Hi,
I have an industrial control panel with the following:
dimensions: 600 x 600 x 250mm
Panel feeder : #14 AWG , MC cable PVC-coated , supplied from a main power cabinet (5m away from our panel) ,380 v ac 3-phase , 4-wire : L1,2,3 & N
DC circuits inside : 24 vdc/5A power supply and another 24 vdc/20A power supply
Overcurrent devices 3A (at supply side of first power supply) & 5A (at supply side of second power supply)
the system is ungrounded (the MC feeder cable has NO grounding wire (green/yellow) )
My Questions:
----------------
1) I should refer to Table 250.122 to get the grounding conductor size for each equipment separately (size of each power supply bonding jumper by the of rated current of the upstream circuit breakers mentioned above) , is that correct?
2) what about grounding panel ? I know that all the jumpers will be bonded to the panel-board , then there should be some conductor or rod coming through the panel and fixed to the earth under the panel , correct? how to size that? what section of The NEC mentioned that ?
Thank you in advance
I have an industrial control panel with the following:
dimensions: 600 x 600 x 250mm
Panel feeder : #14 AWG , MC cable PVC-coated , supplied from a main power cabinet (5m away from our panel) ,380 v ac 3-phase , 4-wire : L1,2,3 & N
DC circuits inside : 24 vdc/5A power supply and another 24 vdc/20A power supply
Overcurrent devices 3A (at supply side of first power supply) & 5A (at supply side of second power supply)
the system is ungrounded (the MC feeder cable has NO grounding wire (green/yellow) )
My Questions:
----------------
1) I should refer to Table 250.122 to get the grounding conductor size for each equipment separately (size of each power supply bonding jumper by the of rated current of the upstream circuit breakers mentioned above) , is that correct?
2) what about grounding panel ? I know that all the jumpers will be bonded to the panel-board , then there should be some conductor or rod coming through the panel and fixed to the earth under the panel , correct? how to size that? what section of The NEC mentioned that ?
Thank you in advance