Dust Collector Project – Part 2

This is the second post in a series covering the installation of the dust collection system for my workshop.  The previous post can be found here:

Dust Collector Project – Part 1

In this part of the series, I intend to tackle setting the system up to operate with a wireless remote. But first a little background.  The dust collector is now mounted to a shelf on the wall.  This has decreased its footprint, but it has also made it somewhat difficult to get to the on/off switch.  Even were this not the case, I would still like to add a wireless remote, as it will make the system much easier to use.

My first choice to accomplish this was to buy a commercially available wireless remote switch. 120-volt remote switches are a dime a dozen and can be found easily.  These remote switches will easily handle low amperage loads especially on resistive circuits (i.e. light bulbs).  In fact, you will often see these sold as Christmas light remotes.  However, remote switches that will handle 240-volt current, at higher amperages, and on inductive loads (i.e. capacitor start motors) are harder to find and much more expensive.

I found that Grizzly had a newer model 240V Dust Collection Remote.  It was about $60 with tax and shipping, by far the cheapest commercial option, so I thought I would give it a try.  Don’t buy it… It’s crap!  I ordered one and when it arrived plugged in according to the directions.  I pressed the on button… nothing.  I pressed again, and again, and again. On about the tenth attempt the dust collector finally turned on.  I then tried to turn it off. You guessed it, nothing happened.  After about five attempts the collector finally turned off.  I  tried this several times, from various location in the shop, even with the remote 12-inches from the switch, and the situation never improved.  I contacted Grizzly and arranged to send the unit back.  Instead of asking for a replacement, I decided to build my own.

I decided to build my own remote system after reading a thread on Woodnet.net.  The original poster, Dominic Greco from Two Guys In A Garage Toolworks, also wrote a great article on his website showing the steps he took to install this system.  You can see his article here: Shop-Built Wireless Dust Collector Remote.   The system that I have designed is similar, but has a few changes that you’ll see as we progress.

Before I get started, I suppose I should give a little explanation of what this system is supposed to do.  The two main components are a 110v  wireless remote (Christmas light) switch and a contactor.  A contactor is an electrically controlled switch.  Essentially, one electrical circuit is used to switch on/off another separate circuit.  It is primarily used to allow a low power circuit to activate a much more powerful one.  A good example of this would be the thermostat in your house.  In this example, a 24-volt low-power wire runs from your thermostat to either your air conditioner or furnace.  When the thermostat senses that it needs to turn on the air-conditioning or heat, it sends a 24-volt signal to a contactor.  This contactor then closes the switch on a much higher power 240-volt high amperage circuit.  This turns on your heater or air-conditioner.  You may ask yourself, why all this hassle? Why not control the air-conditioner directly?  But, do you want 240-volt, 50A power running to your thermostat?  You touch this all the time, and if it shorts…

So, in my case, I’m going to use a cheap 110-volt wireless remote switch to send an electrical signal to an appropriate sized contactor.  This will turn on and off the much more powerful 240-volt circuit that goes to the dust collector.  This means that a 120-volt and a 240-volt wall outlet are both needed in the area where the system in installed.

Two other things to consider.  When buying a contactor, make sure you get one that takes a 120-volt signal.  If you buy a 24-volt controlled contactor, you’re going to fry it.  The other thing is checking to see what kind of switch you already have on your dust collector.   If it is a simple on/off switch that you can leave in the on position, you’re in business.  If it has a magnetic switch, you are going to have to do some googling to see how you can bypass it.

Last thing before we get started!  I’m not an electrician.  If this makes you nervous, don’t do it.  If you’re not sure if this meets code for your area, check.  Better yet hire someone. I’m not encouraging you to do this, only showing you what I did.  Electricity is no joke.  Proceed at your peril!

So, with all that out of the way, let’s get started.  I went to a few stores locally to get the best prices on all the relevant parts.  I did this over the course of a week while I was out running other errands.  I didn’t go driving all around town just to get these parts.  I went to my local electrical supply specialists (CED), Home Depot, a local plumbing supply place that also carried a lot of electrical stuff, and a local general store.  I purchased the 120-volt remote from Amazon.

