How safe is it.

[sk]

Hi folks

We recently bought a house. Today my wife bought some plastic backfits for the switch panels that can be fitted without removing the panel. As I was fitting them, I tested the screws that hold the panel to the box in the wall. The tester glows. It made me check all the switch panels in the house and on some of them, the tester glows but rest are ok. Infact we did a paint job over these walls recently. Nothing untoward happened.

I happen to have a cheap digital multimeter. I never used it till today. Read the manual and checked the culprit screws duly. I am not an electician by training or by imagination. I can fit a switch or a light fitting if it comes with two holes for two wires

Now I am worried whether it is dangerous. When I tested with the multimeter, it only gives about 1 volt. I am not even fully sure if my testing is right.

What do you guys think is the best way forward for me?

Is it normal for there to be a feeble voltage at the screws of the switch panel?

The house is built in 1930s, in UK. Electrical work seem to have been updated as the control panel has the trip switches and RCD etc.

Ta
sk

 

[Dellsmp]

Any house purchase should have a periodic inspection report carried out as part of the sale procedure, I'd advise you to contact a local, registered electrician and ask for a PIR, it'll cost between £150-£400 depending on a lot of factors, but will tell you exactly what state your wiring is in and whether it complies with any regs and what needs doing.

 

[Lectrician]

Did you put one probe from your meter to the screw, and another to a radiator or similar??

This could be a lost earth on the lighting circuit, this would lead to induced volts in the earth (or mains volts during a fault!).

I would get this checkes asap - get a loop impedance test done.

If you wanna do it yourself - look for loose earth wires in the light switches/lights.

No sockets etc are affected??

 

[sk]

some of the sockets are affected. Some are ok.

I remember touching some of the screws purposely to see if they give any shock. My son came down from upstairs crying with a burn on his hand. It later transpired that he burnt his hand on the low set halogen light.

I know touching it to see if it is going to electrocute me wasn't a good idea but I was more worried about my son , caution to the wind

It didn't however shock me when I touched them.

I am going to get it checked ASAP.

Ta
sree

 

[sparkythespark]

it can take less than 0.5 of an amp to kill you. would you put your hand in the fire to see if it was hot. or use a lighter for a gas leak. Get it checked out ASAP.

 

[sk]

I know. Iknow.

I am getting a local sparky to get it seen. Infact after seeing your message, I went and rechecked with a radiator connection to the multimeter. The voltage is not stable at all. It seem to hover between 0 and 4-5 volts.

Any rough idea on what causes these kind of probs?

Could it be as Lectrician said, a defect with earthing or something. Thinking about it, I recently installed a chandelier. It came with 3 wires but the ceiling rose only had two wires out, live and neutral. I connected the lamp to only earth and neutral and left the earth out. I ope that hasn't caused the problem.

It probably hasn't as this problem persists, even when I switch off the lam I installed.

Ta
sk

 

[Lectrician]

Sounds like your lighting circuit doesn't have an earth.....although for the screws to float at a potential, they must be connected to a conductor which 'can be induced'. This makes me wonder if some parts are earthed, others not, some bits disconnected...........

 

[Stoday]

Sounds like part of the electrical installation was updated and part was not.

CPCs became required in lighting circuits in the 1960's but RCDs were not then available. (voltage operated ELCBs were used).

 

[sparkythespark]

you said you connected the earth and neutral to the lamp is this a
mis-ype or not. wheres the live gone to?

 

[sk]

A Typo. Not earth and neutral. It is Live and Neutral

Earth is just folded nd taped.

Ta
sree