plc_user1973
Member
Hello all,
what is the best solution to this problem. If a piece of equipment comes with a panel box containing all the motor starters(120V coils) that operates the machine attached to the machine. The wiring is 3 phase 480V. All that is needed is to provide the 3 phase power to it. My service is 3phase 480V Delta which drops to this panel box with a ground wire from the service to the panel box.
The control panel is several feet away from this machine and the wiring is through flexible conduit to the panel box on the machine. Several buttons on the control panel start and stop the starters in the panel on the machine. The control panel gets it power from a 120VAC 20 amp breaker from a breaker panel near the service entrance. It has its own ground wire from the breaker panel. Is there a problem with ground loops when this occurs? I mean we have several grounding points. One, on the machine and one on the control panel. Is this a problem? Should all the grounds run back to the machine where a ground wire returns from every motor on the machine. Every motor has its own ground plus the ground wire coming from the 3 phase service bonded in the panel on the machine. Or should all the grounds be terminated in the control panel where a PLC is located? To me it seems there is a potential for ground loops because of possible different ground potentials.
Any advice is appreciated.
what is the best solution to this problem. If a piece of equipment comes with a panel box containing all the motor starters(120V coils) that operates the machine attached to the machine. The wiring is 3 phase 480V. All that is needed is to provide the 3 phase power to it. My service is 3phase 480V Delta which drops to this panel box with a ground wire from the service to the panel box.
The control panel is several feet away from this machine and the wiring is through flexible conduit to the panel box on the machine. Several buttons on the control panel start and stop the starters in the panel on the machine. The control panel gets it power from a 120VAC 20 amp breaker from a breaker panel near the service entrance. It has its own ground wire from the breaker panel. Is there a problem with ground loops when this occurs? I mean we have several grounding points. One, on the machine and one on the control panel. Is this a problem? Should all the grounds run back to the machine where a ground wire returns from every motor on the machine. Every motor has its own ground plus the ground wire coming from the 3 phase service bonded in the panel on the machine. Or should all the grounds be terminated in the control panel where a PLC is located? To me it seems there is a potential for ground loops because of possible different ground potentials.
Any advice is appreciated.
