Vac Motor Wiring in the "Black Box"?

[Mark Farris]

Hi all,
I am planning on finishing my version of Gary Campbell's Black Box vacuum system this week and have a question about wiring the motors. I am using 4 Lighthouse LH 7123-13 220V volt motors. All four will be switched separately and I will have 4 separate check valves so any combination of motors can be used. I know from reading the posts that the 4 motors can be ran off of a 30 amp circuit which typically requires a #10 wire. My intention was to run the power to a control box, through 4 DPDT switches rated for the proper amperage, then to the motors. My questions are; The motors come with very small gauge lead wires connected by push on terminals, what gauge wire should be ran from the switches to the motors (around 9 feet), and where should the neutral be attached as the motor has only the 2 line terminals? Also, if I am running only 1 motor @ 6.5 amps on a 30 amp breaker with a small gauge wire not rated for 30 amps where is the protection? Just doesn't seem right to me. I appreciate any help in understanding or suggestions.

Thanks,
Mark

[aschutsky]

Hey Mark, I'm currently starting to build out my black box as well. Just curious - what is the reasoning behind running switches to all 4 motors individually? Just to provide the option to kill the other motors when not needed?

With my setup, I plan on keeping it simple - all 4 motors wired to a big 30A rated switch or 30A 240V relay. I have 10/3 coming in and will wire that directly to the switch and connect all the motors together. There appears to be 2 hot leads coming into the motors with no neutral, but someone else can confirm as well. I'd be curious to see where others are connecting to the ground point though.

As far as your wiring - each motor is rated at ~7amps or so so I'd run a good 16 gauge to the switch if wiring individually. Technically you could get away with slightly less, but that is a small/cheap wire as is.

Andrew

[jTr]

I agree with Andrew on the wiring.
I've been running my "black box" for 2 years now, and offer these observations:

-Wired mine as 2 pairs of motors as advised. Primary pair runs alone 95% of the time. At my altitude, I realize about 5-7" of mercury. Some would be alarmed at these low levels, but things honestly work just fine.

-Remember, firing up additional motors will not likely bump your vac gauges up much at all, but it will increase the volume of air flow, which the gauge does not register.

-Secondary pair is used on occasion when I've got an undersized part, a sheet full of really small stuff, or a stubborn sheet of Russian Birch that's warped a bit. Just last week, I had one that stood 2" off the table. The set of 4 motors held them flat after I coaxed the arch down with a stick. Impressive.

-This is a critical point: Get an indoor/outdoor thermometer, attach remote probe to one of the primary motors and mount the readout near your other controls. Average running temp is ~ 114 degrees F. I've seen it hit 130 on occasions where a very low bleed material is being cut. I respond by opening an adjacent, unused vac zone to allow more air flow and cool those motors down. This contributes to longevity of the motors - the $10 investment is well worth it.

Once you guys get your systems running, you'll love it. You'll be rewarded in spades for all your efforts.

Jeff

[gundog]

I have been running 2 lighthouse motors on my vac setup for about 5 years now. I have mine setup to run 1 or both in parallel. I run only one motor much of the time. I do not cut through my material I cut to a skin because I cut plastic and small parts much of the time. The next time I set up a table I will probably use 4 motors switched individually like I do now with 2. I did not build a black box and mine is not automated as nice as the Gary Campbell design, but it works very well for me. I have a simple inexpensive automotive gauge for monitoring vac pressure I try to stay between 3" & 5".

I found if I seal it any better it will burn up a motor because of overheating. I lost one motor when I built my current setup by pulling 7" for a long period. I have since learned it only takes 3" to hold my parts and if I am pulling more than 5" I purposely create a leak to drop it down to allow more air flow.

I used a 3" vacuum manifold built using 3" ABS sewer pipe and RV type sewer dump valves. My main trunk line of 3" ABS is about 40' long and I run 1.5" pipe to each zone port most zones have 2 ports I have 2 small zones with one port each. Each port has an RV dump valve with the control rods ran to the end of the table. I ran my motors outside underneath a loafing shed that is next to my shop. When I had the motors at the table in my original design they were terribly noisy.

I will get some pictures of my setup and post them for you guys in a new thread later today.

As for the wiring if your motors are 220volt you don't need the neutral but you should run a safety ground. Run a hot leg to each of the motor connectors and the green ground wire to the safety ground tied into your electric panel. If you are running any 120 volt load on this service you will need the neutral for that load.

