View Full Version : Help with Kollmorgen Servo star

12-08-2016, 12:14 AM
Good evening
I'm after some help with some ac servo motors and drives that Im hoping to use for my cnc lathe conversion. Ive had the dives for a while and had them ear marked for another project but they seem to be perfect for the lathe.

They are Kollmorgen servo drive CD, model CE06250. My question is that the manual (attached) appears to say that they can accept either 1 or 3 phase input but the case says that it is a 3 phase model. can anyone confirm that I can use these in single phase?

They look to have been wired for 1 phase but not 100% sure if that was original or the last owner trying them.

Thanks in advance

Boyan Silyavski
12-08-2016, 02:35 AM
It clearly states that Cx06* model could work both 1 and 3 phase -230 VAC

Take care of cabling and fusing, as they could draw each quite much , just look at current specs. Meaning you need a separate line to a bigger switch.

12-08-2016, 06:35 AM
Looking at that diagram, it looks as if it would run happily on single-phase. The diagram shows each supply line fused but as the notes say, if you use live and neutral, you should not put a fuse in the neutral line. The common HY 2.2KW inverters are just the same, it's just that most people don't realise that they could take three-phase input. The spec sheet gives the current requirement for single and three-phase input for appropriate fusing.

My main concern is that the drawing suggests an isolating transformer on the input, and I wonder about mains isolation in the servo - whether the transformer is required for isolation or just shows where you might need a voltage-changing transformer.

12-08-2016, 03:18 PM
Thanks Guys
I thought that's what it meant but I have not seen dual phase controllers. I wasn't sure if it meant available in 1 or 3 phase.

I will look into the isolating transformer, hopefully it doesn't need it.

Are all 3 phase input VFDs capable of running off single phase? Im trying to find a closed loop vector VFD (IMO VXR) but most of the cheaper ones on ebay are 3phase input.

12-08-2016, 04:10 PM
It depends on the VFD. Some have input voltage monitoring, some need derated, some can be fooled by connected live to two inputs and neutral to the other.
Just in case you're not aware, one thing you need to be aware of is input voltage.

In the UK standard 3 phase is 380/415V between phases, with 240V single phase being any of those three phases connected to neutral. If you wanted to connect 380/415V VFD to single phase, you would need a step-up transformer.

If you know the model of the VFD, google for the manual, and see what it says.
Alternatively, have you had a look on https://inverterdrive.com/ to see if they list anything suitable?

12-08-2016, 05:23 PM
As m_c points out, you do have to consider the between-phase/phase-to-neutral voltages. That might be what is implied by the 3-phase transformer. I use the common Huanyang inverter for my router spindle and like everyone else, I just use 2 of the 3 input terminals for single-phase input. I also have a nominal 5HP/3KW inverter (by ABB) for my lathe which uses a 3HP 3-phase motor. I run that off single-phase input but the problem is that, in effect, it derates itself. The way these inverters generally work is by rectifying and smoothing the input voltage to DC and then chopping that to produce variable-frequency output pseudo-AC. At higher loads, you start to get more ripple on the DC which is worse if it is only getting topped up once per cycle (single phase) rather than three times per cycle (three-phase). My inverter trips out above a certain load as a result, although fortunately above spindle speeds that I normally use.

12-08-2016, 10:23 PM
I will try to get them powered up over the weekend and see if they still work. I found some info on them but there seems to be an issue using the step/direction control. Motors are 8N and 2048 ppr encoders so would be a shame if I can't interface to them.