I cut and pasted this from an Israeli electrian's site. Nice to know that everyone has the same problems
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Customer: Hello is that the electrician ?
Listen, the new circuit breakers that you just put in keep tripping. The old fuses never blew !

EDS: Ah ! thats because someone had already replaced the old fuses with coffin nails which meant that instead of the old fuses protecting the house wiring, the wiring was protecting the fuses !

Customer: But it worked and I could run the washing machine at the same time as the dryer, the dishwasher, the stove and all the room heaters !!! Can’t you put a ‘stronger’ circuit breaker in the box ?

EDS: Maybe you should have kept the old fuses and replaced all the wiring instead !

Look, for safety the fuses or circuit breakers MUST be weaker than the wire in it’s circuit. That way if there’s a problem, the fuse will go before the wire starts burning or the the switch contact goes. The thickness of the wiring determines the size of the fuse that has to be installed. There have been countlesss cases of fires in electrical boxes caused by overloaded circuits or faulty fuses.

Customer: So what can I do with my washing machine and dryer ?

EDS: In new flats that are wired correctly, each device will have it’s own correctly rated breaker. In old houses you’ll probably have to run one machine after another or install a new heavy duty circuit from the main fuse-panel to one of the machines. Also, dryers usually have a half-power setting.
(any resemblance to actual customers is purely coincidental !)
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Some interesting information about the Israeli wiring on the site btw:
http://members.tripod.com/~eds_engineering/

Some interesting items on that site. Did you see the part about their PoCo not wanting to provide a single-phase supply over 40 amps?

Yes, I did. I have a standards proposal in this field too, but I'll take that some other day.

C-H,
Seen this God knows how many times,
especially with replacing Pillar Box(Mains) fuses(HRC),with houses protected by RWF sub-
circuits, if it blows again, just put a bigger fuse wire in the holder, most home-owners over here, do not care about Co-ordination of protective devices, hence, the Power board, turning up when the whole house has gone dead.

Sorry C-H,
I have managed to kill another subject.

Don't be shy -- Let's hear them!

I don't think I have posted this before.

Read the EDS article first, to see the background. I have thought of this before: The EDS article speaks of 3x25A, but some countries (yeah, guess which ) use 3x16A.

Got a phone call from a friend yesterday, who had this problem. "The cooker rings aren't working nor is some of the heating." "Replace the broken main fuse"

It's impossible to balance a normal houshold on a small 3-ph system. No matter how you place the dishwasher, kitchen counter sockets, washing machine it only takes someone using the dishwasher, kettle and the oven to blow one main fuse. Sure, you can move them around but the only result is the fuse blowing when the washing machine is used instead.

Now this wasn't so bad if it weren't for the combination of phase-to-phase loads and single pole fuses which means that when a fuse has blown, the voltage is dancing around uncontrollably. When you turn on the cooker, the kitchen lamp goes on... Electronic equipment find itself on say 150V rather than 230V and go nuts. I've set of a fire alarm this way once.

On the other hand: Single phase is a very inefficient way of moving power and it causes problems with load balancing for the power company.

Striking a balance would seem nice, so here goes:

A 3-ph connection of less than 50A per phase shall count as single phase service of 2 x phase rating. For example a 3x50A service counts as one single phase 100A service. At the other extreme, a 3x16A service counts as one 32A single phase service.

In new install. Single phase should be used for up to 63A max. and three-phase from 3 x 32A and up. {Jeering from the Brits: Why not 100A? From the Germanics: Heretic! Single phase is stone age! }

Balancing 3x32A is possible as it allows two continous 16A loads to be run simultanously on one phase. Plus the kettle for a few minutes. 32A is enough even to run a normal sized cooker. On the other hand, 63A is still easy to wire and main breakers, RCD:s etc. easily fit a normal panel (16 mm2 cable).

Now: There is one more point for my system. The copper needed to run a 3x32A cable 3P+PEN is 4x6 mm2 = 24 mm2. 63A P+PEN requires 2x16 mm2 = 32 mm2. The difference in cost is probably outweigth by the more expensive 3-ph panel.

