# VFD on my Bridgeport Mill: Enclosure Build, Wiring, Remote Panel



## chip_slinger

I'm plunging back into working on my shop and mill after a busy summer with too many other distractions. The current project is working on converting my Bridgeport over to using a VFD. I read a bunch and searched a lot, but I didn't find many guides on designing and building the VFD enclosure, so I thought I would document how I am going about doing mine. I'll update this post as I go along with more build details and documentation. Let me know if you guys are interested in anything specific and I'll try to address it. Alright, here goes. 

In preparation for this project, I bought a big metal control cabinet off of eBay a couple of weeks ago. This one is 20" wide x 24" tall x 12" deep and had some DIN rail and plastic wireways. It has a bunch of holes I will have to fill, but the price was right. Here it is out of the shipping box with a 6" scale on top:







I started today by cleaning out the enclosure, removing the backpanel and giving everything a wipedown. Then I stripped off all of the parts from the backpanel (DIN rail, wireways, etc.) Paint may come later, but it's not a priority now. I decided I would mount the enclosure to the mill before I did the interior layout and wiring, just to give myself some motivation.

My mill has a ProtoTRAK retrofit and that control cabinet lives on the right side of the mill's base casting, so I decided to put the VFD enclosure on the left side. Plus, that puts it closer to the motor wiring. The base casting doesn't have a large enough flat area on the side to accommodate the enclosure, so I have to build it out with a frame.

I have a stockpile of 80/20 extrusions and fittings, so I figured that would be a great frame. I started with two horizontal sections about 16" long. I drilled four holes in the casting with my hand drill and tapped them. A couple of clearance holes in the 80/20 and those were mounted:







Now I needed to cut down some L brackets that would attach to the vertical sections. I haven't gotten to wiring in my horizontal bandsaw yet, so I grabbed my portaband and used the horizontal's vice. Now I have my L brackets ready to go:










Two 36" vertical sections are next:




Enclosure in place and mounted to the vertical sections:







I punched two holes in the side for the master on button and the emergency kill switch. Mounted them up:







OK, now I'm moving on to the interior layout and wiring. I sketched out my schematic over the last week and have been ordering parts. The easiest way for me to work is to do a layout of all the parts with my schematic next to me, and go back and forth between the two:




Here's how the backpanel is shaping up so far. There is the VFD, braking resistor, enclosure fans, fan relay, thermostat for the fans, fuse holders, terminal blocks, enclosure power contactor and ground bar. I'm missing the VFD's fuses. 




That's about as far as I got today. Next up will be mounting everything to the backpanel, mounting fans to the enclosure, mounting the backpanel into the enclosure and wiring.


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## Charley Davidson

I'm assuming the spaces in between the paragraphs were supposed to contain pictures, I see none so I'm supposing they didn't upload.

From what I read I believe you are putting the VFD on the mill not mounted remotely, if so you may want to ask some of the more experienced electrical guys if that is ok or not. I believe I was told you are not supposed to because of potential harmonic resonance. Just a heads up it may be fine.

Pictures appeared after I posted, must be an issue on my end


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## UncleRuss

Yes, I remember you now.  You are the guy that has his shop in a palace with wains-coat walls and a maid.  The par-qua floor gave it away!

From what I see, you are doing a bang up first class job so far.  My Bridgeport has a door in the column behind where you mounted the enclosure.  I made a floor and back plate for the hole to mount the VFD  and other pieces on and pretended that is what Bridgeport meant to happen.  I have built and rebuilt many an enclosure.  The two rows of openings on the left side, I would seal them all off at once with a single plate.  They make a double-sided rubber tape about 1/2" wide.  Use this to stick the plate in position and secure with screws or rivets.  Plugs them all at once and saves the cost of all those oil-tite hole closures.  Same for the larger openings on the right side.  Just a suggestion to save a little time and money.  A squirt of gray on the outside and a squirt of white on the inside and all is cheers.  A blind man on a fast horse at midnight will never notice.

I have found through time it is the little things like this that make a job look like a pro did it or a hack.  We all like to display our work and be proud of the accomplishments.

I use my VFD for 1ph to 3ph conversion, ramp up and down for speeds, reversing, and basic motor protection.  My Bridgeport has the Reeves vari-drive and I continue to use that with a photo electric tachometer for display.  After I added 3 axis DRO I am one spoiled happy camper.  I work faster and more accurately then ever once I learned to trust the numbers.  I don't know where some of the ideas come from about VFDs but I have always been told one rule is to keep the distance from the drive to the motor as short as possible.  #2 rule, never mix power wiring and control wiring in the same conduit.

