Renovating a Hardinge HLV-H

[BillTodd]

Applied power to the thing for the first time.

First I rewired the control transformer to accept 240v input (instead of 440) then checked the contactors were operating OK.

Checked the power feed controls - they were working OK, except I'd reversed the connections to the variable transformer so high speed was low and vice-versa (easily fixed).

I then bodged* my 440v VFD on, temporarily using the control transformer as a step-up. Got the spindle spining in both high and low speed and up & down the speed range.

But, while doing all this, I noticed the slow-start resister on the VFD was smoking (It's an old 5HP Toshiba device and has a softstart to prevent fuses popping on switch on). I powered down to investigate why the relay, which bypasses the resister, was not working. I had to take the VFD apart to find out why (I have no manual for this thing). I stuck it back together only to get no responce at all. I then realised I'd forgotten to replace the current limit lead (which has to be removed to get at the relay).

It popped a 600v 20A fuse and killed one of the IGBT modules :(
( a MG50M2CK1, if you have any in your pockets)

BTW Mike:

I found a couple of subtle differences between my machine and the wiring diagram from your site:

The spindle interlock contactor is wired in a different place it disconnects the 3ph only to the motor and the 1ph control power to the up/down contactors

A couple of spare contacts on the fwd/reverse switch are used to break the main contactor coil circuit - so if the fwd/rev switch is changed while running it stops the machine.

I'll draw a diagram of it for your site if you wish.


*(I do this sort of thing for a living, so by bodged, I do not mean unsafe)