A 100A single phase serious is just silly, IMO, since balancing a 3x50A service won't be a problem. And by then you are using an incredible amount of copper: 2x25 mm2 or 4x10mm2, which probably makes the cost of a 3-ph panel less than the savings on the cable.

Next, I argue that main fuse/breakers shouldn't blow/trip unless in extreme and thus rare cases. Furthermore, I would like to mandate three pole breakers on 3-ph circuits to prevent uncontrolled voltages. These ideas, I think go hand in hand.

Hutch, can I use your bomb shelter?

[This message has been edited by C-H (edited 01-08-2003).]

I assume this is a 230/380V system. What phase to phase loads do you anticipate - stove, water heater ... ?

Wouldn't it be simpler to keep things phase to neutral or are you looking for savings on copper and less voltage drop on these higher power items.

As for the po-co, surely the statistics of large numbers will balance out the demand on all phases without seeking each customer's help.

My workshop would be nicer with domestic 3 phase on hand Shelter's open if you need it!

You make an excellent point C-H. I've come across 3x16A 3-phase in some French houses, and wondered how one would best go about connecting 4 heavy loads. I know of some Brits who have encountered problems with this in their French holiday homes, in many cases because they not only want washers, dryers, etc. but also because they are so attached to their trusty electric kettles!

Certainly specifying 3-phase as a minimum of 3x32A makes the load balancing much easier, although this would still cause problems for the big "instant" showers (I don't think these are so common in Continental Europe, are they?).

With regard to load balancing from the PoCo's perspective, I don't see that having single-phase residential services of up to 100A makes that task any more difficult in most cases. I suppose the only extra work might be to keep records of which houses are fed from which phase.

Although all U.K. distribution in towns and village centers is 4-wire from 3-ph transformers, in the case of rural areas it's not uncommon to see one or two houses standing on their own served by a single-phase xfmr which is fed on a 2-wire spur line (i.e. HV spur is 2 phases from the standard 11kV delta). I imagine that to install a 3-wire line and 3-ph xfmrs in all these places would increase the costs significantly.

Yes, Hutch, I agree: Appliances should be neutral to line. That way they would work on both 3-ph and single ph systems. But, this is not the way it is today.

Paul:
I don't think balancing the transformer isn't a problem, but balancing the phases in a cable suppling a small number of houses could be.

Big instant shower: I know Brits use 40-60A single phase power showers, but then again you still have single glazed windows, whereas we have triple or even quadruple window panes. The Germans use 3x25A or even 3x30A power showers... (The largest size is 27 kW/ 3x40A, IIRC) Apparently, they sometimes don't bother with suppling old flats with hot water. Instead the flat gets one h**l of an electric supply. (Like 3x50A)

Swedes prefer to have things like heating centralized: Stockholm has not only centralized heating from power plants in and around the city, but also centralized airconditioning. Yes, really: There are huge pipes in the ground with coolant!

(Gothenburg runs the airconditioners off the hot water. Sounds crazy, but they have a lot of waste heat in the summer. This heat is turned into cooling by the airconditioners in buildings.)

BTW: Do other cities have street heating? Central part of Stockholm does and it is a blessing in winter.

[This message has been edited by C-H (edited 01-07-2003).]

The largest domestic shower I've seen here is rated 9.6kW (40A). These have become much more common in the last few years. I have one of the older 1970s units (a Heatrae Carousel) on my shower which is rated only 6kW.

Quadruple glazing -- Wow, I'm impressed! I knew that triple glazing was being used in America and Continental Europe now, but it's still not really caught on in a big way here. As I've said before, Britain really is slow in getting away from cold, drafty old houses.

Re the underground heat distribution in Stockholm, do the pipes carry hot water or steam?

I know that many years ago Con-Edison distributed steam along a network of pipes under New York City to provide heating. (It's the steam you sometimes see escaping through grids in the street in old movies.) It always seemed logical to me to use the steam from their generating plants in this way rather than just waste all the heat.

