Removed a Light Fitting Today

[OscarFoxtrot]

Had a plasterer in plastering a ceiling for a customer of mine.

Customer asked me in advance if I could remove the light fitting as they had a new fitting they would put up once plastered and decorated.

Removed the fitting for them and found this

There was another fitting in adjacent room I knew was going to be replaced also, so I decided to remove it too

Tested across the body of the light fitting and neutral and got 240V.

The light predates the current homeowners by a few years.

Whats the reason why I or anyone else changing a lamp never got a shock from this?

 

[Iggifer]

Well, I dunno about you, but I generally don't change lamps with the switch on (unless it's inconvenient for others to turn the fitting off). So I can only assume home owners were doing it with the light off.

I also would hope you had the power off completely to drop it down

Is there no earth and then the supply neutral connected across neutral and live in the fitting?

 

[OscarFoxtrot]

I had the MCB off. No earth (not sure if snipped back or just not present).

As far as I could see the two reds were live in and out (not sure what the proper term is but I would say permanent live), left hand black was neutral and right hand black was switched live.

 

[Iggifer]

Oh, interesting. Must be to do with standing on a chair to change lamps then. They must be rubber footed chairs! Either than or there's no continuity in the earth cables to the fitting. Unlikely to be the case in 2/2, but not impossible

 

[sparkwright]

Even with the lights off at the switch though, the body of the light fittings would be live.

Can only assume the lamps can be put in without having to hold the fitting.

Best check the rest of the property.

 

[Iggifer]

Even with the lights off at the switch though, the body of the light fittings would be live.

Can only assume the lamps can be put in without having to hold the fitting.

Best check the rest of the property.

Yea on first glance I thought it was switch live to the first fitting then off to the second, didn't realise they were the loop. You may not have to touch it to change the lamp, but you'd think at some point somebody would have brushed against it. Or maybe they were CFLs and just haven't failed since installation

 

[kai]

It's a good idea that B6 MCB's are designed to trip out when a lamp fails - this could have saved the owner's life, as the supply should be dead when the lamp is being changed, before MCB is reset after the changeover.

 

[sparkwright]

It's a good idea that B6 MCB's are designed to trip out when a lamp fails - this could have saved the owner's life, as the supply should be dead when the lamp is being changed, before MCB is reset after the changeover.

I don't agree.

You'd typically restore the power to know which lamp to change. You'd also want light in other rooms to see to find the new lamp.

 

[winston1]

If you are only touching the fitting and nothing else and your feet are insulated (standing on a wooden chair/ladder) you won't get a shock for the same reason birds don't when perched on high voltage cables.

 

[Iggifer]

It's a good idea that B6 MCB's are designed to trip out when a lamp fails - this could have saved the owner's life, as the supply should be dead when the lamp is being changed, before MCB is reset after the changeover.

I don't agree.

You'd typically restore the power to know which lamp to change. You'd also want light in other rooms to see to find the new lamp.

Quite agree. The only time you'd know which one without restoring power is if it failed on switch on, and that only helps if it's a pendant and not a fitting with more than one lamp

 

[sparkwright]

If you are only touching the fitting and nothing else and your feet are insulated (standing on a wooden chair/ladder) you won't get a shock for the same reason birds don't when perched on high voltage cables.

Would you feel anything at all?

 

[winston1]

If you are only touching the fitting and nothing else and your feet are insulated (standing on a wooden chair/ladder) you won't get a shock for the same reason birds don't when perched on high voltage cables.

Would you feel anything at all?

No.

 

[sparkwright]

Hard to imagine sometimes. I mean, far as I know I wear rubber soled shoes and all that, and yet feel a shock, so would expect to standing on a wooden chair.

 

[Iggifer]

Hard to imagine sometimes. I mean, far as I know I wear rubber soled shoes and all that, and yet feel a shock, so would expect to standing on a wooden chair.

I was thinking this too. Not that I've ever given myself a shock.

 

[OscarFoxtrot]

Both lights had halogen lamps fitted, the first was 50W GU10's and the second was a style I'd never seen before. According to the homeowner both needed replaced often. You could replace the GU10 without touching the body of the light but I would think you would hold it whilst twisting the lamp.

I had an electrician in a few weeks ago installing new circuits for a kitchen install. I'll recommend they have an EICR carried out for the rest of the property