30v on disconnected cable?

[BS Barry]

Recently pulling in some new lights in my kitchen, using the original feed in I ran 2 strappers and cables for 8 downlighters.

Turned the circuit on and checked with my volt stick that the switching was correct and noticed the volt stick was going off no matter what position the switch was in.

Tested with a fluke and seen 30v to earth and neutral- even when I'd disconnected the cable?!

Can anyone shed any light on why I might be getting this voltage?

Cheers!

 

[Marvo]

Probably the very high imput impedance of your tester making it too sensitive to capacitively coupled voltages.

Has your Fluke got a 'Low Z' setting?

 

[Marvo]

Dual Impedance Digital Multimeters - https://www.fluke.com/en/learn/blog/digital-multimeters/dual-impedance-digital-multimeters

 

[Charlie_]

Also you need to check the integrity of the cpc

 

[static zap]

Approved voltage testers apply enough "load",
to sort out these "phantoms"!

 

[BS Barry]

Probably the very high imput impedance of your tester making it too sensitive to capacitively coupled voltages.

Has your Fluke got a 'Low Z' setting?

Nope!

 

[DPG]

If the cable is indeed 100% disconnected then it will be picking up a voltage by coupling from another one adjacent to it somewhere, as described above.

 

[BS Barry]

Dual Impedance Digital Multimeters - https://www.fluke.com/en/learn/blog/digital-multimeters/dual-impedance-digital-multimeters

Thanks for that!

 

[MJPD29]

Induced voltage?

 

[Lewis Ashton]

I went to install some spotlights in a house (owner was retired GPO spark). I was getting voltage on the earth. I couldn't understand why until I asked the owner if he had swapped any cable; he told me that he'd replaced a length from the CU to a junction box with, "a second hand, good piece". Swapped this length of cable and the fault went. I stripped the t+e in question and found the insulation of the phase had broken (repeated bending/too tight a bend) and connected with the earth.