2volts on a disconnected cable?!?

[simo1991]

I've recently been sent to complete a re wire for another contractor and there is a cable which isn't connected to the consumer unit which shows 2volts on it! is there a reason for this? I'd it potentially dangerous? How can I correct it? It's on one leg off the ring main in the kitchen. Any information would be appreciated I've tested it with my digital multi meter and done a insulation resistance test on IT also which shows its all fine.

 

[davidjones89]

I've recently been sent to complete a re wire for another contractor and there is a cable which isn't connected to the consumer unit which shows 2volts on it! is there a reason for this? I'd it potentially dangerous? How can I correct it? It's on one leg off the ring main in the kitchen. Any information would be appreciated I've tested it with my digital multi meter and done a insulation resistance test on IT also which shows its all fine.

I had this once, completely dead cable with no connections, cable was slightly damp with it not being used for donkeys so put it down to corrosion on conductors becoming acidic and generating slight voltage, could of been wrong but no other reason for it

 

[simo1991]

Yeah I thought it could be damp as the house is a shell but the cable is new and was roughly put in about 3weeks ago?

 

[ayjay]

its probably running alogside a live cable
and acquiring induced current from it

 

[Darkwood]

Inductance - ... run any unshielded cable alongside a live cable and you will induce a voltage ...At 2v I think your overthinking this one tbh.

 

[simo1991]

It's just something I've never seen before and as its my first job on my own I'm paranoid o get everything spot on. So basically I'm just getting a induced voltage off another cable? And seem as its only 2volts this won't cause any problems?

 

[Darkwood]

Stick a 9v battery on your tongue and then realise what 2v will achieve ... think SELV and what the voltages are when classed as SELV/PELV, we all been there so just push this worry aside and move on to 'have you tightened the terminal correctly'

 

[simo1991]

Haha cheers mate. Rather ask then just worry about something thanks once again

 

[ayjay]

my now dead grandma had an old radio that had a drycell battery
and a 4 pin plug
one side was 87 and a half volts tother was 3 volts for the heaters in the valves
quess who stuck his tounge on the old so called flat battery terminals
ME
never did that again

 

[PEG]

Simo,presuming you are capable of safe practice,get yourself a roll of t&e,identify and open conductors at BOTH ends. Connect L and N at one end. Measure voltage at other end L/N. Now measure voltage cpc/N. If possible,measure again using a REAL meter. The difference between the results should tell you two things,one regarding the phenomenon,one regarding testing apparatus. Do not be seduced by readings on MFT's giving you the FULL story...seen a bus with "Kelloggs" wrote on the side....but it wasn't full of cornflakes...:conehead: Not having a pop,my friend,but have a play.Stay safe,but have a play

 

[davesparks]

I've recently been sent to complete a re wire for another contractor and there is a cable which isn't connected to the consumer unit which shows 2volts on it! is there a reason for this? I'd it potentially dangerous? How can I correct it? It's on one leg off the ring main in the kitchen. Any information would be appreciated I've tested it with my digital multi meter and done a insulation resistance test on IT also which shows its all fine.

Don't use a multimeter to test for isolation/voltage.
Use an approved voltage indicator.

 

[ayjay]

Don't use a multimeter to test for isolation/voltage.
Use an approved voltage indicator.

a neon screwdriver?

 

[Pete999]

Induced E.M.F. maybe?

 

[simo1991]

I've used a voltage tester and a multi function meter. Used both to check if they both show the same reading.

 

[davesparks]

And did the voltage tester register a live voltage or a phantom voltage?

 

[LeeH]

Try an analogue meter.

 

[simo1991]

A phantom voltage.

 

[davesparks]

So if it has registered as a phantom voltage then what is the point of this thread?

 

[PEG]

So if it has registered as a phantom voltage then what is the point of this thread?

...To educate,inform and entertain,or why do we bother? :happy:

 

[Rockingit]

Well that's 30secs of my life reading this thread that I'm unlikely to get back again. Jeez.