Hi to all. I have been called to take a look at a intdustrial type control panel that gets hot about 98 F at 80 ambient. The panle has a 200 amp main and only draws about 50 amps. Panel has about 30 contactors and a small type of a siemens plc aprox. 5 cards. after a short diagnose i saw that practycly all the cable connections wore loose and i went on with tighting all connections about 4 solid turns on every one.
Problem: after making sure that all connections wore tight i went on and powerd up the panel and the componets motors, valves etc. What i experianced was that 4 of the 30 contactors started chattering execevly. I waent on and replaced the contactors and the four stoped but another 2 or 3 started the chattering again i replaced the contactors and another two started the same problem. Can anyone explain? mesured the coil vboltage at 120 volts ac . what would cause this weird chattering. Thanks to all for your help.
Problem: after making sure that all connections wore tight i went on and powerd up the panel and the componets motors, valves etc. What i experianced was that 4 of the 30 contactors started chattering execevly. I waent on and replaced the contactors and the four stoped but another 2 or 3 started the chattering again i replaced the contactors and another two started the same problem. Can anyone explain? mesured the coil vboltage at 120 volts ac . what would cause this weird chattering. Thanks to all for your help.