more resistant to damage.

Thanks Jim. That really cleared it up for me. Im showing my youth a bit in this thread I think lol. Just turned 30. Anyways did you see the switch I had listed in my previous post. it has a pilot light and everything build in and is rated for 30 amp 240v

[Mike Cutler]

Hi guys,
Another shop question for you all.
I'm buttoning up my shop at this point in time and want to get it ready for my shed that I will be building onto the back this coming spring. This shed will house the air compressor and the dust collector. The dust collector is a shop fox w1666 2hp 1550cfm unit and the label claims 12 amps. The air compressor is a husky http://www.homedepot.com/p/Husky-60-...602H/205389936 The spec sheet says its 15 amps at 230 volts.

The shed is going to be built on to the back side of the existing shop building and I want a way to control the air compressor and the dust collector from the common wall between the two. I am still unsure if I will wire both tools into the building directly or do plugs but regardless I need to be able to turn them on and off from the other side of the wall. What is the proper way to do this that will meet code. I would like to be able to have two switches on the other side of the wall that I can simply flip like a light switch but I understand there are limitations with regard to horsepower and motor starting switches of the double pole single throw variety that are required to switch 220v power.

Thanks,
Thomas

Tom

You need an interposing relay, it's the electrical contactor that Jim Becker identified. A 120VAC relay, or even 28vdc will control the relay that switches the power to the 220vac loads. I think there used to be a device called a "Ranger" that did this. I don't know if it worked through walls, but the controls could be on the shop side of the wall.
The relay in the electrical contactor will also have an adjustable current sense for thermal overload protection, or a separate circuit altogether to sense it. Grizzly has a nice Magnetic switch, T20551, with thermal overload protection built into it. I don't know that it could be mounted in a wall box though. It's more made to be attached to the machine.
This could also be accomplished with a manual disconnect switch. Kinda ugly, but it would be code compliant.
Hardwiring your two machines will bring another section of the code into play that you may want to exclude. Put the requisite twist lock receptacles onto the switched power, and plug the machines into the receptacle(s). The code stops at the receptacle. One downside is that many machines with higher power motors, are required by the manufacturers to be hardwired or void the warranty.
Whatever you do though, think toward the future. Both of the machines you currently have are relatively small, and which you may want to upgrade to larger machines later once you find out how nice it is not to have to move them around, or move around them, in the shop.I wouldn't run anything less than#10awg.

[Thomas Hutson]

Tom

You need an interposing relay, it's the electrical contactor that Jim Becker identified. A 120VAC relay, or even 28vdc will control the relay that switches the power to the 220vac loads. I think there used to be a device called a "Ranger" that did this. I don't know if it worked through walls, but the controls could be on the shop side of the wall.
The relay in the electrical contactor will also have an adjustable current sense for thermal overload protection, or a separate circuit altogether to sense it. Grizzly has a nice Magnetic switch, T20551, with thermal overload protection built into it. I don't know that it could be mounted in a wall box though. It's more made to be attached to the machine.
This could also be accomplished with a manual disconnect switch. Kinda ugly, but it would be code compliant.
Hardwiring your two machines will bring another section of the code into play that you may want to exclude. Put the requisite twist lock receptacles onto the switched power, and plug the machines into the receptacle(s). The code stops at the receptacle. One downside is that many machines with higher power motors, are required by the manufacturers to be hardwired or void the warranty.
Whatever you do though, think toward the future. Both of the machines you currently have are relatively small, and which you may want to upgrade to larger machines later once you find out how nice it is not to have to move them around, or move around them, in the shop.I wouldn't run anything less than#10awg.

i run the orange romex for all the 240v circuits

[Jim Becker]

The "interposing relay" / contactor that Mike and I mentioned can be obtained from a local electrical supply house or various other suppliers. As I mentioned, on the machine side, it should be rated for at least the amperage requirement for your machine. On the control side, you need to make a choice between 120v line voltage or low voltage for control. I went with 120v because that was easiest for me. I personally wouldn't try to switch the 240v machine voltage directly from a wall switch and feel that the contactor method is cleaner, safer and more versatile, especially for the DC if you want to consider LV with multiple points for switches in the shop, a wireless remote system or even blast-gate control.

[Thomas Hutson]

The "interposing relay" / contactor that Mike and I mentioned can be obtained from a local electrical supply house or various other suppliers. As I mentioned, on the machine side, it should be rated for at least the amperage requirement for your machine. On the control side, you need to make a choice between 120v line voltage or low voltage for control. I went with 120v because that was easiest for me. I personally wouldn't try to switch the 240v machine voltage directly from a wall switch and feel that the contactor method is cleaner, safer and more versatile, especially for the DC if you want to consider LV with multiple points for switches in the shop, a wireless remote system or even blast-gate control.

how would running this method effect my ability to run blast gate control. I was thinking that I would probably just go manual for those but please enlighten me. Im learning all sorts of new stuff every day. They already did the insulation. I havent put the plywood walls up yet. was going to do the celing 5/8 sheetrock this week after i get the chimney installed. so between all these things im learning a TON

[Jim Becker]

Since a contactor has a "control" side, you have the opportunity to interface it with one or more switching methods. For blast gate control, for example, if you went with a low-voltage control contactor and appropriately wired micro-switches, opening a gate would trigger the microswitch to turn on the collection system. Ideally, you'd want an electronic way to delay shutdown of the collector for a few seconds after closing a gate (similar to how a Festool vac works) so that little or no dust/chips is left behind in the duct, but that's not required. The same theory applies to using multiple wireless remotes that control a simple 120v switch that in turn, controls the "control" side of your contactor. This separation of "control" from the "power" to the tool is what gives great flexibility as well as makes for a safer and cleaner install.

