We have a building that is 60 wide and 100' long running east and west with (5) 20' bays and garage doors.
The owner want to install (4) 2 lamp t5 Fixtures 120v fixtures in each bay for a total of 20 Fixures and switch them 10 and 10 North and south.with (2) 3 way switches at each end of the 100' run.
The fixtures draw 1 amp a piece so we figured on doing this with (2) 20 Amp 120v circuits 10 amps per circuit.
When we started figuring the voltage drop we came up with needing #10 for the 2 circuits.
Problem is with the 2 3 ways at each end of the run, you end up with 2 hots down,4 travelers back, 2 switchlegs back down, a neutral and a ground. 10 #10's which is more than what we want to deal with in a 3/4" conduit.
I was thinking on putting in 2 seperate contactors above the panel and just running the 2 circuits through them to the fixtures running #10 in a 3/4" conduit east and west which would be 2 circuits a neutral and a ground along with a circuit and a neutral for the Emergency lights we have to pick up . and runniing the branch conduit North and South in #12 to each bay of lights.
Then run the 2 3way switches through a seperate 1/2" pipe out of the contactor enclosure to the (2) sets of 3 ways with #12's since we would only be dealing with the coil load.
My partner questioned 2 things.
#1 he mentioned if we reduced the wire size from the #10 in the trunk line to #12 on the branch to the fixtures, someone could come along later, see the #10 in the panel, upsize the breaker to a 30 Amp, then the #12 would not be protected an
#2 he questioned the control for the 2 contactors being in a seperate conduit from the circuits they were controlling.
Does #1 hold any merit? I cant see having to run #10's all the way to the light fixtures. this is a large increase in material and wire cost.
also #2 is there any violation of running the control for the lighting contactors seperate from the conduit that has the lighting circutis?
I dont know of any.
Just trying to keep the runs in 3/4" with least amount of wires possible, but still do it correctly.
Thanks in advance for any suggestions.
JAP>
The owner want to install (4) 2 lamp t5 Fixtures 120v fixtures in each bay for a total of 20 Fixures and switch them 10 and 10 North and south.with (2) 3 way switches at each end of the 100' run.
The fixtures draw 1 amp a piece so we figured on doing this with (2) 20 Amp 120v circuits 10 amps per circuit.
When we started figuring the voltage drop we came up with needing #10 for the 2 circuits.
Problem is with the 2 3 ways at each end of the run, you end up with 2 hots down,4 travelers back, 2 switchlegs back down, a neutral and a ground. 10 #10's which is more than what we want to deal with in a 3/4" conduit.
I was thinking on putting in 2 seperate contactors above the panel and just running the 2 circuits through them to the fixtures running #10 in a 3/4" conduit east and west which would be 2 circuits a neutral and a ground along with a circuit and a neutral for the Emergency lights we have to pick up . and runniing the branch conduit North and South in #12 to each bay of lights.
Then run the 2 3way switches through a seperate 1/2" pipe out of the contactor enclosure to the (2) sets of 3 ways with #12's since we would only be dealing with the coil load.
My partner questioned 2 things.
#1 he mentioned if we reduced the wire size from the #10 in the trunk line to #12 on the branch to the fixtures, someone could come along later, see the #10 in the panel, upsize the breaker to a 30 Amp, then the #12 would not be protected an
#2 he questioned the control for the 2 contactors being in a seperate conduit from the circuits they were controlling.
Does #1 hold any merit? I cant see having to run #10's all the way to the light fixtures. this is a large increase in material and wire cost.
also #2 is there any violation of running the control for the lighting contactors seperate from the conduit that has the lighting circutis?
I dont know of any.
Just trying to keep the runs in 3/4" with least amount of wires possible, but still do it correctly.
Thanks in advance for any suggestions.
JAP>