Hardinge TFB: do I have to feed it 575V or can I bypass the incoming transformer?

I have a gently-used Hardinge HLV-H TFB lathe (the non-threading toolroom lathe).

It came with a big grey switch box and a data plate that says "feed me a diet of 575V at 3.6 amps". See the pic of the data plate. I have 220V single phase in my shop.

I want to use all the nice Hardinge stuff (well-balanced motor, speed control, power feed, coolant pump). I do not just want to wire a VFD to the motor and jerry-rig the rest, even though I know it will cost a little (a lot) more.

The brute force method is to get a RPC to get to 240V 3-phase, and then a 3-phase transformer up to 575v.

HOWEVER, the first thing that happens when the 575V gets into the lathe is that it (all of it) goes into a transformer (see pics).

The wiring diagram is not much help (see pics).

Then it seems to go to another transformer and after that I am clueless.

Can anyone tell me what voltage it gets stepped down to after the first controller? It SEEMs like it goes to 230V, but that seems too good to be true (i.e. I could just bypass the transformer and hook a RPC directly to the leads at 240V 3-phase???).

This is a great little machine and I am DYING to get it working...


Bill

Basically, Hardinge designed the machine as a 230 machine, and then provided as an integral part of the machine a large three-phase transformer which was intended for adapting a U.S. machine to "international" standards, including Canada (where 575 is common).

So, that machine may be connected for 200, for Japan, for 380 or 415 for Europe, for 575 for Canada, or 230 or 460 for the United States.

230 is direct, bypassing the transformer. All others are through the transformer.

The best of all worlds, I would think.

I brief phone call to Hardinge should provide you with the recommended fuse ratings for the line voltage of you choice, plus a connection diagram.

TFBs (turn/face/bore) machines are rare, but are quite useful as these operations are perhaps those which are most often called upon.

Yet, the machine is built to the same very high standards as an HLV-H (after all, they DID call it a TFB-H).

Of course, the machine is three-phase, and this means utility three-phase, RPC three-phase, or Phase Perfect three-phase.

Nice machine!

--->Update - I went back to Steve and he agrees with PeterH, just bypass the transformer and hook up the RPC and voltage stabilizer direct to where the transformer connects.

Without those transformers, there's no need for the 5hp model, so the CNC PAC-3 is $900 + shipping for the RPC and electronics to manage the sine wave. I should get it next week, and then we'll see if I can get it connected without letting the magic smoke escape...



Thank you, PeterH. That's great advice.

I put a call in to Hardinge USA but was on hold for 45 minutes before I gave up and pressed 1 to leave a message. The diagram I have says to use a 15 amp fuse when running at 230V.

I've been corresponding with Steve at 3phaseconversions about a RPC and voltage stabilizer package. He recommends the 5hp rig at $1295 ($100 off list).

Compared to other RPCs, it seems higher than ebay specials, but I like the idea of putting quality power into this machine, and with a 5hp rig I could add a 230v 3-phase mill when I found one. Am I about to get fleeced? The smallest PhasePerfect ships at $3000, which for me is too much to pay for the silence of not running a RPC.

One thing - Steve seems to think I need to put 230v into the big transformer on the front end, not bypass it. That seems wrong. I will be sure to ask Hardinge USA if they call me back. Otherwise I'm inclined to connect the RPC/CNC Pac-5 output to where the transformer connects to the rest of the box, but with three fresh 15amp fuses in-between. Then let er rip.

The three-phase transformer is an isolation transformer, as I read the diagram.

Isolation transformers are OK with RPCs and Phase Perfect, but usually not OK with VFDs (although a VFD as a "phase converter" is not necessarily a good choice).

peterh5322 said:

The three-phase transformer is an isolation transformer, as I read the diagram.

Isolation transformers are OK with RPCs and Phase Perfect, but usually not OK with VFDs (although a VFD as a "phase converter" is not necessarily a good choice).

Click to expand...

The diagram calls it an autotransformer.

Bill

9100 said:

The diagram calls it an autotransformer.

Bill

Click to expand...

It surely does, doesn't it?

No matter, for its intended purpose, operating what is basically a 230 machine on any of 200, 230, 380, 415, 460 or 575 it will definitely do the job.

Hardinge tended to use consequent pole spindle motors, and these are necessarily single voltage motors, hence the transformer for the other voltages.