Why do circuit breakers go up for on and down for off?

Feb 11, 2023 Last reply: 2 years ago 1839 Replies

Steam locos were not rated in horsepower, but 'tractive effort' . How many tons of pull they could generate before the wheels slipped.

That's why they had a lot of driving wheels - at least four, generally 6 and up to 8.

At a given slope even the loco alone cant get up it which is where rack and pinion railways come in.

Mains was always AC post WWII and probably post the advent of consumer tube radios and IIRC was always 240VAC post WWII.

"The Electricity (Supply) Act 1919 merged the 600-odd local generating companies into area boards, who in turn were centralised into the Central Electricity Board by the Electricity Supply Act 1925. That is when the voltage was standardised at 240V, and the National Grid created.

(But DC persisted, in some areas as late as the mid 60s. Refrigerators, Vacuum Cleaners, Sewing Machines, Electric Drills, Radios and TVs were available with universal input. They would all work on AC or DC 240V (one or two DC areas were only 180V, like Dundee or Exeter))"

There were at least two classes of licence - you needed to learn morse for the higher licence that permitted more options and made for long range communications.

27MHz AM radio control had been around for a long time and I don't think a licence was required. 35MHz FM came in later, again no licence required.

Imported CBs were 27MHz AM and caused problems with ambulance service communications IIRC. When CBs were legalised, it was on 27MHz FM, with the AM sets remaining illegal and the FM sets being limited to 4 Watts. Only 40 channels were legal, although some imported sets could access 80.

And then the EU stole ten of our good, English volts!

Have we got them back yet?

That rather contradicts your first para.

You were usually recommended to use each needle only once. Gramophones often had a little caddy to put the used needle into.

Shellac is very hard. Before I could get proper needles for an electric record deck I inherited I use panel pins without any trouble.

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In the early 1960s, Cambridge was supplied with 200v.

In the 1960s it required a license. The advent of CB "good buddy, there's a bear up your rear' types more or less destroyed the band.

RC moved up to 35Mhz and 40Mhz. 27 is now cars and toys only. No licenses were required

They did.

Not really.

When CBs were legalised, it was on 27MHz FM, with

Not sure that is correct. 27 was always AM. I dont think there were more than about 10 channels either

DC and non 240V was highly localised and never part of the National Grid.

The National Grid was for higher voltages. Local boards distributed at 33kV and below.

More shocks doesn't mean more deaths. You jump more at 240V, so are more likely to let go. Try touching a 6000V electric fence and you'll see what I mean.

The ratings in the UK are wrong. If I run the exact rating of a wire, in free air, it will get to just over body temperature. Now put that in the attic with insulation....

No they're started by shorts under the floor or in the walls where you don't notice them. Or a wire that's been damaged by a rat etc and become thinner. It will not get hot at the rating of the breaker. The breaker is no longer preventing a fire. More current - more heat - more fire.

Extension cords in the UK have something called a fuse in the plug. I know, a novel concept for Merkins, we actually have something to stop each individual appliance/extension cord overheating. The cord can be thinner than the circuit the breaker is "protecting", and the fuse will blow if you overload it.

That's stupidity and irrespective of whether you have fuses or breakers.

I still have those in my house and don't intend to change them. They're far less fussy about a surge than a breaker. I switched on 7 computers at once on a 32A circuit, and the breaker tripped. I changed it back to a fuse and it let them boot up. They only use 16A once running. The breaker couldn't handle the inrush current to charge up the bulk capacitors in the power supplies.

And if a breaker does that, you slot in a bigger breaker. How is this anything to do with the advantage of fuses/breakers?

Then you were using the wrong type of breaker.

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I seem to remember something about "son of a gun".

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In about 1980 I lived on Hemphill street in Fort Worth. A lot op people would say it without the middle "h".

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That's just what I was thinking would be a good idea.

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"touch the brake lightly" when you need to do it hard?

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Will you promise to keep the fire from spreading?

No they didn't. The reference simply changed to 230V, so that 220V and

240V countries could use the same, single design of 230V equipment, designed with a wide enough tolerance to cope with the lowest permitted voltage on 220V systems and the highest permitted voltage on 240V systems. The voltage supplied did not change.

I suppose this assumes that the tracks do not bend, vertically or horizontally, or some of the wheels could loose pressure, as there are no springs on the loco wheels (but the wagons do have them, so there must be imperfections on the tracks).

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