[ronderkis]

I need to convert my R2E3 Bridgeport to 230 volt 3 phase. I have the schematic that shows jumpers positions of the transformers for to 230 volts. After I change the jumpers is there any thing else I need to do? I saw they had a conversion kit which makes me think I am missing something.

[meatwad]

You may also need to move the motor contacts to LOW VOLTS. I'm no expert though. Perhaps George AKA machintek will chime in and help you.

[ronderkis]

Your talking servo motors not spindle motor?

You may also need to move the motor contacts to LOW VOLTS. I'm no expert though. Perhaps George AKA machintek will chime in and help you.

[meatwad]

No I mean spindle motor contacts. But also the heaters on the spindle were probably part of the conversion kit. Again I'm no expert.

The servo voltage should be handled when you change terminals on the transformer per your drawing.

You do mean 3 phase 240VAC and not single phase here right?

[ronderkis]

Wow, just changing over to 230 volts is hard :-)

I need new fuses
I nee to change jumpers and wires on multiple transformers.
I have to change the overload heaters
I have to change the wiring on the spindle head.

Does that cover everything?
One person told me if I use the vfd I bought I no longer need the overload heaters nor some of the other spindle components :-)

[oldmach]

changing from 460 to 230 change the jumpers on t2 and t3 i did one just use the chart in the bp manual double check the jumpers also t1 i changed the heaters from 2437 to 2435 clark heaters dont know if i had to i just bought some on ebay the fuses are fine if i remember they are less amps in 460 than in 230 if one goes then change all not hard just time good luck

[oldmach]

460 to 230 also the spindle motor there is a chart inside the elect cover lv is what you want

[meatwad]

Ronderkis. We need to understand if you are using 3 phase or single phase power here. Since you mentioned a VFD I guess you mean single phase? This obviously makes a huge difference. I have a R2E4 that I converted to SINGLE phase 230VAC and use a VFD for the spindle.

[ronderkis]

Ronderkis. We need to understand if you are using 3 phase or single phase power here. Since you mentioned a VFD I guess you mean single phase? This obviously makes a huge difference. I have a R2E4 that I converted to SINGLE phase 230VAC and use a VFD for the spindle.

I just bought the mill last Friday. I was hooked up at the place I bought it to 480 3 phase.
I started reading everything I could find
I put it in my home garage. I only have 220 single phase.
I want to get it running, then convert it with the ajax kit.
I bought the vfd, figuring I would want it eventually.
I understand a little about electricity and know a little about reading schematics.
I was delighted when I read on this forum that the only thing on my machine that ran on 3 phase was the spindle because the vfd would take care of that. I could run the rest on single phase :-)
(Wow, lot of Is, please forgive me)


But after studying the schematics, I discovered unlike most R2E3s this one uses three phase to power ps1 (power supply 1), which is used for the servos.
So now I have ordered a 7.5 hp rotary 3 phase converter that is guaranteed to be extremely well balanced.

Most the transformers have been jumpered correctly, today. The main 20 amp fuse replacements have been ordered.

I just have not figured out where the heaters are located yet. Or even what they look like. I was led to understand that if I hook up the vfd, I would not need the heaters. :-)


Was hoping the wiring diagram for the servo was under the cap. Thank you for reliving me of that anxiety. Now if I can only understand them. :-)

[meatwad]

I'm not sure what you say makes sense. Your mill should be no different than any other BOSS 8-9 when it comes to 3 phase power. You can convert it WITHOUT using a phase converter. You are correct in that only the spindle uses 3 phase.

[ronderkis]

>I'm not sure what you say makes sense

This is what the book that came with the machine states.

'Bridgeport R2E3 Series 1 Installation and Maintence Manual' page 4-1
70 VAC three phase - line voltage is fed to transformer T2. T2 is a 3 phase step down transformer. It steps the line voltage down to 70 VAC Three phase. This voltage is used by power supply PS1. PS1 provides 100 VDC to the NC414 axis drive controllers.

In the same titled book, that someone referred to with a link on this forum, same chapter, same page, same paragraph, it said T2 was a single phase transformer that fed single phase to PS1 for the axis drive controllers.

I was kind of surprised there was that difference. I can tell your vary surprised there is that difference.

[meatwad]

I converted my Boss 9 from 208VAC (3)phase to 230VAC (1)phase. I'm not certain what differences(if any) there are on your Boss 8 going from 460VAC (3)phase to 230VAC (1)phase. But I can't see why this shouldn't be possible too.

