kevinb5501
Member
- Location
- Chicago suburbs
A question on a practice test is The 15,20,60A branch circuits running in the same raceway. How many grounding conductors shall be installed for these circuits?
number of grounding conductors needed
- Thread starter kevinb5501
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kevinb5501
Member
- Location
- Chicago suburbs
I am thinkig Two
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
my answer is zero.
kevinb5501
Member
- Location
- Chicago suburbs
thank you, I will read it all that is the way I prefer to learn
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Are you planning to take credit for the conduit, despite the question not telling us what material is used for the conduit?
billsnuff
Senior Member
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- East of 480sparky
newinspector1
Member
- Location
- NC
I say one.
Actually my answer would be one regardless of the type of raceway.
The question did not state "in", just "with".
250.188 lists metallic conduits a "equipment grounding conductors" so the metallic conduit would still be one.
The question did not state "in", just "with".
250.188 lists metallic conduits a "equipment grounding conductors" so the metallic conduit would still be one.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Since we are not given whether the raceway is metallic or non metallic then we must assume an EGC. Now after the OP finds out how many, without all you know it alls screaming it out, :grin: then he needs to determine what size(s) the egc('s) need to be.
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
huh? is the green stuff supposed to be the egc?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Conduit Phil
Member
Why would a #10 be too small?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
I have the same question. T250.122 says #10 for 60 amps. What am I missing?:-?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I did say that I was guessing.
The #10 might work. I was factoring in derating and increasing the ungrounded conductor size of the 60 amp circuit which would trigger 250.122(B). Doing the calculation #6 still works.
dwellselectric
Inactive, Email Never Verified
- Location
- Cape Cod, Massachusetts
Now that is kinda random....
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Are you planning to take credit for the conduit, despite the question not telling us what material is used for the conduit?
His question asked how many SHALL be installed. based on the limited information he supplied, the minimum is zero.
However, the code might require as many as one per circuit (think IG circuits). And he did not tell us how many circuits were involved.
Or there might be a spec involved that requires something special.
I had not even considered that the wires are going to need to be upsized if there are more than 3 CCC. However since he has not told us how many circuits of each size there are, there is no way to make that calculation either. Although in context one might assume one of each, the OP does not say that.
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