Conduit as equipment grounding conductor
Conduit as equipment grounding conductor
(OP)
NEC allows to use a rigid metal conduit as equipment grounding conductor. Please advise where I can find information on electrical properties of conduits to estimate, say, 3" trade size conduit body conductivity and determine what would be AWG size of the corresponding copper equipment grounding conductor.The practical situation: at one of installations contractor forgot to pull equipment grounding conductors along with power wires (isolated DC system). It is impossible to add (pull) new conductors, so we are considering bonding both ends of the conduit and using it as a grounding conductor. Normally, we would use,say, AWG # 4/0 wire as equipment grounding conductor. Now we need to evaluate would the conduit be an adequate replacement.






RE: Conduit as equipment grounding conductor
RE: Conduit as equipment grounding conductor
RE: Conduit as equipment grounding conductor
Table 16:
MINIMUM SIZE OF CONDUCTORS, METALIC CONDUIT OR ELECTRICAL METALIC TUBING FOR BONDING RACEWAYS AND EQUIPMENT.
(EXCERPT)
Rating or Setting of Overcurrent Device in Circuit Ahead of Equipment, Conduit, Etc.
Not Exceeding 2000 Amperes
copper-0000, aluminum-350 kcmil, Rigid conduit-not listed, E.M.T. not listed.
Rating or Setting of Overcurrent Device in Circuit Ahead of Equipment, Conduit, Etc.
Not Exceeding 1200 Amperes
copper-000, aluminum-250 kcmil, Rigid conduit-6", E.M.T. not listed.
Rating or Setting of Overcurrent Device in Circuit Ahead of Equipment, Conduit, Etc.
Not Exceeding 1000 Amperes
copper-00, aluminum-0000, Rigid conduit-4", E.M.T.-4"
The 2006 Canadian Electrical Code allows conduit to be used for bonding.
Table 16 no longer lists conduit sizes.
The notes on the rules state that when conductors are installed in conduit the conduit shall be deemed adequate for grounding.
This would appear to be in harmony with the NEC as suggested by davidbeach.
respectfully
RE: Conduit as equipment grounding conductor