Which Residential Voltage & Frequency Arrangement Is Best?

You can, but not for use on 32A ring circuits using BS1636 13A fused plugs. The BS4343 unfused plugs (for various voltages and currents) are for use on application-specific circuits. Connecting such a socket to a

32A ring circuit would present an unacceptably high point load on the ring, upset the principle of diversity, and possibly mean that an appliance was insufficiently protected by the circuit MCB.

Owain

Reply to
Owain
Loading thread data ...

How many AC motors do you have at home? Mine are almost all (barring my big woodworking machines) universal motors. Even the old shaded-pole motors in clocks and timers have gone digital now.

It's still a terrible idea though. Switching tens of DC amps isn't that easy.

Reply to
Andy Dingley

Keeps the current low, which simplifies simple DC switchgear.

If you really want to run kW domestic appliances from 48V DC, you'd be looking at solid state switches instead of cheap mechanical ones.

Reply to
Andy Dingley

Avionics is very safety conscious, so it tends to evolve rather than innovate. 115V 3-phase alternators are already in service, so the only significant mod is just a rectifier stack.

Reply to
Tony Williams

Yes, although it's not simply a matter of tripping the breaker, but tripping it within the required time (0.4 seconds for circuits with socket outlets, 5 seconds for other circuits).

No. Whole house RCD is not permitted (except >=100mA as described above, and only when really required). I described which circuits are required to be RCD protected (at

Reply to
Andrew Gabriel

The 800Hz hum from a transformer core or motor sounds real nice, too. Not.

Either 50 or 60 Hz is fine. But I'd like to see 480V 3ph in a house. 3 phase, of whatever voltage or frequency will do more for motor efficiency than the other factors.

Reply to
Paul Hovnanian P.E.

Sometimes I forget that normal people have no need for the types of motors I'm used to. Since I'm mainly concentrating on industrial construction right now, my mind kind of kept going with everything I'm familiar with.

Reply to
sanjian

Truth is that lots of kit still uses transformers.

Also I thought the question was what would one do starting around year

1900, and 48vdc would have been a difficult voltage for much of the century.

Andy Dingley:

Last time I switched >100A dc I used 2 copper washers. The extra complications over ac are not major, as long as its low v.

NT

Reply to
meow2222

I read up on this in detail a while back, might have started from the wiki ACFI page. In brief, higher v means both lower run current and higher fault current, producing very much better fault discrimination and fault clearance. There is also the lesser point that some faults dissipate less heat on higher v.

NT

Reply to
meow2222

It's a rhetorical question anyway. There is no place on the planet that does not already have electric service in some form or another, so anything you would impose would need to match waht is already there. You cannot "start from scratch" any more. No matter what you do, you will have problems and benefits based upon what is already in existance. A better approach is to look at your most important likely trading partner. If that is going to be the US, i.e. you are going to be importing machinery and appliances from US suppliers and your populace is going to travel back and forth a lot, use 120/240 60Hz. If not, use 220 50Hz. All other arguments are pointless.

Reply to
Bob Ferapples

The message from Bob Ferapples contains these words:

Really?

Reply to
Guy King

In article , Andy Dingley writes

So they have 270 odd volt lamps then?.

And the Avionics and instrumentation all 270 or is there a lot of step down switch mode?...

I don't think anyone would.....

Reply to
tony sayer

Not sure they are actually.

Anyway, you can make a three phase inverter for AC motors to run on DC fairly cheaply.

My real point was that with the advances in semiconductors, making AC from DC and voltage transformation is not really a huge issue as it was in the 20's when all the grid went in.

Reply to
The Natural Philosopher

I don't think it is either a mistake, or not still carrying on.

Al does not corrode markedly in air except near the coast.

>
Reply to
The Natural Philosopher

Yeah but they switch at a few Khz anyway, so what you feed them from is irrelevant.

They all transform to DC at some point first...

Reply to
The Natural Philosopher

On Mon, 20 Mar 2006 10:41:10 +0000 someone who may be The Natural Philosopher wrote this:-

They are standard equipment.

Reply to
David Hansen

And how dangerous would that be in the wrong hands ?

Reply to
raden

We usually find other, more exiting, uses for the bedroom.

Reply to
Spokesman

Why? What advantage?

400Hz is useful for aircraft because of weight/volume/power considerations but these don't apply. Also 400Hz in home would require frequency converters (extra $$$) as distribution is not particularly practical at this frequency in comparison to 60Hz or below. As for 100V, again why? What gain is made?

The proper answer to the original question is "it depends"

Reply to
Don Kelly

Agreed-partially. While 400Hz requires less iron in a motor, the problem is that, for the speeds of typical household motors, we are looking at much higher synchronous speeds- many more poles. Possibly a large diameter pancake or simply use "brushless DC". Same control problem with that as with a 60Hz supply. Transmission at 400Hz has its problems anywhere where distances are large or L and C are appreciable. so that at local substations there would have to be frequency converter stations- not cheap. May as well go half-way and go DC for less$$.

Now, 480V, 3 phase, sounds good at either 50 or 60Hz.

-- C'mon now, APL isn't that bad to read unless you want to show off with recursive one-liners! At least one can concentrate on the problem rather than the code.

Reply to
Don Kelly

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.