340V DC servos on eBay

[WoodSnarfer]

Every few days I come across Parker CompuMotors on eBay...really nice looking DC motors -- but, man, the label says "340 VDC".

There's no way to use these in a home-built CNC, is there? I wonder what their original application was, that required such high DC voltage (?)

-Chris

[Al_The_Man]

Were these DC brushless? There are amplifiers that are made to operate on 230vac 3 phase, this produces an internal DC supply of over 300vdc for the switching devices.
Al

[WoodSnarfer]

Ahhh...okay, yes they are brushless, so I understand the driver requirement now, thanks. 230VAC 3PH puts these out of spec for my 'home cnc' goals, though!

-Chris

[ESjaavik]

@WoodSnarfer: They are not necessarily 3ph input. They almost certainly is 3ph output to the motor. I have BLDC drives that are 1ph, or 3ph input, usually they are 240V/3ph when above 1.5KW, and 240V/1ph when below 1.5KW, YMMV. Reason is that the bigger drives would pop your circuit breakers if all the current is drawn from one phase only. Also the local grid would have an undesirable asymmetric load.

Are you looking at Ebay # 3860843520 ?
That motor seems to be small enough to be used with a 1ph drive. But buying the motor without a matching drive is only recommended if you know where to get a suitable drive, and how to (re)configure it. And since you had to ask, my guess is that you don't know.

[WoodSnarfer]

Einar,
I wasn't looking at that particular auction, but that one is very similar to what I've seen. There is a boatload of Parker Compumotors (I think the part number is CM233BE) on eBay. They all appear to be in 'like new' condition. All are 340VDC. I've seen them go for $50 USD with no bids. It's a shame...they look like really nice servos.

Right - I don't know where to get drives for these motors, and I don't think I want to move my design to 240VAC...although 240VAC at the router, with a sub-panel to break out 120VAC circuits for the computer, vacuum, etc...would be nice....hmmmm...

Drives for those motors probably cost a lot of money, I bet.

-Chris

[ESjaavik]

If I were to bet against you, I know I would loose, so I won't.

[Al_The_Man]

Originally Posted by WoodSnarfer I don't know where to get drives for these motors, Drives for those motors probably cost a lot of money, I bet. -Chris

Chris, If you ever want to second source an amplifier for a motor, it is worth looking at A-M-C they make a wide range of product for DC, DC brushless and AC sinusoidal etc. I have used there amps extensively and find them very easy to set up. They often come up on ebay for a good price. The larger ones are rare to find though, The small amps you might see on ebay listed as Galil are made by A-M-C.
Also Copley Controls is another make to look out for.
Al