Quick question about a screw-in domestic light fitting

[alnmcn]

Hi,

A friend has heat lamp in his stable for the animals in winter. The lamp is a screw in type fitting on a pendant cord.

He said, for whatever reason, he touched the bulb whilst it was on but in the process also touched the metal threaded bit on the cap and got a tingle from it (as it is not completely shrouded by the fitting).

I have not seen the bulb but I assume its the type where the live is the contact to the top of the bulb and the neutral is connected via the cap casing.

If this were to be the case, should touching the neutral cause a shock as there is obviously current and voltage passing through?

Just wondered as I thought the neutral was meant to be at the same potential as earth? i.e. 0V

For reference both neutral and earth are provided from the electricity company’s feed.

Thanks.

 

[thompsk]

outer casing is not guaranteed to be the neutral if the rose has been wired incorrectly, suggest you check the rose then repoprt back on what you find.

 

[BS3036]

Well there's two ways round to connect the Edison Screw sockets. The safe way and the other. I remember (in my youth) helping out at a disco, screwing PAR80 lamps into a lighting batten, at the top of a ladder, holding on to a water pipe in one hand and touching the thread of the lamp with the other, assuming that the guy hadn't powered the lamps up yet! I guess that one was the wrong way round, judging by the belt I got!

However I also know from personal experience that neutral can have a sufficient potential difference from earth to give you a surprising tingle.

So it may be wired wrong or it may not be. I don't touch them when they're on anymore!

 

[alnmcn]

Will check the wiring.

Forgot to mension the pendant fitting is actually a bayonet type with a screw cap converter fitted to take the bulb.

Never seen one of these before, can you fit them the wrong way round and therefore cause live to be neutral and vice versa.

i.e. turn it through 180 degrees to correct it?

Thanks.

 

[ban-all-sheds]

Never seen one of these before, can you fit them the wrong way round and therefore cause live to be neutral and vice versa.

Yes.

i.e. turn it through 180 degrees to correct it?

Yes.

But much better would be to replace the lampholder with the correct sort, permanently wired correctly.

And if someone is out there selling products with exposed live parts, I think a report to Trading Standards is in order.

 

[plugwash]

But much better would be to replace the lampholder with the correct sort, permanently wired correctly.

Unfortunately the selection of mounting methods for BC lampholders seems rather different from the selection for ES lampholders so it may be difficult to find a direct replacement.

 

[333rocky333]

most heat lamps would go in a es holder wired with high temp flex ,
This sounds like an adaptor in a bc pendant, and its surprising it has not all been heat damaged.

some new ES holders now disconnect from the cap even the outer neutral once the lamp is screwed out a bit, and the lamp thread is enclosed till this happens, the regs say certain bs ones can be wired any polarity, although I would still use centre pin as live