Electrical Problem in old garage/shed

[CobyRupert]

"I put the tester across the fuse itself as it comes through the wall from the pole and also put it across the switch on the wall farther down the line. I guess that's the load side. I get 30v. "

Now I'm confused. Are you saying you put one probe of the tester on one end of the fuse, and the other probe of the tester on the other end of the fuse and got 30 volts?

When you say "across the switch" and got 30V, what did you put the probes across?

 

[jefwyn]

I'm sure you are not doing this, but just in case, I'll put this out there. I have seen guys, and might have done it myself, read the voltage, not noticing that it was milivolts.

 

[Pete Judd]

Jefwyn, I also have a high end auto ranging meter and you can't watch that decimal point. Bit me a couple of times.

 

[uglyboywith11fingers]

I'd be suspect of a 30 volt reading across the fuse...
if the fuse is good, there should be essentially zero voltage drop across it, current flow or not.
if the fuse is blown, there should be 120 volts across it if the rest of the circuit is complete, ie. switch is on, bulb is good. if circuit is not complete, should read close to zero across the fuse.

you need to read the voltage between the 2 wires that come into the building.

 

[KennyG]

I'd be suspect of a 30 volt reading across the fuse...
if the fuse is good, there should be essentially zero voltage drop across it, current flow or not.
if the fuse is blown, there should be 120 volts across it if the rest of the circuit is complete, ie. switch is on, bulb is good. if circuit is not complete, should read close to zero across the fuse.

you need to read the voltage between the 2 wires that come into the building.

I thought he meant across the lines AT the fuse. We're all guessing at this point aren't we. :laughing:

 

[grsthegreat]

Need to remove fuse and run a ohm test on the fuse.

Or do as Mace suggests and test real voltage between neutral and line side of fuse. (thats the incoming power before the fuse)

In the past i have gotten fake ---low--- readings like 30 volt or 60 volt on systems that had lost the neutral, but got a partial return voltage thru the ground . This voltage disappeared when i removed all light bulbs from their sockets, and unplugged all outlets. After the neutrals were repaired..all was well again.

Also you need to check voltage where power originates at main panel or house.

 

[radioman]

first of all -- you have what its called a voltage drop. either using too much or too far. you need to pull the fuse and measure the voltage at line in connection at box in garage. 120? good. you know line from garage to second pole is likely good. this likely means you have a burnt line or plug or short in extension or fuse connection issues. do you see any deformed or wrinkled appearance of metal fuse connectors? no? with fuse pulled - check ohms resistance of line going to rest of garage. is it open or closed? closed? I'd start investigating the lines in garage and unplug everything in sockets and pulling bulbs and recheck. still closed? then you got bigger issues. its time for a rewire IMHO. I bet once you replace the wiring to everything in the garage- you will find the culprit and you will prevent any future fires from other wiring.
One other thing to check - do you have any junction boxes in your garage? with fuse pulled - I'd start checking and retighten the junction connectors or find a way to eliminate it. A loose wirenut can cause same issue you are having.

 

[Gunny]

Along the line of checking any junction boxes for loose connectors - are there any splices in the lines between the house and the shed? A lot of the old splices amounted to twisting the wires together and taping over them. Very easy to have corrosion build up in them and weaken he conductivity.

 

[Mace Canute]

Along the line of checking any junction boxes for loose connectors - are there any splices in the lines between the house and the shed? A lot of the old splices amounted to twisting the wires together and taping over them. Very easy to have corrosion build up in them and weaken he conductivity.

X 2. :thumbsup:

I wish the OP would come back and give us some more information on what he found.