Fun project.  Keep us posted.  You are doing well.  Want a job?       :thumbsup:

You may want to consider mounting that one fan out the top left side rather than the top.  Reasoning is back there there is less chance for swarf to get dropped or blown into the interior.  A piece of window screen over the fan opening really helps too, and possibly a louver and filter.  These are cheap for the home shop guy to include.  Just more work.


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## Buzsaw

I am right handed and operate mostly from the right side of my mill. I have mounted the start stop station on the right side of my mill remote from my drive, which is mounted on the wall on the left side of my mill. I did this for easy access to the start stop button  so I do not have to reach across the spindle (work area). If you operate mostly from the left side then it seems your present set up will be fine.


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## chip_slinger

Charley Davidson said:


> From what I read I believe you are putting the VFD on the mill not mounted remotely, if so you may want to ask some of the more experienced electrical guys if that is ok or not. I believe I was told you are not supposed to because of potential harmonic resonance. Just a heads up it may be fine.



Actually, you want the motor conductors to be as short as possible, meaning you want the VFD as close to the motor as practical. That way, you are keeping the "antenna" to a minimum. 



UncleRuss said:


> Yes, I remember you now.  You are the guy that has his shop in a palace with wains-coat walls and a maid.  The par-qua floor gave it away!



Yup, you got me. But where did the maid come from?!



UncleRuss said:


> From what I see, you are doing a bang up first class job so far.  My Bridgeport has a door in the column behind where you mounted the enclosure.  I made a floor and back plate for the hole to mount the VFD  and other pieces on and pretended that is what Bridgeport meant to happen.  I have built and rebuilt many an enclosure.  The two rows of openings on the left side, I would seal them all off at once with a single plate.  They make a double-sided rubber tape about 1/2" wide.  Use this to stick the plate in position and secure with screws or rivets.  Plugs them all at once and saves the cost of all those oil-tite hole closures.  Same for the larger openings on the right side.  Just a suggestion to save a little time and money.  A squirt of gray on the outside and a squirt of white on the inside and all is cheers.  A blind man on a fast horse at midnight will never notice.
> 
> I have found through time it is the little things like this that make a job look like a pro did it or a hack.  We all like to display our work and be proud of the accomplishments.
> 
> I use my VFD for 1ph to 3ph conversion, ramp up and down for speeds, reversing, and basic motor protection.  My Bridgeport has the Reeves vari-drive and I continue to use that with a photo electric tachometer for display.  After I added 3 axis DRO I am one spoiled happy camper.  I work faster and more accurately then ever once I learned to trust the numbers.  I don't know where some of the ideas come from about VFDs but I have always been told one rule is to keep the distance from the drive to the motor as short as possible.  #2 rule, never mix power wiring and control wiring in the same conduit.
> 
> Fun project.  Keep us posted.  You are doing well.  Want a job?       :thumbsup:
> 
> You may want to consider mounting that one fan out the top left side rather than the top.  Reasoning is back there there is less chance for swarf to get dropped or blown into the interior.  A piece of window screen over the fan opening really helps too, and possibly a louver and filter.  These are cheap for the home shop guy to include.  Just more work.



Thanks. I have been accused of being anal, but I really can only live with something if I know I've given it a real good shot at my best effort. I don't like half-a$$ed attempts. 

I was thinking about relocating that top fan to keep out wayward swarf, but I have a filter for it and I may make some kind of deflector shield. We'll see when I get some of the interior wiring all set and get back to mocking up the enclosure. 



Buzsaw said:


> I am right handed and operate mostly from the right side of my mill. I have mounted the start stop station on the right side of my mill remote from my drive, which is mounted on the wall on the left side of my mill. I did this for easy access to the start stop button  so I do not have to reach across the spindle (work area). If you operate mostly from the left side then it seems your present set up will be fine.



Those switches are for master on and master kill of the entire enclosure, so I don't anticipate using them that much. The spindle run and stop buttons will be on a remote panel mounted near the ProtoTRAK interface on the right side.


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## chip_slinger

I spent some time on the project this evening after work. I mounted up most of the components to the backpanel. Braking resistor got locked down. Terminal strip for the braking resistor leads got added since the leads were too short. VFD got mounted. VFD fuse block got mounted. Added in a 24V DC power supply that I had forgotten to include for the remote panel indicators. 

