Renovating a Hardinge HLV-H

[BillTodd]

Hi Mike, Did you download the '61 wiring diagram OK (not too big in pdf form)?

You might consider changing the sampling frequency as an experiment. If the motor is emitting higher frequency noises, it's often a function of mechanical resonance of the windings under load.

Yeah, I fiddled with a number of things (I'm currently running it at 16kHz 'cos the motor's lightly loaded and it makes it silent).

The 'catch flying motor' function is odd; it should have no difficulty re-syncing to a slower motor. However, it says in the spec that it auto-senses the number of poles on the motor, it's unclear if this is only happens when RUN is selected. If it only senses after RUN then that might explain why it wont sync to the motor.

After playing around with it some more today, I'm sorely tempted to add a microcontroller to the VFD's serial bus, just so I could adjust the drive parameters 'on the fly'. I'm sure it would be possible then to dispense with the speed change relays and just tell the VFD to STOP (cut the power) prior to a speed change and pick up at the correct frequency after.

The size of the filter capacitor on the DC bus actually has more to do with derating than the size of the diodes

I thought someone would pick-up on that :)

I've just re-checked the Siemens' data, there no de-rating for single phase operation. although it does suggest the large power ones may need an external choke.

Interestingly, the box has terminals with access to the HV DC supply, but the manual doesn't show them. However, In an earlier model manual I downloaded, it did show them and DC brake resistor terminals. I wonder if smaller modern capacitors allow Siemens to 'over-rate' the filter for 3ph?

[aafradio]

Hi Mike, Did you download the '61 wiring diagram OK (not too big in pdf form)?

I sure did. Many thanks for the effort!

Lessee...I got three e-mails in the batch this morning that had attachments greater than 75MB, so, no, it wasn't too big...:p

After playing around with it some more today, I'm sorely tempted to add a microcontroller to the VFD's serial bus, just so I could adjust the drive parameters 'on the fly'. I'm sure it would be possible then to dispense with the speed change relays and just tell the VFD to STOP (cut the power) prior to a speed change and pick up at the correct frequency after.

Sounds like an interesting project. After 40 years of battling customers to define requirements for a few zillion projects, I'm moved to curiosity over why one would need the capability to switch from low to high or high to low quickly while it is running -at least on a manual lathe - but as long as you're having fun...

I've just re-checked the Siemens' data, there no de-rating for single phase operation. although it does suggest the large power ones may need an external choke.

The elimination of derating seems fairly common in one horsepower and less units. I suspect it has mostly to do with the low cost of capacitors and the re-use of the circuit boards in the 20HP and lower lineup.

Interestingly, the box has terminals with access to the HV DC supply, but the manual doesn't show them. However, In an earlier model manual I downloaded, it did show them and DC brake resistor terminals. I wonder if smaller modern capacitors allow Siemens to 'over-rate' the filter for 3ph?

Of all the VFDs I've examined, all but one had easily accessible DC bus connections. The capacitor choice was likely made using a trade-off study of the cost of buying large quantities of one size versus smaller quantities of various sizes. That usually brings out the head scratching in those of us who buy the older stuff.