Mike

[gundog]

The neutral is a current carrying conductor in a 120 volt service on a 220 volt service the other leg carries the current in an AC circuit. So a straight 220 volt circuit the neutral is not used. If a service has both 120 volt load and 220 volt load the neutral is ran for the 120 volt load. I hope this makes sense.

Don't get ground and the neutral confused.

Mike

[ron_moorehead]

Ok if you have not change your mind here is a few things to think about, on your number 10 wire coming out of the breaker panel, both the white wire and black wire needs to connect to a 30 amp breaker, I would also use black tape and cover the white wire with black tape. Then the number 10 wire goes into your control box at that location I would mount 8 fuse holders and on the output of the fuse holder I would use number 14 wire going to your switches and then to the vacuum motor. In the fuse holder I would place 10 amp fuses. The four extra fuses are not really needed if you were to take one of the hot wire of the 220 volts and run it in number 10 all the way to the motors and take one wire from each motor and wire nut it to the common number 10 wire. You only need to fuse one side of the wiring going to the motors as long as you don’t step the wire size down. The thing about single phase power is both leg of the power going into the motor with have the same amount of current going through the wire. So with only one motor running both wires will have 6.5 amps full load, with two motors running both number 14 wires will have 6.5 amps but the number 10 wire will have 13 amps running in it and so on.

To make this real fancy I would add four light to your control panel on the switch side of the switches going to the motor a couple things looks nice but also lets you know if a fuse has blown.

I hope this helps.

[aschutsky]

I agree with Andrew on the wiring.
I've been running my "black box" for 2 years now, and offer these observations:

-Wired mine as 2 pairs of motors as advised. Primary pair runs alone 95% of the time. At my altitude, I realize about 5-7" of mercury. Some would be alarmed at these low levels, but things honestly work just fine.

-Remember, firing up additional motors will not likely bump your vac gauges up much at all, but it will increase the volume of air flow, which the gauge does not register.

-Secondary pair is used on occasion when I've got an undersized part, a sheet full of really small stuff, or a stubborn sheet of Russian Birch that's warped a bit. Just last week, I had one that stood 2" off the table. The set of 4 motors held them flat after I coaxed the arch down with a stick. Impressive.

-This is a critical point: Get an indoor/outdoor thermometer, attach remote probe to one of the primary motors and mount the readout near your other controls. Average running temp is ~ 114 degrees F. I've seen it hit 130 on occasions where a very low bleed material is being cut. I respond by opening an adjacent, unused vac zone to allow more air flow and cool those motors down. This contributes to longevity of the motors - the $10 investment is well worth it.

Once you guys get your systems running, you'll love it. You'll be rewarded in spades for all your efforts.

Jeff

Hey Jeff - thanks for chiming in. Do you have any pictures of your setup, would love to see. also are you using a check valve or flapper between the pairs of motors?

[jTr]

Hey Jeff - thanks for chiming in. Do you have any pictures of your setup, would love to see. also are you using a check valve or flapper between the pairs of motors?

Andrew,

For air management, I simply made a flap door.

This reminds me of a very important point you should be aware of:

Whether you use individually switched or dual pairs, they must be chambered and switched in sequence. If the secondaries are turned on and primaries are not, the vac is bled through the idle motors ahead of them. This means if you go with 4 individually activated motors you'll need to isolate each of those motors with check valves or flap doors from chamber to chamber. In operation, if you ran the fist and third motors, #3 would pull a bleed through chamber #2's idle motor.

Pics in the next post

[jTr]

And the pictures:

In the first pic, you can see switches on the wall with 10 gauge in and out on the left. Thermometer remote towards upper center, nested in the frame leg. Valtera valve pulls and vac gauges are mounted to/through framing on the right. Those plastic automotive gauge housings were dirt cheap and simple.

Second photo shows the vac box with 10 gauge leading to gang box housing for split to motors within. (Gary's dovetail jig sits on top - if you make drawers, you owe it to yourself to read up and try that someday as well - what a treat!)

Indeed, I do use dust collection, and own brooms and shop vacs. Fortunately, I have the 'bot at an angle to the wall, and I rarely see this side of the machine, never mind cleaning back there, but still... I am a bit embarrassed, and apologize for the bad example.

jeff

[aschutsky]

Jeff - Thanks for sharing. What are you guys using or doing for filtration going into the box?

[Mark Farris]

Wow, I missed a lot while I was at the day job.

Andrew, I do a lot of varied sized work. My plenum is 3/4" HDPE with 4-2x4 zones with the 4 in the "Y" direction. Each of those zones are fed with 2" pipe and a Valtera sliding valve from a 3" main. Each zone has 3 supply ports which will have individual "plugs" effectively giving me the option of 12 zones. The plenum grid is sized to accept Allstar gasketing. I have chosen to switch all four motors separately to give me complete control of how many and which motors to use.