Here's what the project table looks like at the end of the night after a cleanup:




I also started the wiring and sorted out the DIN rail components. The thermostat has a broken solder joint so I'll fix that in the next couple of days. Some wiring pics:













Here's what I'm thinking for the remote panel layout. Run/stop control, fwd/rev control, speed control, at speed indicator, zero speed indicator, drive fault indicator:




Finally, a gratuitous shot of my tool cart with some of the tools I used tonight:


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## Nightshift

Your doing a nice job there. You're gonna really like the VFD when your done. Since your in the process of building your remote panel, I thought I'd show you the one I built for my Bridgeport. Like you, I mounted my VFD in a separate panel box, but I located my on the rear of the pedestal out of the way. My remote panel box houses all my controls for not only the VFD (power on/off, run/jog, fwd/rev, speed pot, start, e-stop) but also for the accessories on the mill (lamp on/off, vacuum on/off, dro & tach on/off). I always use Allen Bradley 800 series switches and you can see this is crammed into a 10 x 12 x 5 deep box. I have a 2nd e-stop for emergency use at knee level mounted in a small box on it's own. Just thought this might give you some ideas for yours. Cheers, Bill


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## TAWP Tool

What a great thread! I'm in the process of painting and reassembling my J Head Bridgeport. I plan to use a Teco VFD mounted in a box similar to yours.

If you're interested in having a tachometer as other have done, check out the MachTach at http://www.machtach.com if you'd like to roll your own with lots of options. I have several of them on machines in my shop.

Please do keep us posted on your progress!

Guy in Sacramento


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## UncleRuss

What neat, clean, installations you guys have pulled off.  Bravo, Bravo.  This is the way all builds should look.  Even puts some big companies to shame.   :man:  Congratulations to you both.


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## chip_slinger

Nightshift said:


> Your doing a nice job there. You're gonna really like the VFD when your done. Since your in the process of building your remote panel, I thought I'd show you the one I built for my Bridgeport. Like you, I mounted my VFD in a separate panel box, but I located my on the rear of the pedestal out of the way. My remote panel box houses all my controls for not only the VFD (power on/off, run/jog, fwd/rev, speed pot, start, e-stop) but also for the accessories on the mill (lamp on/off, vacuum on/off, dro & tach on/off). I always use Allen Bradley 800 series switches and you can see this is crammed into a 10 x 12 x 5 deep box. I have a 2nd e-stop for emergency use at knee level mounted in a small box on it's own. Just thought this might give you some ideas for yours. Cheers, Bill



Bill, that's real nice! I like the look of your layout. Is that the machtach that Guy mentions below?



TAWP Tool said:


> What a great thread! I'm in the process of painting and reassembling my J Head Bridgeport. I plan to use a Teco VFD mounted in a box similar to yours.
> 
> If you're interested in having a tachometer as other have done, check out the MachTach at http://www.machtach.com if you'd like to roll your own with lots of options. I have several of them on machines in my shop.
> 
> Please do keep us posted on your progress!
> 
> Guy in Sacramento



I'll check out machtach. I've seen it before but had forgotten about it. Thanks. 



UncleRuss said:


> What neat, clean, installations you guys have pulled off.  Bravo, Bravo.  This is the way all builds should look.  Even puts some big companies to shame.   :man:  Congratulations to you both.



Russ, thanks. You may want to hold your praise for a little while - I found a bit of a flaw with the enclosure mounting interfering with the X axis servo last night. I had to tear apart the mounting and rethink it a bit. I'll update later tonight.


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## CanFire

chip_slinger said:


> The spindle run and stop buttons will be on a remote panel mounted near the ProtoTRAK interface on the right side.



If you can work it, an estop  on the left side might be a good idea.  If you're right handed, chances are it will be your right hand that gets you into trouble and you will have to reach the stop with your left.


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## chip_slinger

CanFire said:


> If you can work it, an estop  on the left side might be a good idea.  If you're right handed, chances are it will be your right hand that gets you into trouble and you will have to reach the stop with your left.



I think I'm going to put another Estop on the front of the machine, slightly out of the way but so I could bump it with a knee if necessary.


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## chip_slinger

So I had to redo the mounting. I overlooked the fact that the servo motor on the x-axis for the ProtoTRAK retrofit sticks out past the rear edge of the table. So, having the enclosure mounted the way I did takes up some of the y-axis travel. So, I went in the other direction, literally. I rearranged the 80/20 frame to be cantilevered off of the existing vertical post.







I also had to shim out the frame so it would be plumb, as I just couldn't stand the enclosure being that far out of plumb in that direction. 

I put in the holes for the fans. 4 1/2" hole saw wasn't very fun, but it got the job done. 




Mounted the enclosure on the new frame and I actually like it in this position much better. I moved the master on button and the emergency switch to the front door. Fans and filters are installed. 




I've also been working on the panel wiring. I fixed the thermostat for the fans (it had a broken solder joint inside) and wrapped up some of the loose ends. I put it in the enclosure and am getting close. Wiring to the motor, feeder wiring from my panel board and working on the remote panel are next.