Me...I went with a single, simple 120v switch centrally located in my shop to trigger on/off for my cyclone in the closet. It's within a few steps of any tool/workstation and hasn't let me down yet, like previous attempts to use multiple wireless remotes, etc. Simple is hard to beat.

[mark mcfarlane]

...
Me...I went with a single, simple 120v switch centrally located in my shop to trigger on/off for my cyclone in the closet. It's within a few steps of any tool/workstation and hasn't let me down yet, like previous attempts to use multiple wireless remotes, etc. Simple is hard to beat.

Jim, have to seen such a switch on pull chain? Centrally located for me is going to be in the middle of a 30' * 34' room.

[Jim Becker]

Jim, have to seen such a switch on pull chain? Centrally located for me is going to be in the middle of a 30' * 34' room.

Theoretically possible...the control side of the contactor only cares if control power is "on" or "off". How you provide that on/off is a flexible situation. Before deciding on the contactor, you'll want to investigate actual switches like that so you can determine if you go line voltage or low voltage for the control side. That, in turn, will determine the specifications for your actual contactor's control side.

[John K Jordan]

Thomas,

My compressor and DC are in a closet and I control both from inside the main shop. Both are 5HP.

I didn't have time to read the entire thread but I use the exact switch that Andy Shearon linked to on Amazon. It is right outside the closet in the main shop, just a few feet from the compressor as the electron flies. I plug the compressor into a suitable receptacle and switch the receptacle. This has worked well.

I also brought all of my plumbing outside the closet so I can access valves pressure gauge, dryers, and regulator without going behind the wall. (The disconnect switch is on the far left)

air_comp_ctrls_IMG_20150124.jpg

If the distance was further than a few feet I would have used a contactor (relay) controlled by a 110v line.

I also put the dust collector controls in the main shop. Since unlike the compressor it needs to be turned on an off a lot it uses a contactor and a wireless control. This box contains the receiver and the bin-full monitor electronics. Two switches, one inside the closet and one in the shop with pilot lights enable/disable the controls. I wired in another of the motor disconnect switches inside the closet to kill the power to the contactor if needed.


DC_controller_box_ce.jpg DC_electrical_shop_s.jpg electrical_closet_small_c.jpg

I am not a fan of using the circuit breaker as disconnect.

JKJ

[Curt Harms]

I agree with "use contactors for heavy startup loads" camp as well. Larger air compressors and dust collectors both have substantial start surges. Contactors are designed to tolerate any arcing when the connection is made or broken. People have used inexpensive wireless lamp controllers to switch a contactor's control circuit (very low amperage) yielding an inexpensive but heavy duty wireless control setup. I'm in the hardwired-is-more-reliable camp but to each their own.

[Thomas Hutson]

Hey all. I took the 110v line that I had bundled up out of the wall and ran junction box to split it for a couple of switches that light up when flipped. I then took the output from those switches and tied them up neatly in the wall and replaced all the insulation etc. I'm not gonna get the shed built till next spring but when I do and I cut the hole to pull the wire through I want to make sure I have everything I need and it's all planned out.my trouble comes from the fact that I don't know what type of contactor and overload protection to use for the collector and an compressor. I need to buy a set for each and would like to get something that will take a large motor for both in case I upgrade either the collector or the air compressor in the future. Do they make a contactor wig built in overload protection? Prefferably something that would lend itself well to being mounted in a junction box on the wall?
Can someone send me a link to some products that will worK?
thanks
Thomas

[John K Jordan]

Hey all. I took the 110v line that I had bundled up out of the wall and ran junction box to split it for a couple of switches that light up when flipped. I then took the output from those switches and tied them up neatly in the wall and replaced all the insulation etc. I'm not gonna get the shed built till next spring but when I do and I cut the hole to pull the wire through I want to make sure I have everything I need and it's all planned out.my trouble comes from the fact that I don't know what type of contactor and overload protection to use for the collector and an compressor. I need to buy a set for each and would like to get something that will take a large motor for both in case I upgrade either the collector or the air compressor in the future. Do they make a contactor wig built in overload protection? Prefferably something that would lend itself well to being mounted in a junction box on the wall?
Can someone send me a link to some products that will worK?
thanks
Thomas

I don't have a specific link for a contactor, but I bought one for the DC directly from ClearVue. They have an electrical box option which has a contactor, box, wireless remote, outlets, etc. I also bought the McRabbet bin sensor from them as well but I rewired everything to put the controls in the main shop and turn the rats nest of wires into a neater, compact package. (I think I posted pictures before)

But any 120v-controlled 240v contactor rated for the motor load should work.

For overload protection, I ran a heavy cable from a 50 amp breaker to a sub-panel inside the closet with two smaller breakers, one for the DC and one for the compressor. I have the heavy duty 5hp motor disconnect switches close to the motors, one for the DC inside the closet and one for the compressor on the other side of the wall in the main shop, next to the plumbing, filters, and valves.

JKJ

[Malcolm McLeod]

Try this: http://www.ab.com/en/epub/catalogs/1...roduction.html (the "100-K" on the left of page).

Although for 3-phase motors, it will work for your DC and/or compressor. This series allows you to remote start via the starter coil (from your shop-side switches), it gives you adjustable overload protection for each motor, and has a manual shutoff for maintenance or lockout.

Edit: For a distributor, you could try here, tho' there ARE cheaper ways.