ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades My new electric kettle

Ahh yes, the scraping Earth connection.
The IEC connector took care of that idea.
Kettles over here had much the same thing until about 1992, Reyrolle plugs with the scraping earth contact were banned in 1998, even though they are still used in industrial places for welders (3 phase 400V).
It became illegal to own or sell them in 2000.

Except for the outside earth screw terminal the old connector looks remarkably similar to that used in Continental Europe well into the 1970s. Originally intended for hot appliances like hotplates, irons, toasters, heaters,... it was used for virtually anything, particularly vacuum cleaners but also floor polishers and a load of other appliances (I think I've even seen an oscilloscope with such a connector). 5mm pin diameter, pin spacing 20mm.

I've seen that on plenty of old appliances in Ireland. In fact, I think we have an old Nilfisk Vacuum cleaner that has one.

It was definitely common on things like hot plates, grills, sandwich toasters etc.

I have never seen the version above, with the external earth cable though. The examples I have seen here, had a normal internal earth and two scraping contacts on the edge of the socket. The 'plug' was recessed in the appliance, or shrouded. Similar kind of set up to schuko, just smaller.

And also, an old (1970s) vacuum with two blade pins at arranged at a 45 degree angle i.e. / / but in the same configuration as above.

I have also seen appliances with what looks very much like a "Europlug" CEE 7/16 fitting.

The IEC 'kettle lead' that we find on the back of PCs etc seems to have replaced all of these fittings.

Interestingly, I had a Bosch fridge-freezer which had an IEC plug on the back! It was contained in a connection box on the back. To remove the plug you had to open the screws and open a door on the box.

I can only assume they must have done it this way to allow for easy localisation with the correct cables for 'weird countries'

That's the old UK kettle lead (Also used here) :



Oddly enough, it seems to mate with CEE 7/7 and CEE 7/16 plugs! It's weird how often that same pin configuration got used!

The live and neutral terminals are the two round holes, and the earth is the rectangular hole at the bottom. The other round hole is just a screw for holding the thing together.

These seem to have disappeared by the late 1970s and were very much associated with non-automatic kettles i.e. the type that would just boil until they boiled dry! It was common enough to walk into your kitchen only to find the entire room filled with steam and the wall paper peeling off !!!

I think they may have had some kind of safety cut out, but they certainly didn't seem to have the usual auto-switch off once boiled.

That was used by Electrolux.

The two round pin connector with scraping earth contact was common here for flip down side toasters, irons, electric jugs and frypans. However, I've never seen one with a switch before.
The other purpose I've used them for is plugging in the occasional European appliance; the pins are the same spacing but the grip isn't the best.

Dave,
The older kettles over here had a mechanical device that would eject the plug, if the element went over a given temperature (as would happen if the kettle actually boiled dry).
This device was built into the element itself, it wasn't part of the kettle body.
This was also back when you could actually replace the element in a kettle, instead of throwing the thing out and buying another one.

Oddly enough,
If I recall correctly, the Nilfisk/Tellus vacuum cleaners had a 2 pin "plug" on them as well using vertically orientated pins ie: | |
One thing I never understood was how a metal bodied vacuum cleaner could get away with not being earthed, OK so the motor was double-insulated, but some cleaners had RFI capacitors that were connected to the frame of the appliance, what say one of them decides to go short circuit?

The pins of the UK kettle connector seem to be 5mm in diameter rather than 4.8 (Schuko) but that's not much of a difference.

I don't think they actually fitted any kind of safety cutout unless there's something like a thermocouple inside the element which shuts off power at say above 120 degrees.

The IEC hot appliances connector is slightly different, it'll fit a computer, but a computer lead won't fit a hot appliance since it lacks the side notch between the line and neutral terminals.

I have to correct my last posting, the old "iron connector" had 6.5mm pins, not 5mm (measuring the holes of the female connector is easier but gives false reading). Pretty easy to tell why Schuko plugs don't fit too well. I even have an adaptor which converts an iron lead to an ungrounded extension lead (6.5mm pins and 4mm holes).

Some slide projectors had a predecessor to the IEC plug with parallel flat pins and scraping earth contacts.

Switched iron connectors were fairly common for vacuum cleaners without an integral switch, heat dishes and other appliances. Replacements are hard to find but still in production. I'd like to know why it has been phased out, perhaps due to the overall size and the fairly large holes.

Almost 20 years on I still own this kettle. It didn't get much use after I finished school in 2006 and eventually I discovered that the rubber washer between the element and the body leaked like a sieve. Now I finally got around to sourcing a set of new (old stock) washers. A UK company sells new sets at a very reasonable price but postage to the EU is atrocious (something like £ 2 for two washers and £17 p&p) so I decided to take a chance on a NOS set from Ireland at a much more reasonable 3.50 p&p. There are two element sizes, 1 9/16" and 1 11/16 and the packaging claimed the washers fit both. Turns out they don't but I managed to make the rubber washer fit with a bit of stretching and the old fibre washer was still OK. The price sticker on the bag looks like it's got Apr. 91 printed next to a price of 40 p.

Sometimes you can find things like this at a plumbing supply, locally. I know the O ring used on the steering tube of most outboard motors is a Danco part. Bought from a boat dealer they are a couple of USD for one in a little plastic bag with a part number on it but you can get 10 for less money at Home Depot. (Home owner building materials shop)

I briefly considered checking plumbing supplies but I'd have to find a matching pipe thread size first, which might be difficult (European pipe threads are Whitworth and the nominal sizes are based on the ID of the pipe, so it's not exactly a straight comparison to a thread with known OD). Might be worth taking calipers to the DIY store if the new washer fails again but I hope it will last a while, the old one might have been the original one from the 60s.
Curiosity got the best of me and I checked, 1 1/4" rubber washers could fit a 1 11/16" thread with a bit of stretching. The one thing I'm not 100% sure about is the temperature rating of pipe fittings - household water pipes rarely see temperatures exceeding 60 C, whereas a kettle has boiling water.
And yes, I appreciate the irony that all-metric Europe uses Imperial pipe threads from the mid-19th century. I've never found any evidence to support my theory but I suspect the back story is that British companies built gas works including all the distribution systems and pipe work all over Europe in the second half of the 19th century and once gas pipes used Whitworth threads it made sense to use those for water too. The Germans tried to metrify the nominal sizes without changing the actual threads a few years ago but obiously those numbers are so unwieldy no one actually uses them. The only ugly exception to this rule is tap aerators, which are M24 fine thread if I remember correctly. Deceptively similar in size to 1/2" Whitworth but obviously not the same. That's why you can't connect your washing machine or dishwasher to your sink taps without using an adaptor (or use taps meant for appliances and garden hoses for your sink).

It is not unusual. American NPT pipe sizes are based on the nominal I/D too. Tubing is generally based on O/D so 3/4" "pipe" is actually slightly larger than 1". Copper pipe uses a thinner nominal wall size so 3/4" copper pipe is the same OD as 7/8" "tube".
I have always been curious about European pipe sizes tho. I have some surplus Russian/E German gauges with a strange thread size but it is straight thread, not tapered so they must use a gasket. It is close to but not exactly 1/2" NPS (~0.84")