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## chip_slinger

Did some work on my VFD install today. We've been traveling back and forth to NY lately to help my mother in law prepare to moves out of her house, so I haven't had much time in the shop lately, and probably won't have much in the upcoming weeks. 

Anyway, I finished off the panel wiring by wiring up the master on push button, the master on indicator and the emergency stop on the front door. You can see I keep my schematic with me so I try and keep myself on track. 




I also wired up the motor. I used 3/4" FMC and 10/4 SOOW and cleaned up the wiring box in the motor housing. I kept slack if I never need to tilt the head or swing it far. I will tag it down later. 










Here's some pics of the inside of the enclosure. You can see the motor wiring coming down and clear of all of the other wiring.










I also got started on the remote panel. I mounted the enclosure on top of the ProtoTRAK control box and used 1/2" LFMC, again with slack. Three sets of 6 conductor shielded control wiring got pulled through. 







Here's what the remote panel looks like. I'm not that thrilled with the layout on the enclosure, looks too crowded. But, I need to move forward on this project so I can get to making chips, so I'm going to live with it for now. I can change it later. 




I made the run to my panel board with 10/4 SOOW but didn't wire in the outlet yet. Also not sure where to mount the VFD's remote. I may put it on the right side of the ProtoTRAK control box. I'm getting there - getting antsy to fire this thing up!


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## UncleRuss

Chip-slinger you are a man after my own heart.  Using all those Tele devices, they are my favorite and really great for both cost and utility.  The line is also very broad as far a cam operations and specialty contact blocks.  But heck you know all that and that is why you use them too I'll bet.

Yes, those pushbutton stations are something else.  I also do not understand why they jam the devices so close together.  Isn't that a corker what they charge for the speed pot operator?  They should be arrested for highway robbery!  I started using the LED type indicators and so far have had great fortune with them.  Short lamp life has always been a problem, especially with line voltage devices.  24vac is my favorite for the low voltage applications but usually 120 vac control level voltage proves best for ease of use, part foot print, and cost in most installations.

I have a 48" finger break and 52" stomp shear and started making my own little boxes from 18ga material.  Weld the corners with a ox/acct torch, blend with a die grinder and after a coat of paint most people do not know the difference.  Down side is it takes a little time but not bad after you make a few.  Up side is you can have anything you want, on your time schedule for far less cost.

Us ANAL type guys need to stick together.  Is this what they mean by a$$hole buddies?  I digress.

Get that _*SWARF*_ airborne!


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## chip_slinger

I worked on finishing my VFD install this weekend. I started Saturday off going striper fishing with some friends (no luck), but was able to wire in a new 30A breaker and twistlock receptacle in the afternoon. I wired up the plug to the end of he SOOW and that took care of that end. 




Next was the remote panel wiring, which was fairly straightforward. The important thing is to keep track of what wire you are using for each connection. I labelled the three cables and made sure I wrote down the color and cable number for each connection as I made it.










Now on to the signal cables at the VFD end. Here I was pretty conscious of the wire routing. I wanted to keep these signal cables as far away from the power wires as possible to minimize electrical interference. That's also why I'm using shielded cable. Once they were all landed I tied the shield drain wires together and crimped them into a ring lug so I could land it on one of the ground terminals. 










I still had some rectangular cutouts in the enclosure that I had to fill or seal somehow so I tackled those next. I had some ABS sheet in my plastic scrap bin, so I cut it to fit and attached it with 3M VHB, which is amazingly strong stuff. On the top piece, I put a hole in that lined up with one of the cutouts and made a cut from the edge to the hole. This way I could get the VFD remote cable out of the enclosure. 
















That pretty much completed the control cabinet wiring and build. I checked the entire wiring job against my schematic, torqued all the connections and sealed up the enclosure. Then it was time to plug it in, hit the master on switch and it worked! Contactor engaged, pilot light came on, fans started whirring (I had to adjust the thermostat) and the VFD started right up!

I spent a little time setting the initial programming, getting the digital inputs and outputs setup and tweaking the motor ramps, and it works! It's really nice when something like this ends up like you imagined. I put the mill right to work making a pocket in a plastic enclosure for the VFD remote. 




I mounted it to the right of the ProtoTRAK control and called it good!




So, I'm finally done with this project and can get to sling some chips around! I'm sure I'll be playing with the VFD programming as I use it. Right now I have the limits set to 30Hz to 60Hz and am playing with the braking settings. The VFD is really nice and smooth, not noisy at all. I'm liking it a lot. I shot a quick video showing the whole thing in operation. Sorry for the shaky handheld phone video!

