Contactor blew,what to ask for when buying a new one.

Suzuki4evr

Suzuki4evr

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Hallo guys.

T
My Mashstroy 3phase lathes contactor died and I want to replace it but I am not quite sure what to ask for. Can someone tell what exactly to ask for concerning amps,volts etc. to replace this old contactor,it was still original. I am running it through a vfd,but currently I can't use my lathe control panel,I must start the motor and stop on the vfd where I use to start and stop,run the flood coolant motor and estop on the control panel,but I can't do that now umless I guess I rewire everything and program the perimeters on the vfd to use the panel on the lathe. I don't know how the electrician,who sadly is now dead and was a friend of mine,wired it before,because before the contactor blew,I could use the control of the lathe. Any help is appreciated20210621_093211.jpg20210621_093201.jpg20210621_093146.jpg20210621_093048.jpg
 
Was the contactor between the vfd and motor, or before the vfd? Between the vfd and motor is not a good idea, can burn out the vfd quickly. Looks like it had a heater/current limiter, which isn’t usually needed if the vfd is set up right.

more information would be helpful. Are you running it on single phase or 3phase power? How many HP is the motor? What’s your line voltage?
 
How is it burned out? Has it been tested?
TEST DON'T GUESS
 
rabler said:
Was the contactor between the vfd and motor, or before the vfd? Between the vfd and motor is not a good idea, can burn out the vfd quickly. Looks like it had a heater/current limiter, which isn’t usually needed if the vfd is set up right.

more information would be helpful. Are you running it on single phase or 3phase power? How many HP is the motor? What’s your line voltage?
Click to expand...
Ok it was deffanatly between,and I know now that is not good,but I can't remember exactly how,but there was a transformer involved before I wired the vfd directly to the motor when the contactor went. Somehow the vfd survived for a long time and is still going strong(Yaskawa V1000).
rabler said:
. Are you running it on single phase or 3phase power? How many HP is the motor? What’s your line voltage?
Click to expand...
I am running from 220V single phase input configured to delta 380V three phase,if that makes any sense. Motor is 4KW three phase.

As I mentioned before,I guess I can rewire like I did with my mill recently and program the vfd,but uhg,lot of work. markba633 helped me with that.
 
sdelivery said:
How is it burned out? Has it been tested?
TEST DON'T GUESS
Click to expand...
You cant see it in the pics,but some part on the top are melted and black and it stopped working. I guess that was it for me. Will take a pic tomorrow.
 
Suzuki4evr said:
As I mentioned before,I guess I can rewire like I did with my mill recently and program the vfd,but uhg,lot of work. markba633 helped me with that.
Click to expand...
That's going to be your best option. VFD's combined with older contactor designs generally make for an electrical mess. Wire the VFD directly to the motor, use the VFD to control the motor - F/R etc. As long as your lathe has just the drive motor that works well. If it also has a coolant pump or other 3 phase electrical loads it gets more complicated.
 
The ebay listing looks to be labeled 16-21amps. The picture above looks to be a 32A (that may only be the DC rating) contactor with a 6 - 8A heater/overload protection, which would make sense for a 4Kw motor on 380V. I suspect there is more to the complete part number than AEG At00, as those current loads don't match up.
 
rabler said:
That's going to be your best option. VFD's combined with older contactor designs generally make for an electrical mess. Wire the VFD directly to the motor, use the VFD to control the motor - F/R etc. As long as your lathe has just the drive motor that works well. If it also has a coolant pump or other 3 phase electrical loads it gets more complicated.
Click to expand...
That is what I thought will be the outcome of this issue. Forward and reverse is controled by the lever on the lathe,so the vfd will be wired and programed for start,stop,coolant and traverse auto feed. Thanks for the input. I will be contacting my Varispeed agent for assistance and in the meantime read the manual. I have the vfd now for about 8years.
 
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