I don't whether ConEd still uses this system. I'm sure one of our New Yorkers will provide the answer.

Paul:

Yes, New York's central steam heat system is still very much in use mostly by huge office towers.

Occasionally when you see street maintenance being performed you will see huge orange and white plastic stacks sitting on the street belching out white steam. And I've even noticed some areas where there are cracks in the steam pipes and the steam fizzes out through crevices in the pavement.

Surreal.

I've never seen an instant shower here. Typical water heating in old flats is a 10l natural gas boiler, or if upgraded to central heating a combo heating/hot water gas boiler. There is central heating with heat from power plants (maybe) but sure from waste burning. I think these lines run on steam. Many public buildings are supplied with this type of heating. The standard electrical suplly for flats, more or less regardless of the size, was for a long time 1x 20A, only people with an electric range had 3x20.
Windows: the standard window here was for a long time the double-sash casement. It simply has an inner and outer sash, most continental europeans will probably know them. They were pretty good, but are now being replaced (at least for new construction, but many maniacs also rip out their old windows) with plastic or wooden thermal casements. So double glazing has a long tradition here. Sngle hung guillotine windows were only used here for bays or screened porches where casements would be in the way when open.

The heat is transported as high pressure water, at a temperature way higher than 100°C. Very common, used also in many towns.

The heat comes from power plants, waste combustion etc. Even nuclear power has been used.

The AC is a new system: It's simply seawater circulated and then dropped back into the sea. (Huge quantities are needed)

Quad glazing is still experimental. Any sizeable window becomes too heavy for the frame. Gas filled triple glazing seems to be favoured. (The Germans build houses without heating and Swedish builders are trying to copy this.)

Gas is rarely used here. Gas cookers are replaced as flats are rewired. (There has been a massive drive to rewire in the past decade)

Replace gas with electric??????
Here the vast majority of cooking and heating in urban/suburban areas is done with gas, rural areas are mostly on electric cooking and wood or oil heating. And friends of gas ranges would rather have their hands chopped of than changing to electric. Furthermore for electric ranges you need 3ph service which is simply more expensive than a 1ph one. And gas is _much_ cheaper than electricity here. Typical equipment in an old flat is the following: gas range (3 burners + oven, usually not older than 30 years, most older ones were thrown out during change from coal to natural gas 1970-78, could not be converted), 5l oversink gas boiler in the kitchen, 10l gas boiler in the bathroom, some gas heaters depending on the size of the appartment. Rehabs usually put a central heating boiler in place of the old 10l bathrrom one and replace the gas heaters, but may leave the 5l boiler in the kitchen if there's a longer distance between kitchen and bathroom (in our case +10m)). Many old flats are still on wood heaters (classmate of mine heats appartment with 2 wood heaters for example)
Some people even put up large propane tanks in rural areas for heating and cooking because they prefer it)

Then there are some areas in urban centers where residents of buildings not served by Town Gas buy cylinders of gas (the small ones) to bring home and hook to their gas stove. This is also more popular in some rural areas.

Not to mention that wood/coal stoves are still manufactured - for COOKING!!! I saw one in a hardware catalog that came in the mail yesterday (costs around US$2.000). Why anyone would buy one of those dinosaurs nowadays is beyond me. Guess it's the same people who still insist on fireplaces in this day and age of modern steam-heat.

I won't even go into those scenarios where people still cook using portable oil stoves or gasoline stoves....indoors

[This message has been edited by SvenNYC (edited 01-07-2003).]

Ragnar:

Yes, gas cookers can be better than their electrical counterparts. Not always, though. Modern ceramic rings are good. The problem with gas is the fire safety and health issue: Fire dept. don't like 'em (guess why). Health authority doesn't like 'em as they increase the number of cases of respiratory related medical conditions among children. Gas boilers aren't used here.

Gas meters are rare: You pay €100 per year for the gas. The exact fee is based on the number of rooms you have. There is talk of doing the same to electricity, as meters and metering is expensive.

Very interesting this thread!