[video=youtube_share;Rz2HN9vjK7E]http://youtu.be/Rz2HN9vjK7E[/video]


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## chip_slinger

I just got a PM from a new member asking me about some details on the wiring. It jogged my memory and I realized I never updated this thread when I built another one of these VFD enclosures for my Clausing lathe. On that build, I did some videos showing the construction and a walk-through of the circuit. Here they are:

Part 1
[video=youtube_share;nmy47aZMM4Q]http://youtu.be/nmy47aZMM4Q[/video]

Part 2
[video=youtube_share;o69QEVtZIeA]http://youtu.be/o69QEVtZIeA[/video]


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## v7guy

It's a real shame all these pictures are dead


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## dlane

The red x's


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## Superburban

If you quote them, you can look at them in the reply box.


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## chip_slinger

I had another member ask me for the parts list that I used for this build. Attached is a pdf version (can't upload excel sheet) of the list I had in my files. I'm not sure it is entirely complete, but it should give some guidance on most of the parts and where to source them.


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## Linghunt

Looks  good.  Just saw this thread.  Did you post the schematic? Be happy to take a look at it and comment.  Typically grounding, neutrals and common get overlooked.  As an experienced design, I still say these are complicated issues in a design and overlooked the most. 

On a large machine build, I would spend the entire 1st day just verify the grounds, neutrals and commons are wired correctly. Techs would think I was crazy till I found errors. If you got everything correct you could be able to measure ZERO current with a current clamp. 

Looks like a Hoffman enclosure to me. Nice BOM too.  Description of wire I would add voltage rating, but I'm being picky.

*Question?  *Is the fan blowing in the enclosure or out.  I see filter on top.


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## chip_slinger

There are two fans, one on the bottom of the enclosure blowing in and one on top blowing out. They both have filters.


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## Jim Nunn

A very well thought out and executed panel.

 I do have one suggestion about grounding.  Terminating the motor ground to the PE terminal at the drive insures that EMI and RFI noise generated by the drive will be controlled by the drive.  However you should run a ground wire from the drives PE terminal to the panel ground and the area under the standoffs on the panel ground should be ground or sanded to the bare a metal.   all of this is to insure that the DRO and tach will not be affected by the electrical noise generated by the drive.  Again I have seen professional built panels that are not as well built as yours.


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## Linghunt

Jim Nunn said:


> A very well thought out and executed panel.
> 
> ......... However you should run a ground wire from the drives PE terminal to the panel ground and the area under the standoffs on the panel ground should be ground or sanded to the bare a metal.    ............  Again I have seen professional built panels that are not as well built as yours.



I like the entire quote, but left just my favorite parts.   I had the bare metal call-out on all of my prints for panels. When you are running ground, you must be careful to not add internal ground loops on the panel.  It's not critical on this panel but always good to have good fundamentals.  I like to draw out a schematic with just grounds, so they are visible.  Having a drawing for just grounds on a more complicated project was important, especially when I had new electrical techs learning my design style.   When you have package devices in a design like those VFD's and docs are poor, you can't really see all of the ground paths.  Sometimes you will need to break out the meter and check the frame to other terminals. Don't assume the engineer designing those devices was the greatest.   Shielded cable and routing becomes critical when you got to deal with noise in the 400khz range.  Tough to handle hard to understand what choices to make at times. Mu metal is one tool you can use.  Not heard of it, do some searching...

Smart DC motor controller, haven't seen one yet that didn't have something wrong.  I like Automaton direct for the low cost and solid documentation. Lead times and service great as well.

Siemens controls have serviced me well thou, they are just real expensive.  Gear going to Europe, I try and buy everything Siemens.  PLC's,  contactors, motor starters, Breakers, relays , etc.  Spare parts and access drives the choice. 

Home builds, never used them so far.

I did watch your videos,  I was feeling sorry for you with that hole saw.   I made my techs cut large square holes for vents and fans.  The Greenlee punches for the small stuff and those stepped drill bits are the trick tool.

For those big holes, a template and plasma cutter does the trick.  Template guides you around the hole so you can move faster and not melt the paint too bad. An air powered zip cutter works great too. 

How did you reference that DC supply in the cabinet?  Hooking a meter from ground to DC common what will you get?  Pretty hard to do with those wall-warts. Those things falling out can be issues too.   [e.g.  you got a machine billing out at $1K / hr or more, and it goes down from a wall-wart falling out.  Bosses be ******.]


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## chip_slinger

Hi, the panel was bonded to the VFD using the ground bar and the panel was bonded to the enclosure. And a ground was brought to the ground bar. Not sure it was all clear in the writeup.


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