Wiring a Bridgeport Mill - 1 phase to 3 phase

[vascon2196]

Okay......attached are some pictures of my current setup. I thought I followed the phase converter wiring diagram correctly. I purchased a receptacle that suited the male 4-prong twist-lock plug coming from the mill. With the 20amp double pole breaker flipped, I went into the shop and heard buzzing (humming) coming from the phase converter. I assume this is normal because it was not loud, just sounded like electricity was present.

I turned the mill on and the little red light on the phase converter came on and it began clicking...the mill motor did not run.

According to the troubleshooting guide the red light means the motor may be wired for 440v instead of 220v. Will this be obvious to check if I take the motor plate off and peek inside?

Please help...I hate electricity.

 

[stevehuckss396]

If it's a duel voltage motor the voltage on the name plate will look something like this "220/440"
If that is true then if it's a 9 or 12 lead motor and if the leads are numbered you need to connect

Line 1 to Wire 1 & Wire 7
Line 2 to Wire 2 & Wire 8
Line 3 to Wire 3 & Wire 9
Wire 4 to Wire 5 & Wire 6

CHECK THE NAMEPLATE ON THE MOTOR TO VERIFY

If for any reason this does not make sense, post a picture of your motor nameplate and if it's possible to use your motor, we'll get'er going.

 

[stevehuckss396]

BTW the connections in the box are a violation of the code. There needs to be 6 inches of "free" conductor in the box. You also need to staple the wire to the 2X4 within a foot of the box. Also cant tell but does the bare wire attach to the boxes? If not you need to take a little piece of bare wire and wrap it around the green screw and splice it to the other bare wires in both boxs.

 

[kvom]

Since you bought the mill from a friend, he should know what the voltage is.

 

[dman]

BTW the connections in the box are a violation of the code. There needs to be 6 inches of "free" conductor in the box. You also need to staple the wire to the 2X4 within a foot of the box. Also cant tell but does the bare wire attach to the boxes? If not you need to take a little piece of bare wire and wrap it around the green screw and splice it to the other bare wires in both boxs.

+1

also i wouldn't recommend a static converter for a mill. i'm not happy with the results on the van norman "head shop" machine i half own. uneven phases cause tool marks unless you bog the motor a little. i would have recommended a vfd but you can easily blow them if you wire things wrong. so get a few things straitened out in your current setup before you spend money on a vfd.

 

[vascon2196]

Thank you all for the quick responses. I'm heading out to the shop now to take a look at the motor. Also good to know about the violations. I may have one of the electrical shop teachers stop by and give me his "blessing" before I close everything up.

The nameplate does say 220/440...that I remember. The twist-lock plug also says 480V on it...

I will be back with some more information soon...thanks again.

 

[jwcnc1911]

I can't make it to the shop right now to show mine, but I use a great one by TemCO. Very reasonable and super quiet.

Here's a video I did shortly after we moved into the new shop:
[ame]http://YouTu.be/AvkCrB7THWc[/ame]

The phase convertor is still super quiet.

 

[jgedde]

BTW the connections in the box are a violation of the code. There needs to be 6 inches of "free" conductor in the box. You also need to staple the wire to the 2X4 within a foot of the box. Also cant tell but does the bare wire attach to the boxes? If not you need to take a little piece of bare wire and wrap it around the green screw and splice it to the other bare wires in both boxs.

Steve is right... I remember there being a caveat about the 6" staple requirement if the box has clamps where the wires enter the box (which yours does)

Nontheless, even if my memory of the caveat is right, the 6" staple rule is so well known and considered such good practice that most inspectors would likely zing you for it anyway...

So, you really should:

1) Staple the wires down to the studs six inches or less from the box.
2) Have much longer leads inside the box.
3) Ground the box.

Cheers!
John

 

[kvom]

I have one of the inexpensive voltage indicators where a 220V source lights it up.

http://www.ebay.com/itm/NOS-SPERRY-...604?pt=LH_DefaultDomain_0&hash=item58a1874024

You could use one of those or similar to verify that there is potential between each pair of leads to the mill. You can trace power from the converter to the junction box to the plug to the motor.

