M. Moore
Titanium
- Joined
- Jun 8, 2007
- Location
- Vancouver Island, B.C. Canada
My really great 452 is giving us some grief. The main contactor is cutting in and out and it is quite random. Can happen with the machine on but not welding or when welding, it is happening more frequently now. When it welds it welds fine, no problems.
The main contactor sometimes clicks several times and then pulls back in or stays off. I opened it (contactor) up and the contacts inside all look quite clean and in good shape, no nasty blackness or signs of corrosion, the machine is 13 years old. I checked the resistance across the main contactor and it was 0.2 on all three legs, it is running at 208 three phase. The machine is labeled as 240, 480 or 600 volt.
The local repair shop suggested that it might be a low voltage fault causing the coil to drop out, if this is the case how to test for the fault? I did check the voltage at the main ON switch and it was 22.3 volts. The main contactor coil is rated at 24 volts. How low would the voltage have to be for the coil to drop out? 18 volts or less?
What is interesting is that when the main contactor shut off the light inside the main ON switch stayed lit, it appears the system is getting 24 volts without the main contactor pulled in.
I would have thought that the 24 volt transformer would shut off with the main contactor?
If someone were kind enough to walk me through some simple tests that would be much appreciated.
Thanks
Michael
The main contactor sometimes clicks several times and then pulls back in or stays off. I opened it (contactor) up and the contacts inside all look quite clean and in good shape, no nasty blackness or signs of corrosion, the machine is 13 years old. I checked the resistance across the main contactor and it was 0.2 on all three legs, it is running at 208 three phase. The machine is labeled as 240, 480 or 600 volt.
The local repair shop suggested that it might be a low voltage fault causing the coil to drop out, if this is the case how to test for the fault? I did check the voltage at the main ON switch and it was 22.3 volts. The main contactor coil is rated at 24 volts. How low would the voltage have to be for the coil to drop out? 18 volts or less?
What is interesting is that when the main contactor shut off the light inside the main ON switch stayed lit, it appears the system is getting 24 volts without the main contactor pulled in.
I would have thought that the 24 volt transformer would shut off with the main contactor?
If someone were kind enough to walk me through some simple tests that would be much appreciated.
Thanks
Michael