Cheetah
Member
- Location
- Rochester, NY
Situation:
Machines at various sites are fed with 208Y/120 three phase, with L1, L2, L3, and PE (protective earth) supplied to the machines. The neutral (N) conductor is not supplied to the machines. Inside each machine control panel is a jumper from PE to N. Some machines have L-N loads, some don't.
I advocate removing the N-PE connection on every machine and providing the N conductor to those machines with L-N loads. I have advocated this from a position of safety, stating that a "potentially lethal shock hazard will exist" should the PE connection to the machine be lost. Another engineer remains unconvinced that this is a legitimate safety issue.
I am looking for precise documentation and examples of how this is really a legitimate safety issue. Can you help?
Machines at various sites are fed with 208Y/120 three phase, with L1, L2, L3, and PE (protective earth) supplied to the machines. The neutral (N) conductor is not supplied to the machines. Inside each machine control panel is a jumper from PE to N. Some machines have L-N loads, some don't.
I advocate removing the N-PE connection on every machine and providing the N conductor to those machines with L-N loads. I have advocated this from a position of safety, stating that a "potentially lethal shock hazard will exist" should the PE connection to the machine be lost. Another engineer remains unconvinced that this is a legitimate safety issue.
I am looking for precise documentation and examples of how this is really a legitimate safety issue. Can you help?