 

[Wizard69]

Okay......attached are some pictures of my current setup. I thought I followed the phase converter wiring diagram correctly. I purchased a receptacle that suited the male 4-prong twist-lock plug coming from the mill. With the 20amp double pole breaker flipped, I went into the shop and heard buzzing (humming) coming from the phase converter. I assume this is normal because it was not loud, just sounded like electricity was present.

This set off alarms in my head right away. You make an assumption here that the phase converter is working normally, it might be or it might not be. What is bothersome is that listening for buzzing is not a form of diagnostics.

I turned the mill on and the little red light on the phase converter came on and it began clicking...the mill motor did not run. According to the troubleshooting guide the red light means the motor may be wired for 440v instead of 220v.

Possibly. You may have other issues though.

Will this be obvious to check if I take the motor plate off and peek inside?

Maybe maybe not. The motor should have a nameplate and connection information stuck to it someplace.

Please help...I hate electricity.

Honestly this is a good indication that a professional would be of help here. That is an electrician with solid industrial or three phase experience. Yeah it costs a bit but I'd feel better about it as I don't want to see anyone harmed at your house. It is very easy to wire up something that works yet is unsafe. Frankly I have no confidence in being able to instruct one properly over the Internet in a forum like this, thus the suggestion to hire an electrician.

A couple of things to note:

1. If you want to get serious about doing electrical work for machine control you need the tools to do so. That starts with a good DVM, or Digital Volt Meter. Sometimes these are called DMM, or Digital Multi Meters as modern ones have many functions built in. It is no different than owning a car, there is little sense in working on a car, DIY, if you aren't willing to invest in the proper tools.

2. I highly recommend variable frequency drives (VFD) for installation of small machines in a home shop. It is a better more modern way to power three phase motors these days and often are a cheaper solution. Plus you get several real world benefits from a VFD, this includes, phase conversion, variable speed and soft start.

3. Every NEMA documented plug and socket has a proper operating voltage and current. You really want to be sure that the connectors you are using are being used properly. More so you want to minimize the use of connectors, cord ends or what ever you want to call them. Being able to plug a machine into the wall is fine, but I've seen some really horrendous over usage of cord ends for everything from a wiring extension to a splice. On a machine tool this is especially problematic due to chips and coolant everywhere.

4. Pay special attention to grounding! Remember these machines are made of conductive metal.

 

[Gordon]

[QUOTE=
2. I highly recommend variable frequency drives (VFD) for installation of small machines in a home shop. It is a better more modern way to power three phase motors these days and often are a cheaper solution. Plus you get several real world benefits from a VFD, this includes, phase conversion, variable speed and soft start.

I agree but even a variable frequency drive will require the motor to be wired to the correct voltage so his initial problem would still remain.

 

[vascon2196]

If it's a duel voltage motor the voltage on the name plate will look something like this "220/440"
If that is true then if it's a 9 or 12 lead motor and if the leads are numbered you need to connect

Line 1 to Wire 1 & Wire 7
Line 2 to Wire 2 & Wire 8
Line 3 to Wire 3 & Wire 9
Wire 4 to Wire 5 & Wire 6

CHECK THE NAMEPLATE ON THE MOTOR TO VERIFY

If for any reason this does not make sense, post a picture of your motor nameplate and if it's possible to use your motor, we'll get'er going.

Thank you Steve...this matched the diagram on the motor name plate. The motor was wired for the higher voltage (it said 400V on the name plate). I switched the wires to the low voltage configuration and everything worked great.

I did forget to add a switch to the electricity coming into the shed, which I will do next weekend. For now I just shut the breaker off.

Thank you again to everyone...your input is extremely valuable!!!!!

 

[stevehuckss396]

Good to here! Just need to get a switch ahead of the phase converter. Using the breaker that is not rated for "switching duty", you guessed it, another violation.

Now that you are armed with all this information I would encourage you to tear out all the wiring and do it again in a fashion that meets all the requirements but also looks neat and clean. Wont take very long and will be easier on the eyes.

 

[vascon2196]

Absolutely....thank you again Steve.

Thanks again to everyone who responded so quickly.

 

[vascon2196]

Okay.....my Bridgeport works fine.

I added a couple of 20amp receptacles so I can plug stuff in while in the shed and I added an 8ft long flouresent light.

