Sub Panel with no EGC
- Thread starter PowerdT
- Start date
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
No EGC or conduit as EGC?
Yes the feeder is using EMT so all the branch circuit use the EMT as well as EGC
Existing is used Conduit as EGC
So you do have an EGC and I wouldn't worry about it. In most cases metallic conduit or tubing in metal construction is a superior EGC than a wire.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Perfectly acceptable.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Short answer no. You cannot bond the neutral to create an EGC in a sub-panel. As others have noted you do have an EGC run with the feeder in the metallic tubing so that is all that is required.
The reason I mentioned is because I have seen some panels in commercials building with no EGC feeder, but they have green wire bonded to the EMT knockout then to ground busbar inside panel
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Be sure any EGC buses are bonded to the enclosure.
Got i
Got it. What size of EGC wire shall be used to bond? Would that be 250.122 based on 225A #4
- Location
- New Jersey
- Occupation
- Journeyman Electrician
A bonding jumper (the green wire) from a bonding bushing is required if the voltage is over 250 volts to ground and if the panel has concentric or eccentric knock outs. Some guys just like them on everything even when they're not required.
It would be sized according to T250.122 or larger if 250.122(B) comes into play with the feeder.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If the EGC bus is bolted directly to the enclosure, none.
I see if ground busbar inside enclose is bolted to enclosure no need to bond anything. For example, if I have a lighting load to feed I can use 2#12 and 1#12G
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Yes, if I understand you correctly. A grounding bus bolted to the can effectively connects the grounding wires to the feeder conduit.
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
You are talking about adding circuits to this panel, am I correct? You can use a grounding conductor and just bond it to the enclosure. I've even added a grounding conductor buss into a panel and just bonded it to the enclosure
- Location
- Bremerton, Washington
For the types of allowed EGCs see 250.118
To be clear of the plan, I’m replacing the 480V 225A panel and re-routings all the branch circuits. The panel feeder is only 3 hot and 1 neutral, EMT used as EGC.
Even tho EMT is acceptable as EGC and the branch circuits also used the EMT as EGC,. I was in Impression to add #12 to each circuit since the route of the branch circuit is long
- Location
- Illinois
- Occupation
- retired electrician
The calculations will say that the EMT is an effective ground fault path for a longer distance than a wire type EGC that has been sized per Table 250.122.