Voltage Problem - Lighting Circuit

If you're not comfortable (i.e. experienced) with electrical work, consider hiring an electrician. I see 'work' like that all the time, done by someone who thought he was capable. Your peace of mind is worth something.
 
Terrible wiring, voltage drop not tripping the breaker is probably an indication of a poor wire connection increasing the resistance as others have indicated. A few notes; Typical current carrying wires "Hot" side for residential AC wiring is always black or red (usually 2nd leg in single phase 240VAC or switched leg in a 3 way switch) insulated wire. White wire is always neutral (unless marked with electrical/colored tape at each end), which is bonded to earth at the main panel only. Green or bare copper wire is always ground. Romex is fine in an enclosed wall or ceiling, I do not see any need/cost for shielded cable if local electrical code does not require it. Romex needs to be secured with manufacturer approved staples (I prefer the plastic ones) at least ever 4 1/2 feet or less, 12" within a box or receptacle when secured, or 8" if not secured at the entry point into the box. An accessible box is needed for any junction.
 
mksj said:
voltage drop not tripping the breaker is probably an indication of a poor wire connection increasing the resistance as others have indicated.
Click to expand...
There is no way for the breaker to know that part of the voltage drop is across a bad connection and not all across the load. Breakers detect excess current. Bad connections result in reduced current (and heat in the bad connection). An arc fault interrupter *might* have detected this, if the bad connection was arcing.
 
Like Jon said, you might want to replace the lighting breaker with an AFCI. It might save your building in the short term. You might need the AFCI for the rewire work anyway depending on the local building codes.
 
Thanks Toolmaster for the diagram. That is how it was. I revised the one in the first post.
And the verdict is (possibly) Bad connection at wire nut. The neutral leg running over to the 2nd fixture was loose. (Red Arrow)
Must have hit the box just right with the shopvac to knock it loose. The three wires were just placed together in the nut and it did not take
any twisting at all to remove the nut. On the two 'HOT' wire nut connections, the wire were somewhat twisted together.
The neutral wire at the first fixture was also hosed. (Blue Arrow)
Re-did everything, ran a new hunk of romex over to #2.
Garage was framed out of rough cut 2X's, and man they get hard as they age. Makes putting staples in very difficult.
P1080108r.jpg
 
And electrical question. I mounted the fixture and turned on the power. When I take the non-contact detector/indicator and get close to the
body of the fixture (~1") it starts beeping like it's hot. This is all around it. Bad fixture or just so many hot leads inside it?
At that point last night I threw the breaker and packed it in for the night.

Thanks gang for all the replies and help!
 
Probably too many wires. Some of those testers only need about 50 volts to trigger but they shouldn't show anything on a ground or grounded conductor. They will show power on an open neutral. If in doubt check with a real meter from the fixture to a known ground away from the light. The lamps will also trigger a response.
 
John Hasler said:
There is no way for the breaker to know that part of the voltage drop is across a bad connection and not all across the load. Breakers detect excess current. Bad connections result in reduced current (and heat in the bad connection). An arc fault interrupter *might* have detected this, if the bad connection was arcing
Click to expand...

That is what I stated. My point is either it shorts and trips the breaker, or there is a bad connection which could heat up and could cause a fire. An Arc fault would most likely not detect this if there is a measured voltage drop, unless the connection heats up to the point of melting/burning the contact which could lead to arcing. AC lines can also generate phantom (ghost) voltages in wires running together, you often need a LoZ voltmeter/multimeter (low impedance) to measure AC voltages correctly. "Ghost voltages occur from having energized circuits and non-energized wiring located in close proximity to each other, such as in the same conduit or raceway. This condition forms a capacitor and allows capacitive coupling between the energized wiring and the adjacent unused wiring."
 
+ since you are using fluorescent bulbs that have coils anything is possible...throw them away and get leds....they are nice and bright.use even less power... i just did the whole house...always hated the fluoro's...had 3 catch fire
 
i am wondering if you have a bad ground on the whole system....put on some rubber gloves and check the wire from main box to water pipe or ground rod....if you have a bad ground the power that goes through anything livens up the whole ground circuit....
 
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