If 220v are coming into the shed for my Bridgeport...how can I plug anything in? I plugged in a lamp and it immediately blew. The voltmeter says 220v? What good is a receptacle if I can't plug anything into it?

Also, the lights are not turning on? How do I run my machine off 220v but turn the lights on using 120v?

 

[dman]

Okay.....my Bridgeport works fine.

I added a couple of 20amp receptacles so I can plug stuff in while in the shed and I added an 8ft long flouresent light.

If 220v are coming into the shed for my Bridgeport...how can I plug anything in? I plugged in a lamp and it immediately blew. The voltmeter says 220v? What good is a receptacle if I can't plug anything into it?

Also, the lights are not turning on? How do I run my machine off 220v but turn the lights on using 120v?

ohh boy.

22v is 2 110v legs that are 180degrees out of phase. 110v is a single leg and a neutral. for a 110v circuit you need to install a sub panel and run a neutral to the shed from the main breaker box. you may already have one in the form of a ground but i don't know the code for sub panels. within the panel neutral and ground are connected to the same rail but when you go to a sub panel i don't know if you need 2 conductiors. basically the difference is that a ground shouldn't ever carry current unless there is a problem. it's a safety to keep the metal cases from being charged. neutrals carry current and are insulated.

once you have a proper sub panel you can install a separate single leg breaker for lights. and the neutral comes off the ground of the subpanel. like i said i don't know the code but logic tells me that the neutral back to the main panel should be insulated, but then again the ground coming into the main breaker from the street isn't. you may need to run a new cable to the main box.

you might be able to skip the sub panel but it means you should install a separate cable for the lights entirely all the way back to the main panel. you really wouldn't want to just add a neutral and run off the same breaker.

 

[ShopShoe]

Note: Local code and interpretation and practice differs. This relates to my USA location.

I have done two shops with sub-panels, but the last one was over ten years ago. Latest codes are stricter for grounding and other issues.

AT THE TIME I did my sub-panel, over two circuits in the shop required a sub-panel, regardless of voltage and number of circuits and current requirements of circuits. 50-Amp 230V service Minimum for the sub-panel. At least 6-guage conductors required to feed it, but use voltage-drop tables to determine size needed based on distance from main panel. Separate ground conductor required to tie ground at main panel and ground at sub-panel, plus bond cabinets to ground. Separate ground rods and ties to metallic water pipes required as well. Ground jumper around water meter or any non-metallic break in metal piping. New requirements add more grounding than this. All plugs must be GFI, but inspector was willing to discuss a situation regarding a single machine on a single circuit for which a suitable GFI was not available. Make sure all machine wiring is updated as required. I replaced old 115V machine plugs and cords with with molded-on-plug pigtail assemblies and made sure grounds were renewed: The inspector tested some of these as part of the inspection. I was required to remove covers as asked here and there.

I wired my subpanel with one 115V circuit only for installed, overhead lighting, Two circuits for 115V plugs, One 220V 20A circuit for air compressor, and one 220V 50A circuit for Arc Welder. Now that I have added my metalworking tools and covet larger ones, I find my panel too small and I am not sure I can pull larger conductors through the underground conduit that runs back to the main panel: Landscaping since the build has also put the underground even deeper, making a change very difficult. The price difference in using a larger size pipe with the smaller wires inside would have been very small relative to what it will cost to re-run this if I need.

A side issue of all of this is that my house panel needing to feed the shop is now out of expansion.

Hope this helps,

--ShopShoe

 

[vascon2196]

Thank you folks...having read your comments and concerns I have decided to leave this to the Electricians.

I always did struggle in those pesky electrical classes.

Thanks again for your quick responses!

 

[canadianhorsepower]

I plugged in a lamp and it immediately blew. The voltmeter says 220v?

it must have been pretty dam brightRof}
and for a very short time Rof}

Lightening fastRof}

 

[Sshire]

Chris
I think everyone here has breathed a sigh of relief at your decision to hire an electrician. Sometimes we think "hey, how hard can that be?"
I've done electrical work and paid attention to the code and it always takes way longer than we expected. Same with plumbing. With a professional tradesperson, we know that it's done safely.
That said, I wonder how many plumbers, electricians, carpenters, etc. have said "Hey, I could machine that. How hard can that be?"