The two transformers are on separate phases. Disconnect the primary of ONE of them and jumper it to the same terminal on the other, so now they're both feeding off the same phase... this is just "moving a tap", although you'll have to make an extension wire to reach from one transformer to the other.

you'll have to build a small relay board that will accept the inputs to reversing contactors and translate them into stop/start and direction inputs for the VFD.(but this is only after you sort out T1,T2).

FWIW: I think you will be much happier without a noisy converter running in your shop.

I was very lucky to get some great advice from a fellow Boss 9 owner who had already converted his machine to run on (1)phase power. I think it would be wise for you to seek his help also. PM me and I will send his contact information once I verify he is ok with me forwarding his info to you. If not I am happy to try to help you also.

[ronderkis]

I just went over and verified t2 has 1L1 , 1L2, 1L3 going to it and 3 lines coming off, so it is 3 phase.

Can you look at your t2 and see if you only have 2 lines going in and 2 lines coming off?

Why should you and I be so surprised about a small design change?

BTW I sure hope I am wrong and you are right, it will save me about $600 and some unnecessary work. And some vary unwanted noise.

[meatwad]

OK. it is sounding like you are right. I will check mine. It will be tonight before I can look at this again. In the meantime I did already get the "ok" to pass-on that contact info. PM me if you want it.

[bevins]

Hey, dont stop here guys. I have an R2E4 boss 9 that I am looking to convert to 220 single phase. I purchased a vfd and went to look at the trannies and the big transformer I think is T2 is a no brainer. just change the jumpers.
The other one T1 has no labels so I don't know what to change it to. Also the three hot ac 3phase wires. How do I wire the inputs to the trannies?

thanks Bob

[ronderkis]

I got my R2E3 to breath and move today :-)
It uses a hitachi vfd. And I got it set up to run off 220 volts single phase.
Unfortunately I had to use a 3 hp rotary phase converter because of transformer t2 and it's power amp p1. (Both are 3 phase :-(
I replaced one hot wire on transformer T1 so it would not use the wild leg off the transformer.

Transformer T1 was a real pain. The jumper wire chat (pin out) is vary clearly embossed on the hard plastic casing. Vary pretty but it was wrong on mine. I don't know how it became wrong perhaps from factory all those years ago. It was hooked up to 440 3 phase so no one noticed. It took me forever to figure it out but it was quite obvious.

Bevins I can tell you what all I had to do, but I have no idea what I am doing. (Just lucky to have so many knowledgeable people here to help)

[bevins]

Hi ronderkis,

I guess there is a design change because my R2E4 has only two wire going to the primaries, so I would have to assume that it is single phase. I think I know what I have to do but I need some assurance from someone that knows what they are doing....:-)

I have a VFD I can get running with 220 single phase but I will need to rewire spindle motor from 460 to 220 3 phase. Also will have to change the trannies from 460 to 230.

I was in touch with someone that is fairly close that knows these things but I guess something happened to him as he is not responding to my PM's, or he elects not to....:-)

[bevins]

I got my R2E3 to breath and move today :-)
It uses a hitachi vfd. And I got it set up to run off 220 volts single phase.
Unfortunately I had to use a 3 hp rotary phase converter because of transformer t2 and it's power amp p1. (Both are 3 phase :-(
I replaced one hot wire on transformer T1 so it would not use the wild leg off the transformer.

Transformer T1 was a real pain. The jumper wire chat (pin out) is vary clearly embossed on the hard plastic casing. Vary pretty but it was wrong on mine. I don't know how it became wrong perhaps from factory all those years ago. It was hooked up to 440 3 phase so no one noticed. It took me forever to figure it out but it was quite obvious.

Bevins I can tell you what all I had to do, but I have no idea what I am doing. (Just lucky to have so many knowledgeable people here to help)

Can you send a pic and or let me know how it is suppose to be wired?

[ronderkis]

I don't know how the vfd is suppose to be wired to the Bridgeport I only know how I did it :-)
I traced the 3 wires + green ground wires coming out of the junction box on the spindle motor to where they entered the cabinet then down to the black magnetic relay(?) where they fastened at the bottom.. I unhooked the 3 wires plus the green ground there and moved all 4 wires to where I wanted my vfd. Then wired those 3 plus ground to the output of the vfd. Next I added 2 wires plus ground between the vfd input and the bottom of the big throw switch on the right top of the big door. The green is ground and always goes to ground. The two wires I hooked up to switch. I used the left two because I use the 3rd wire on the right as my wild leg from the roto phase. If you want to send me your email address I will send you lots of good pictures of the wiring I did. I don't know if I did it right but it all works including the axis and controller. But the controller no longer controls the spindle motor although that can be done to.