Here are the parts that I purchased

1. Electrical Junction Box                                                $   9.00
2. Square D 8910DPA33V02U1 Contactor                    $ 35.00
3. 1/2″ Cord Grips (Nylon grommets)  –  2@ $1.92     $   3.84
4. 14/3 wire  –  5 feet @ $0.63/ft                                    $    3.15
5. 12/3 wire  –  5 feet @ $0.97/ft                                    $    4.85
6. 120V 15A Plug                                                               $    3.97
7. 250V 20A Plug                                                              $    5.19
8. Handy Box                                                                     $    0.68
9. Handy Box Face Plate                                                  $    0.68
10. 250V 20A Receptacle                                                   $     4.97
11. Offset Nipple                                                                  $    2.05
12. Conduit Lock Nuts                                                        $    0.78
13. Woods 32555 Remote Control Outlet                       $   14.20

Total Spent:                                                                           $  87.68  (plus the taxman)

The electrical parts that I purchased to build a remote control system for the dust collector.

Here’s the remote that I bought from Amazon:

120-volt Remote.

The contactor that I purchased from my local electrical supply specialist is heavy-duty. On a single phase, 240 volt circuit, it will handle 30 amps of inductive load.  This means it can handle motors of up to 5 horse power.  Way more than I currently need, but unlikely to wear out, and it has plenty of capacity if I ever upgrade the dust collector.

Square D Contactor Box.

Square D Contactor.

I put the contactor in the junction box and marked where holes were needed (you can just see the black dots below).  I then drilled these at the drill press.

Drilling some mounting holes at the drill press.

Here’s where the holes lined up.

I punched out three of the 1/2″ knockouts (2 on one side and one on the other).

I did not want to cut the plug off  the dust collector cord.  Admittedly, doing so would have made things a little simpler, as I could have run the cord directly inside the junction box.  Instead, I added a handy box that will house a 250-volt receptacle.  I connected the handy box to the junction box using an offset nipple and some locknuts.

Connecting the junction box and the handy box.

Here’s why the offset was needed.

Next I started to run some wiring.  14 AWG for the 120-volt line and 12 AWG for the 240-volt.  I used cord grips (nylon grommets) where the wire went through the wall of the junction box.

Starting the wiring.

The 120-volt line comes in the top cord grip and attaches to the contactor.  I just realized that the picture below doesn’t show it very well, but it attaches down low where you can’t see it, not to the top screws.  The 240-volt line comes in and attached to the bottom screws on the contactor. The top screws on the contactor are the line out to the receptacle.

All of the grounds were linked together and a ground run to the box itself.

All wired up!

Last, I added the plugs to the cables.

Plugs added and ready for installation.

When I mounted my dust collector to the wall, I used a plywood backer to support the brackets.  I attached the junction box to the plywood using washer-head screws.

Washer head screws used to install the junction box.

The 240-volt wall receptacle is above the shelf and the the 240-volt “line in” plugs in there. The cord from the dust collector plugs into the new 240-volt receptacle in the handy box.

Installed on the shelf backer board.

The wires need to be tidied up.

The 120-volt wireless remote switch needs to be placed in between the wall outlet and the 120-volt “line in” on the new junction box.   When the wireless remote activates the 120-volt circuit, this fires off the contactor and starts the dust collector.  I tested the system before plugging in the dust collector to the new outlet.  When you activate the remote, your hear a significant “SNAP” as the contactor activates.  I hesitated to use the word “bang” as it is not firecracker loud, but it is definitely more than a click.

I plugged the dust collector in and tested everything once more, and it works great.

I added the 120V remote switch.

I took the wireless remote and hung it on a hook on my band saw.  Since this is in the middle of my shop, it’s never far out of reach.

I hung the remote on my bandsaw which is in the center of my shop.

There are a few differences in my system from the one I linked to earlier.  Mine has a much heavier duty contactor.  Granted, I paid a lot more money for it than others available on amazon, but I think this one should give me many years of use.  I was able to off-set some of this extra cost by shopping around for the other parts and getting a pretty good deal on them.  The other difference is the addition of the handy box with the 240-volt receptacle.

I still need to tidy up the wires a little and I’ll probably use cable ties to do so.  All in all, I’m very happy with this project and I’m convinced it is way better than a commercial 240-volt remote.

A big thank you goes out to Dominic Greco for the inspiration to set my remote system up this way.

In the next post, I’ll be designing and making some brackets to hang my PVC pipe ducting from the shop ceiling.

More soon.

– Jonathan White