Jeff, I like the thermometer idea...hadn't thought of that. My vac box has separate chambers and check valves for each motor. I am using standard 2" PVC check valves which I split in half and mount to the individual vac ports on the side of the box. These will be "tee'd" into a 3" main with will be connected to a filter(next project) and then connected via flexible connection to the Shopbot 3" main.

Michael, Good information. I meant ground but was in a hurry and had another voice in one ear and typed neutral.

Ron, You hit my question on the head. I had thought about separate fusing but wasn't sure. I have a fairly good understanding of general shop wiring and common sense was telling me there was a problem going from #10 wire to smaller, and that running a 7 amp motor on a 30 amp breaker just seemed wrong. I think your idea of 8-10 amp fuses between the #10 wire and the individual switches confirms what I was thinking. I also purchased lighted switches so I will know when a fuse blows.

I am planning an inline filter between the vac box and the Shopbot main line made out of a section of 10" PVC pipe, 3/4" sheet PVC, and a shop vac filter. I will post some pics of all this mess when I get a minute. Maybe I have over-thought all of this, but I like to try to be thorough (my wife calls it anal), and I remember Brady Watson telling others to make it your own way and learn what works for you. I appreciate all the information from all contributors to the Black Box sections of the forum and hope that maybe my ideas can contribute as well.

Mark

[ron brown]

Several years ago I built a vacuum table using two vacuum motors. Each had a 'check valve', a flap that shut and prevented 'backflow' and separate switches. I also had a micro-switch mounted to a flat panel that opened when the panel sucked in.

My 'zone control' was rubber balls I would set in ports of the areas I did not need. I could turn the vacuum motors on and pull down a piece of material. When there was enough vacuum to 'open' the micro-switch, one vacuum motor would switch off. It worked very well.

Ron

[Justin G]

Wow, I missed a lot while I was at the day job.

Andrew, I do a lot of varied sized work. My plenum is 3/4" HDPE with 4-2x4 zones with the 4 in the "Y" direction. Each of those zones are fed with 2" pipe and a Valtera sliding valve from a 3" main. Each zone has 3 supply ports which will have individual "plugs" effectively giving me the option of 12 zones. The plenum grid is sized to accept Allstar gasketing. I have chosen to switch all four motors separately to give me complete control of how many and which motors to use.

Jeff, I like the thermometer idea...hadn't thought of that. My vac box has separate chambers and check valves for each motor. I am using standard 2" PVC check valves which I split in half and mount to the individual vac ports on the side of the box. These will be "tee'd" into a 3" main with will be connected to a filter(next project) and then connected via flexible connection to the Shopbot 3" main.

Michael, Good information. I meant ground but was in a hurry and had another voice in one ear and typed neutral.

Ron, You hit my question on the head. I had thought about separate fusing but wasn't sure. I have a fairly good understanding of general shop wiring and common sense was telling me there was a problem going from #10 wire to smaller, and that running a 7 amp motor on a 30 amp breaker just seemed wrong. I think your idea of 8-10 amp fuses between the #10 wire and the individual switches confirms what I was thinking. I also purchased lighted switches so I will know when a fuse blows.

I am planning an inline filter between the vac box and the Shopbot main line made out of a section of 10" PVC pipe, 3/4" sheet PVC, and a shop vac filter. I will post some pics of all this mess when I get a minute. Maybe I have over-thought all of this, but I like to try to be thorough (my wife calls it anal), and I remember Brady Watson telling others to make it your own way and learn what works for you. I appreciate all the information from all contributors to the Black Box sections of the forum and hope that maybe my ideas can contribute as well.

Mark

So Ron, and Mark, you are taking all of the motor's and using one wire from each motor and essentially connecting that to the 10 gauge wire? Then the other side/wire goes to the switches? Did anyone answer where ground comes into play here?

I have a 220v 30A breaker coming from my shops panel, and it has a plug receptacle that I plug various machines into. Limited on breaker space so I have to plug/ unplug everything and can't have it permanently wired.

Could I run a setup like this:
Motors- 1 wire from each motor to #10 wire, other wire to: > lights > switches > fuses > #10 wire with plug > 220V receptacle > main shop panel. Running a ground from the motors all the way to the #10 wire with plug, which has already been connected from my main panels ground.

[Mark Farris]

Justin,
No the motor wires are not connected to the #10 wire. I used #14 wire (black, red, and #12 green ground) from the motors to the switch box.

