Old installations usually had a fused spur feeding a timer feeding 2/3 a sockets (BS1363 or 5amp BS546) connecting into the pumps and burner/boiler. Here it's normal to do one of the following: How are central heating systems usually connected elsewhere?

On another point, I know someone who got a shock from from a live neutral cable in Spain. it will stop and no longer be pose any risk but anyone working on an applience should ALWAYS pull the plug.

Generally, regardless of polarity, even if the switch is on the neutral an applience can be switched off safely. The socket, however, was wired in reverse so remained live and the guy got 230V up the arm. Always trip the breaker or remove the fuse at the consumer unit and test all the conductors at the fitting just to be 100% sure!Īs someone mentioned before a guy working on a central heating boiler here was electrocuted when he switched off the power at the socket (it was connected via a BS1363 plug). I always take precautions when changing light bulbs and if I need to work on a light fitting I would never rely on switching. Relying on switches which should be on the hotwire only is just dangerous. Pull the plug before you stick your fingers into anything that is potentially live! Obviously it would always be advisable to pull the plug before fiddling with the lampholder, but there would always be someone who would assume that because the switch on the holder was off that they could touch the contacts in safety. Even if coded cords were used, many were fitted with the reversible 2-pin 5A plug, making it impossible to guarantee placement of the switch in the hot conductor. These days, they're fitted with the standard BS1363 plug and color-coded cordage making it easy to connect the hot side to the switch.īack in the 'old days' though, such lamps were commonly wired with twisted twin flex with no polarity identification. One point that used to be of concern though is the bedside or tablelamp which incorporated a switch at the holder.

Regarding the exposed section of screw-base.you remember my story about my mom's co-worker (and amateur electrician) in Germany who got himself killed while on a ladder changing the lightbulb hanging from the ceiling in his room.įor those unfamiliar with the modern style of European ES holder here is an example:Īs has been said above, the screw shell doesn't make contact with the circuit until it's screwed right down into the holder.Īs in Ireland, however, the BC lamp is by far the most common in most domestic fittings, and with a symmetrical double-contact fitting polarity is of no importance. Why are Edison fittings the world standard? One word.EDISON. Was half-tempted to climb onto the table and re-tighten the little suckers.Īnd any fool can get themselves electrocuted by sticking their finger into a double-contact bayonet socket also. Was sitting in a coffee shop in Chelsea last weekend and watching the bulbs in the oh-so-trendy goose-neck fixture flicker and dim. You don't get that flicker flicker and arcing inside the lampholder that eventually destroys the center contact of the socket! Why do you think that cars use bayonet fittings for some of their lightbulbs? So, my question is: Why are receptacles and plugs in Europe designed in such manner?Īnother benefit of Bayonet fittings is that the bulb doesn't work itself loose due to vibrations, so it's excellent for use in ceiling fans, trouble-lights, wall sconces etc. Anyway, as we replace a lightbulb, it is possible that our fingers can make contact with the screwshell of the lamp and we can get shocked. If we have reverse polarity at the receptacle, the srew shell on the lamp is now hot, even if the swith on the lamp is in the 'off' position.

Lets take a normal household lamp for example,(just a standard 100w incandescent lightbulb). Here in Italy, the design of the receptacle, allows the plug to be installed in either direction which can result in polarity reversal. appliance plugs are designed to connect to receptacles in only one direction. Reverse polarity is created when the grounded conductor and the ungrounded conductors are reversed when wired to a 120v receptacle/outlet. As we know, reverse polarity is prohibited in the U.S.-according to the NEC (National Electrical Code) and other national standards. Here we go, reverse polarity does not seem to be much of an issue here in Italy.

Lamp cord polarity