Audio Precision System One Dual Domani Measuirement Systems

I have one horrible memory of once being at a girlfriend's house in New York (no, that wasn't the horrible bit). She was drying her hair. The drier plug was hanging half out as they always do (bugger all retention or location in a US mains plug) and it was almost glowing red hot from the current.

d

Here's something more representative:-

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*Atheism is a non-prophet organization.

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Googling shows pictures that are nearly identical if not exactly identical.

Not commonly, but occasionally in older dwellings. Most of what you are talking about is due to motor starting surges, so the light dimming is pretty much cosmetic. Not that I would intentionally tolerate it.

Given that our toaster ovens use up about 95% of a 15 amp circuit, two of them put a quick end to 15a fuses and pretty quickly open 15a breakers. The larger microwaves are only a little lighter on the draw, so a microwave and a toaster oven on the same circuit won't be very relaible, either. Ditto for our larger electric coffee and tea pots. I don't know how to get around that.

That checks out.

If my tables are right, 2.5 mm is about 10 gauge, which is a lot more copper than our 12 gauge. Almost twice as much. We consider 10 gauge to be suitable for 30 amp wiring, which would indeed handle two devices from the list microwaves, toasters, coffee pots, etc. A garbage disposal could run on the same circuit without tripping or frying anything. Probably no light dimming, either. And, that is at 120 volts!

250 feet of 10/3 romex runs about $200. I wonder why people aren't importing wire from the UK - your prices are pretty cheap! .

Does not seem to be true. My wire tables say 2.5 mm diameter copper is more like 10 gauge.

It is called 2.5mm, but it is actually 2.5 square mm, which is about your 12 gauge.

d

That makes sense if your rings are 10 gauge (2.5 mm),

There are two cables in parallel since its a ring.

The current is cut in half by the doubled line voltage.

My downstairs has something like ten 120 volt circuits, and there are about another 8 circuits upstairs. As I mentioned, a typical modern US kitchen has

5-6 120 v circuits all by itself, not including the 230 v electric oven.

Electric stoves and ovens are always on their own 230 volt circuit, usually fused for 30 amps with 10 gauge cable. Don't happen to have one - we cook and heat with natural gas.

The 10 gauge wire, the ring configuration, and the doubled line voltage explain all that.

I see the ring as being a bit of a problem. I guess you circumvent that problem by fusing individual power cables on each appliance, if I'm following your discussion.

Does Lake St Clair normally freeze over?

I would guess that this year it has not.

No TV antenna it would appear. Have you never been tempted to put up a tower?

Do you watch CBET or TV Ontario very often?

I notice that you are at the back of a mini strip mall on Mack Avenue in which there are two vacancies.

Have these now been filled or have more stores gone under since the Google car passed by?

Presumably you mean the area around Henry Ford Medical Center Pierson Clinic.

It is surprising how many of the newer building look quite similar to new buildings that one would see in new retails developments in outer suburbs of some European cities.

Ah, is the limit on a 110V circuit only 15A? I can see how you'd hit that limit pretty quickly. I'd assumed that with half the voltage the circuits would be rated for twice the current so as to still be able to drive equipment of the same power.

I suppose a 3 kW (3-bar) electric fire needs more than a normal circuit, given that it draws 12.5 A at 240 V, so an equivalent one for 110V would be a little over 25 A. And as for a 6 kW electric shower, that would be 50 A. Quite a current! OK, so showers need their own circuit even in 240 V land!

As a matter of interest, when a mains socket is switched from a wall switch for use with table lamps so they can all be switched on as you come into a room, are those circuits rated at the same current as other non-switched circuits or are they specially labelled to prevent people accidentally plugging powerful appliances into what is effectively a lighting circuit?

Well you still have the doubled advantage of feeding the ring from both ends and using twice the voltage.

I'm not so sure about rings, but the doubled voltage looks good to me given that I would have enough appliances that ran on 240 volts to be interesting. I don't.

I have a 1500 watt electric pot that heats 1.7 L of water in about 3 minutes. Less water, down to about a liter (what it takes to cover the coils) heats significantly quicker.

Works for me!

Agreed.

On the pole:

Two cable system local feeds plus the main lines for about a dozen streets. Yup, two completely independent digital TVcable/internet/phone systems - isn't competition lovely?

Analog Telephone lines for my house plus the 8 or so businesses

Large analog telephone cable for a goodly number of streets.

Electric 120/240 for my house plus the businesses.

The top 3 wires are 4800 volts 3 phase to keep the power transformers in our back yards happy.

The pole also holds the battery box for one of the 2 cable systems. The other one is in my back yard.

Since the picture was taken, the battery box was about doubled in size and the wiring was cleaned up.

In a newer suburbs it would all be buried.

Yes, but not so much lately.

Correct.

There used to be one, but we've had cable for decades.

No, but I watch the BBC USA channel on cable.

Mack Avenue is solid businesses on the west side from Moross to Vernier, and intermittant businesses on the east side.

I think we have 2 current vacancies. At least 3 new businesses have moved in over the past year, and two that were active when the picture was taken have folded or moved.

There is a major problem with parking. We walk or ride our bikes a lot, but almost nobody else does.

Yes. We call that area "Villiage on the Hill".

BTW the building accorss the street at 120-130 Kercheval is owned by a friend and was built about 5 years ago.

Completely intentional. Strongly encouraged by the town councils.

Many of the residences around here are also in a style we call "Colonial". They sort of go with the stores.

BTW my son lives in eastern Pennsylvania so I know what *real* colonial looks like and this isn't it. ;-)

When these places were wired (1910-1935), underground wiring was prohibitively expensive. Underground became the rule in the 70's.

I'm on my second one, but the first went quietly.

One went off like the 4th of July a few streets over, maybe 10 years ago.

If everything is on a ring, why are there an odd number of breakers?

The ring returns to the same breaker. There isn't a separate one for each end of the ring.

d

True for common circuits wired with 14 gauge wire.

20 gauge wiring is protected for 20 amps.

No.

We simply don't have those. Our room heaters are usually are rated at about

15 amps max.

We don't have electric showers. If electric is used for water heating it is used via a central electric water heater on 240 v. Natural gas rules for heating around here. The economics are far better.

We've had copious amounts natural gas around here from the southwest US and gulf area since right after WW2. Prior to that there was coal gas in lesser amounts and more expensive.

The socket, wiring and switch would usually be rated at 15 amps or sometimes

20 amps.

The breakers are 4 pole?

No, the breakers are normally only single pole, breaking the live only with the neutral and earth (ground) being permanently connected to a bus bar. Both ends of the ring come to the same point on the breaker.

There's a diagram and explanation of how these circuits work here:-

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Tciao for Now!

John.