polarity of e14 and e27 lamp holders

[beatboaby924y]

In GN3 (2.7.12) it states polarity must be checked at the centre contact of screw type lampholders except E14 and E27.

Anyone know why?

Thanks in advance.

 

[SirKit Breaker]

In GN3 (2.7.12) it states polarity must be checked at the centre contact of screw type lampholders except E14 and E27.

Anyone know why?

Thanks in advance.

Its to do with the construction of the lampholder. If they are wired up incorrectly, there are no exposed live parts accessible.

If you wire a screw type pendant wrong it is a lot easier to touch live parts.

Cheers...........Howard

 

[Marvo]

except E14 and E27.

As Howard says the reg is to prevent the main cap which can be contacted by fingers being a live part. I can't imagine why they would exclude E14 and E27 from the polarity requirements. These are the most common edison screw fittings so why even bother with the reg if you exclude these.

 

[IzzyS]

I though it said something along the lines of "Except for E27 and E14 to BS EN 60238....every edison screw lampholder should be checked for polarity"


Accidental touching of the threaded base of the bulb (or for the pedants glass bulb, filament and connector and other miscellaneous bits that go into making a "light bulb" ) when it's wired reverse polarity would probably hurt....

As I understand it, the BS EN 60238 ones are safer in some way.

 

[snowhead]

Quick Google reveals that BS EN 60238 have a plastic shroud / thread that stops finger contact whether it's live or not.

 

[SirKit Breaker]

Quick Google reveals that BS EN 60238 have a plastic shroud / thread that stops finger contact whether it's live or not.

Thats what i was getting at.