No, this isn't a "Solve This Service Call", since this one has me baffled.
Went on a call yesterday for a tripping breaker in a house. Fluke 33 read 2.86 amps max, and it was tripping within 2 seconds of turning on. I swapped the breaker out (Siemens 20a), and it held for at least 45 minutes, with 2.23 amps maximum.
"Bad breaker, ma'am. Cash or check?" I wished they were all this easy.
Customer calls late last night, saying the breaker tripped again.
So I head there this morning.... breaker is still in tripped position. I pull the cover off and hook up my Fluke 289 this time. Start recording, then start hunting down what's on the circuit.
The NM comes out of the panel (in a garage) into the basement. Right inside the basement, it splits into 2 runs (yes, there's a box!). One run goes up into the living room, and serves only one duplex for the TV/VCR/DVR. That whole combo pulls 1.2 amps when running.
Other NM goes into a sunroom that was added years ago. 3 receps, two switches, 1 ceiling fan. I pull all the devices and the fan and don't see any nicked wires or grounds too close to hot screws. Nothing that even remotely resembles a problem. One switch in the sunroom turn on the fan light (the fan is on the pullchain), the other switch feeds a post light in the back yard, but turning it on didn't do anything.
After an hour and a half of rooting around this hoarders' house (not packed to the rafters, but the floor is there somewhere), I finally gave up. Told the HO to see what happens.
I shut off the meter, saved the data, and here's what it looks like:
Went on a call yesterday for a tripping breaker in a house. Fluke 33 read 2.86 amps max, and it was tripping within 2 seconds of turning on. I swapped the breaker out (Siemens 20a), and it held for at least 45 minutes, with 2.23 amps maximum.
"Bad breaker, ma'am. Cash or check?" I wished they were all this easy.
Customer calls late last night, saying the breaker tripped again.
So I head there this morning.... breaker is still in tripped position. I pull the cover off and hook up my Fluke 289 this time. Start recording, then start hunting down what's on the circuit.
The NM comes out of the panel (in a garage) into the basement. Right inside the basement, it splits into 2 runs (yes, there's a box!). One run goes up into the living room, and serves only one duplex for the TV/VCR/DVR. That whole combo pulls 1.2 amps when running.
Other NM goes into a sunroom that was added years ago. 3 receps, two switches, 1 ceiling fan. I pull all the devices and the fan and don't see any nicked wires or grounds too close to hot screws. Nothing that even remotely resembles a problem. One switch in the sunroom turn on the fan light (the fan is on the pullchain), the other switch feeds a post light in the back yard, but turning it on didn't do anything.
After an hour and a half of rooting around this hoarders' house (not packed to the rafters, but the floor is there somewhere), I finally gave up. Told the HO to see what happens.
I shut off the meter, saved the data, and here's what it looks like:
The spike on the left is when I checked the amp reading on the main line coming into the house, just to make sure it was reading amperage correctly... then I clamped onto the branch circuit where the highest peak after that is about 2.5 amps.
Other than the possibility of a buried box, I exhausted my storehouse of experience on this one. I'll admit.... this one got me.
Other than the possibility of a buried box, I exhausted my storehouse of experience on this one. I'll admit.... this one got me.