Checking power on wires

[Kurt63]

Always have been handy and can usually work it out if a problem.  My dad always told me "there is never a stupid question". So here it goes! 
If you need to check the voltage on a wire where there is no way to access either end for the tester, how do you check the voltage without cutting or breaking through the insulation?  Do you poke a hole with the tester lead and tape over? 

Thanks,
Kurt

 

[Jim Godward]

Some of us use a needle or a straight pin to pierce the insulation when there is no alternative and then just leave that small hole, i.e., just walk away and ignore it.  It works for most wiring except for insulated cable like coax, etc.

 

[Kurt63]

Done that in the past.  Was just curious if there might be something else available. 

 

[SeilerBird]

Use this handy device:

http://www.amazon.com/Sinometer-MS8211-Auto-Ranging-Multimeter-Non-contact/dp/B000QE4EPW/ref=sr_1_18?ie=UTF8&qid=1340513045&sr=8-18&keywords=multimeter

 

[Kurt63]

I have one for AC, will have to look at the DC model.  Thanks,

 

[Gary RV_Wizard]

The description of the Sinometer on Amazon says "AC/DC voltage". Any truth to that?


If the wires are loose and individual, any "clamp on" type meter works. Unfortunately, that technology just doesn't work with paired wires, e.g. Romex or lamp cord) or those wrapped in bundles with other wires.

Example:
http://www.tmart.com/Mastech-MS2008A-Half-the-Number-of-Three-Digital-Clamp-Multimeter_p144096.html?utm_source=nextag&utm_medium=referral&utm_term=23000110&utm_campaign=product

 

[SeilerBird]

The description of the Sinometer on Amazon says "AC/DC voltage". Any truth to that?

I don't know if it is true or not. I have an inexpensive Greenlee that only does A/C and it does it very well. It beeps and flashes if it gets near a hot wire. It was part of an inexpensive kit I bought last year:

http://www.amazon.com/Greenlee-TK-30-Basic-Electrical-Kit/dp/B000FCIMFS/ref=sr_1_1?s=hi&ie=UTF8&qid=1340545798&sr=1-1&keywords=greenlee+multimeter

 

[Tom]

The Sinometer works on either AC or sinusoidal DC 

BTW check the voltage before sticking a pin through the insulation of the wire; You might not want to do that if it's 120V.

 

[captsteve]

And if you are worried about the hole corroding, try some liquid electrical tape. It will seal it up pretty good.

 

[Kurt63]

This is more for 12v DC.  Tracing an electrical issue on the MH.  I am very cautious when working around 120v. 

 

[John From Detroit]

Some of us use a needle or a straight pin to pierce the insulation when there is no alternative and then just leave that small hole, i.e., just walk away and ignore it.  It works for most wiring except for insulated cable like coax, etc.

Same here,, When you need to check VOLTAGE, that is the only way.

If you need to test for PRESENCE of voltage, there are other ways, but they won't tell you what the voltage is.. That's the only way to actually get voltage

I normally don't worry about the pin hole, but if it's in a weather exposed area will GOOP it (GOOP (TM) is an adheasive sealant that ... Well I usually buy 2 or 3 tubes at a time) .

 

[Lou Schneider]

The description of the Sinometer on Amazon says "AC/DC voltage". Any truth to that?

Actually, it says:

"The Sinometer MS8211 is a pen-type digital multimeter with non-contact AC voltage sensor, it can measure AC/DC Voltage, Resistance, Diode and Continuity test. Its unique non-contact AC voltage sensor is a great feature for electric inspection..."  [boldface added]

So it's non-contact for AC voltage only - the other modes use conventional connections to the conductors.

 

[Jim Godward]

The Sinometer works on either AC or sinusoidal DC 

BTW check the voltage before sticking a pin through the insulation of the wire; You might not want to do that if it's 120V.

That's why my pliers are insulated.   

 

[Tom]

That's why my pliers are insulated.

LOL Jim, it's also the reason we used to tell folks who insisted on a 'finger test' for a hot wire, to use the back of their finger  ;D

 

[SeilerBird]

That's why my pliers are insulated.   

I had to laugh at that statement. It brought back memories of my days as a house wireman. The main tool we used a pair of Klein 9" pliers. The very first thing we would do would be to remove the insulated handles. It fit a lot easier in the hand and after a year or so would be smooth as chrome. The second thing we would do is cut a notch near the pivot point so the pliers would also work as a wire pulling tool. You could lock it onto a fishtape with ease and pull with both hands. We did remove the insulation however we were working with wires that were never live so there was no chance of getting shocked.

 

[SeilerBird]

LOL Jim, it's also the reason we used to tell folks who insisted on a 'finger test' for a hot wire, to use the back of their finger  ;D

In the 70s as an apprentice I worked a few days with an old timer in his 60s. We went into the attic of an old house with knob and tube wiring. He wanted to test it to see if it was live so he licks his index and middle fingers and touches both wires at the same time. "Yep, it's hot". That is one thing I never did

 

[Tom]

How about this 'hot finger' test (true story) ....

Many years ago (the 60's), while working in a 'low-voltage' substation feeding some 5KV drive motors, a colleague had racked out an oil-filled breaker for maintenance. Following maintenance and before racking the breaker back in, standard procedure was to shove some wires into the "spouts" feeding the cables to the drives, and hook the other ends up to a high voltage insulation tester. This day, the guy wasn't paying attention and reached into the busbar (live) spouts instead. He was lucky that he was merely thrown across the substation, and suffered only a dent in his professional pride.

 

[Jim Godward]

In the 70s as an apprentice I worked a few days with an old timer in his 60s. We went into the attic of an old house with knob and tube wiring. He wanted to test it to see if it was live so he licks his index and middle fingers and touches both wires at the same time. "Yep, it's hot". That is one thing I never did.

Dad used to give me a bad time as I would not do the touch test.  He, on the other hand would do it on both 120 and 240 but NOT on 440!      I believe that he was de-senitized as about 3 months before I was born, he was hit by lightning while on a pole and was knocked to the ground.  Had scars on his hands where the wire and wrench were and on his feet from the climbing spurs.  Ruined his boots and gloves though!

I havedone the touch test but not on purpose!