At the switch box all #14 black and red wires are attached from each individual motor leads (1 black and 1 red each) to the outboard ends of a fuse holder. There is 10 amp ceramic fuse in each. The #10 wires from the inboard side of the fuse holder are connected to "lines". The green wire comes from " ground" to a ground post in the switch box then through and connected to 1 mounting bolt on each motor in series.

The plastic that Andrew and I both used for our plenums is King Starboard. Don't forget to have an inline filter and (1) - 1/4" minimum hole per motor for cooling air.

Please feel free to email me @ digifab12@gmail.com if you would like more info or pictures.

Mark

[Mark Farris]

One more thing. There is no learning value to copying mine or anyone else's system. There is a world of information on this site that covers many variations of the original designs by Gary and Brady and no one system is right for everyone. You will find us all willing to share our ideas and experiences but it is up to you to build a system that is uniquely yours and tailored to how you work. If I were to build mine again there would be changes, but it works great for me and i wouldn't want to be without it again. Experiment, fail, and learn. It is what makes us.......well us.

Mark

[larry_high]

GM Mark
did you have a chance to check the temp in your box? I am running about 162 F after 30 min and that's without a fan. the only time it goes passed that magic number is when there is too little air flow(10 or more "). when I am running at about 7-8" temp remains below 162.

Larry

[Justin G]

Thanks Mark, that makes sense. So you have the fuses before the switches? I got 30A toggle switches from HD instead of going with any kind of relays. I am basically going to wire nut a #10 wire and 4, #16 wires together for each line of the incoming power inside the box, then run those #16 wires to the switches/ fuses (whichever is better to be first). I am going to have 4 switches to control the motors independently, each motor with their own check valves held down by gravity and only opened when the motor is actuated. Before anyone chews me out, I am sure the system will probably need all four motors to cut full sheets with lots of parts. I am only doing this because its fun 1, and 2, I am kind of a freak about symmetry and do not like to run 2 motors most of the time, etc.

[Gary Campbell]

Guys...
Don't forget that when switching or fusing 220V lines, you must put a fuse on each line (8 singles or 4 doubles) and switches must be double pole as both hot lines must be disconnected. You must also ground all of the vac motor metal housings. There is a ground lug boss provided for this purpose.

There are volumes of online documents that give some basics to amateur electricians. This is slightly beyond the basics, read up before you kill yourself or a friend.

[knight_toolworks]

and when you get tired of these motors yo can go this way. I hated spending the money but i wanted the reliability and the quiet. http://i154.photobucket.com/albums/s266/knighttoolworks/posting/986E7808-ACBE-4CFC-BCAB-354697943A27_zpshyrmbdxi.jpg (http://s154.photobucket.com/user/knighttoolworks/media/posting/986E7808-ACBE-4CFC-BCAB-354697943A27_zpshyrmbdxi.jpg.html)

[Mark Farris]

Justin,
I am no electrical genius but I believe the purpose of the fuse is to separate and protect the lower amperage components from the higher. I am using a 30A 220V breaker feeding my setup into the switch box with #10 wire. The #10 wire runs to the inboard side of all 8 fuse holders (thanks to Gary for bringing that up), the #14 wire comes off the outboard side of the fuse holders to the double pole single throw lighted switches from McMaster-Carr, then to the motors. #14 wire is not rated to carry 30A and is protected, as are the motors, with a 10A fuse on each leg of the 220V power supply. The ground wire basically goes all the way from the ground source to the motor casings and is daisy chained between them.

Larry, haven't had time to check the temps yet, been too busy running it. LOL I need to make that a priority.

Mark

[Justin G]

Justin,
I am no electrical genius but I believe the purpose of the fuse is to separate and protect the lower amperage components from the higher. I am using a 30A 220V breaker feeding my setup into the switch box with #10 wire. The #10 wire runs to the inboard side of all 8 fuse holders (thanks to Gary for bringing that up), the #14 wire comes off the outboard side of the fuse holders to the double pole single throw lighted switches from McMaster-Carr, then to the motors. #14 wire is not rated to carry 30A and is protected, as are the motors, with a 10A fuse on each leg of the 220V power supply. The ground wire basically goes all the way from the ground source to the motor casings and is daisy chained between them.

Larry, haven't had time to check the temps yet, been too busy running it. LOL I need to make that a priority.

Mark

Mark,
thank you. I got my box all built out and it is running great. I will post a new thread so I do not hi jack this one. I elected to run the fuses after the switches, which i'm sure is not the best but my switches are rated for 30 amps each and there are four of them.