ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Reverse Polarity in Europe

For those unfamiliar with the modern style of European ES holder here is an example:



As has been said above, the screw shell doesn't make contact with the circuit until it's screwed right down into the holder.

As 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.

One point that used to be of concern though is the bedside or tablelamp which incorporated a switch at the holder. 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.

Back in the "old days" though, such lamps were commonly wired with twisted twin flex with no polarity identification. 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.

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.

[This message has been edited by pauluk (edited 05-18-2003).]

I know one of our friends from the British Isles mentioned BC lampholders where you couldn't even get hurt by putting your finger in the lampholder. That is, all live parts are shrouded in some way.

Perhaps it is time for all of Europe to switch to this style? Sure, you can make substandard bayonet cap lampholders too, but if they are properly made they are significantly better than the Edison design.

We Europeans can't make things as cheap as the Americans, so let's make them better instead. The BC lampholder is a British, thus European design...

Let's outlaw BC bulbs with more than 100W and require all holders to withstand a 100W bulb. More powerful bulbs should not fit a standard lampholder. Far less risk of fire, at a very low cost.

The simple rule:

Pull the plug before you stick your fingers into anything that is potentially live!

Relying on switches which should be on the hotwire only is just dangerous.

I always take precautions when changing light bulbs and if I need to work on a light fitting I would never rely on switching. 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!

As 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). The socket, however, was wired in reverse so remained live and the guy got 230V up the arm.

Generally, regardless of polarity, even if the switch is on the neutral an applience can be switched off safely.. i.e. it will stop and no longer be pose any risk but anyone working on an applience should ALWAYS pull the plug.

On another point, I know someone who got a shock from from a live neutral cable in Spain. Old 127 - 127 system.

Off topic point:
How are central heating systems usually connected elsewhere?

Here it's normal to do one of the following:

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.

Newer installations have a double-pole switch (fused at 5 amps usually) feeding through to the boiler and pumps hardwired using waterproof glands.

[This message has been edited by djk (edited 05-18-2003).]

>Pull the plug before you stick your >fingers into anything that is potentially >live!

I ALWAYS carry a voltstick & a socket tester (cheapo plugtop with LEDs) after our Electric Board (best quote) put in a new disconnect and wired one phase upside down.

Chris

djk said...

"How are central heating systems usually connected elsewhere?"

This May, I discovered that my parents' system [Lancastrian (UK) central heating/hot water on demand (gas)] was on the kitchen lighting circuit - the very last breaker that I threw!

Hardwired on a simple 10A circuit, probably the one for bathroom lights and receptacles. Either NYM or flex conduit sticking out of the wall (if an electrician did it) or simple round flex (yep you guessed it, plumber was here) sticking out of the wall. I've also seen them on the dedicated 16A circuit for the washing machine. In larger new houses or where all the wiring is redone they'd probably be on a dedicated 10A circuit.
Did I already mention I hate plumbers doing electrical wiring?

Over here in Ireland if it's a gas-fired heating system the gas company lays down very rigid rules regarding installation.

Gas fired system will always be wired to a 10amp dedicated breaker and have a local 2-pole isolating switch that isolates absolutely everything including any remote timers/thermostats/controls.

If it's an oil pressure jet system, soild fuel or "Calor Gas" (LPG) things tend to get done differently.

I was talking the typical 15 or 18kW natural gas combi boiler. Unless it's a complete remodel the plumbers who remove the old gas water heater to install the new boiler will just tap into the next available power line, sometimes they get into a receptacle, but sometimes if you're less lucky they also cut a line, splice it in the middle of nowhere and plaster it over. From their splice they'll usually just nail 3x1.5mm2 flex onto the walls. Another plumber I heard of ran the wire horizontally froma receptacle at 80cm from the floor and then up to the boiler, along with the water pipes. When my uncle installed new pipework he hit the flat cable phase to ground and everything went dark.
As paranoid as the gas guys are concerning the gas lines, the boiler and the chimney, they don't care for the electrical part at all. Many plumbers even have an electrical license for side jobs, but I doubt their wiring is any better (I've seen some examples of plumber sparky wiring, for example Schuko receptacles without a box, just in a hole in the wall, no ground anywhere. Or the washing machine cord sneaking through a hole into the adjacent room (Had some pics in the violations forum some time ago). Or the 1mm2 wiring fused with 16A slow Diazed.)

In England, the electrical feed for oil/gas furnaces varies.

New properties in which the central-heating has been installed during construction may well have a separate dedicated circuit.

In retro-fit heating (and some new) it will quite likely be fed through a fused spur unit from the nearest ring circuit. Sometimes the cord from the back of the unit is just connected to a normal BS1363 plug and plugged into a single outlet, fitted nearby and wired into the ring or as a spur.

I've seen some where the installer ran the flexible cord up through the back of adjoining kitchen units and to the nearest existing receptacle!

As Hutch said above, you sometimes even find the unit tapped off a lighting circuit.

Plumbers doing electrical work? Don't want to think about it. I've sorted out too many screw-ups with the thermostat, control wiring.

We had a guy manage to wire the live terminal to the case of a timer!!!!