dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
754

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

Mapping wires in crawl spaces - Clamp meter or AC sensor

I'm mapping all the wires I can find in crawl spaces, but I cant necessarely follow them to an outlet or fixture.

So by process of elimination, I'd turn turn off a candidate circuit and see if the wire isn't live anymore.

Would an stud finder with AC detection be reliable enough to tell me if a wire is live?

If not, what would be a reliable but affordable clamp meter just for AC detection and a rough estimate of amps? I don't need accuracy on the readings (Except of course for whether the wire is live or not).

Side note - Is it okay to run wires along drain pipes to go up a floor? I'm guessing I'd need RW. There's a drain pipe that gives me a pathway from the basement to the attic and crosses 2-3 circuits along the way.

alphapointe
Don't Touch Me
MVM
join:2002-02-10
Columbia, MO

alphapointe

MVM

A proximity sensor should work... a clamp meter won't work, as it has to be clamped only on the hot wire. Clamping around both hot and neutral cancels out the magnetic field that the clamp meter is reading...

I don't know about running with pipe, one of the sparkys will need to chime in on that...

alkizmo
join:2007-06-25
Pierrefonds, QC

alkizmo

Member

said by alphapointe:

A proximity sensor should work... a clamp meter won't work, as it has to be clamped only on the hot wire. Clamping around both hot and neutral cancels out the magnetic field that the clamp meter is reading...

Ah so a clamp meter only works if I can separate the neutral from hot. I didn't know that (Don't own one yet). Too bad really. I guess I won't invest in a clamp meter as it's not so useful to measure branch load unless I strip part of the jacket.
said by alphapointe:

I don't know about running with pipe, one of the sparkys will need to chime in on that...

Well after I posted that question, I started thinking that if I were to run multiple circuits through that path, I better just run a large diameter raceway with a junction box to branch out at each floor. At that point it doesn't matter that it's close to the drain pipe (Except for the junction boxes).

PVC or EMT is now the question
PVC is annoyingly more expensive when you get to the junction boxes, but it would be waterproof in case of a spill like earlier this week.