The belgian po co try to give to new houses (old installations is a different story)only 2 phases, since they can balance it much better that way.

So, 'till 63A they give monophase but if somebody specifically wants more then they give 3 Ph+N with a minimum of 3x40A and a maximum of 3x63A.

We also always have 4 pole main breakres (in 3 phase systems, of course) so that we don't have "dancing voltage".

One more thing: 40A we use 6mm2, 63A we use 10mm2.

I think that our system very much resembles your proposal, CH?

Well, every summer I'm at a house in Italy where all the cooking is done with propane cylinders, 2 of them in use, usually 1 or 2 empty ones and some spare ones, all stored in the kitchen. Years ago when there was no power all the lighting was done with kerosene and propane.
I agree that modern electric cookers are quite good, but still gas ranges have some advantages (better heat regulation, faster reaction,..). Top here is gas burners and electric oven. Very expensive. Gas ranges are 300 Euro the cheapest ones, and gas is _waaay_ cheaper than electricity. That's also the reason why electric heating is completely nonsense here.
Most of the gas lines are as old as the houses they're in, not too tight, but by far not leaky enough to give explosions (usually result of tampering with the lines), and not nearly as botched as eletrical lines (1", 3/4" or 1/2" painted steel is the way gas lines are run here, still today, sometimes the joints are welded now, but many plumbers still thread and tighten the joints with hemp fibers.) You can continue using these lines as long as you don't extend or move them. Then you have to have them checked which usually leads to having them replaced. After changing the gas lines also all appliances have to meet newest standards, meaning you'll have to dump all appliances older than ca 15 years (maybe not even that). If anybody smells gas, s/he's told to call 128, Wiengas emergency number. Bad idea! Only thing they do is turn off the main valve, seal it and advise you to call a plumber. You don't need them guys for closing a valve!

The only good electric hob (cooktop) in terms of speed and controlability and efficient use of power is an induction hob. Otherwise I'd use gas.

They're as or even more responsive to control than gas and heat pans (pots) evenly and within seconds. As the surface of the cooker doesn't get hot there's little or no residual heat so once you lower the temp the pan cools. They're ultra safe, you can't burn a pot (usually have a max heat trip out as they can read the actual pot temp as there is no heat source below) and if you remove a pot the unit knows and switches off the power.

They heat woks / unusual shape pans much more evenly as the EM field doesn't require absolute direct contact. it's active a few CM above the hob surface.

Also no energy is wasted on small pots, strange shaped pots as it only heats the metal area of the object placed on top where as a radient hob will heat the whole area of the ring wasting maybe 50% of the power.

the only drawback you need to use good quality stainless steel, copper or cast iron cookware. The tefal stuff is rubbish as it tends to heat in spots. If you've got good pots and pans you can't beat it as a system though.

the power consumption is WAY better than a regular ceramic, ring or solid hob with elements. Most of the power is actually heating the pot as opposed to being wasted heating the air/surface of the cooker.

The only other potential draw back is they're pretty heavily dependent on electronics to produce the high frequency AC EM fields needed to heat the pots. We have a De Detrich hob for 2 years so I can't tell you if they'll last the pace or if they die after a few years.

they also have cooling fans underneeth to cool the electronics (4 ultra silent fans) and the do make a slight ticking noise when switching in and out (like tick tick tick tick)

Overall it's a very nice peice of kitchen ware have had no problems with it whatsoever. Very slim, (touch controls), works like a charm!

Belgian,

Welcome back. Please could you visit here ...

https://www.electrical-contractor.net/ubb/Forum9/HTML/000173.html

.. and let me know how you wire your stoves. Thanks.

Thank you , Hutch. I have replied in that thread. I hope it helps you.

Ah, that means Brussels already has a system similar to my proposal: Should make it easier to get it accepted as the EU standard.

SvenNYC wrote:
Occasionally when you see street maintenance being performed you will see huge orange and white plastic stacks sitting on the street belching out white steam.

I have heard of those stacks being put in to keep the homeless from sleeping on the steam vents in the winter in some cities...