Hi ,

I wonder if this data is anywhere available, I didn't find any.

I would like to know what the peak current amplitude from a 120V or 240V outlet could be, or the peak output power.

I'm talking about the instantaneous peak power over 2 to 3ms on the peak of the sinewave voltage fed into a very low resistive load.

I know this depends on:
- house wiring (length of wire and it's impedance)
- probably distance from HV transformer on the street
- the circuit breakers magnetic tripping characteristics, but let's ignore these for now.

Thanks for your ideas

 

It pretty well depends upon the power line impedance, so the peak current could be very high before a breaker opens.
How much current are you looking for?
How will you switch it?

 

I think at most 500A , probably 300 to 400 Amps would do it, and I hope to get away with semiconductors for that short amount of time. It would not be used continuously.

Didn't think about the details of how exactly to switch it yet.

It's just I have no idea at all how much we could get out of it.... Maybe need to test it

EDIT: Just saw, the voltage drop due to the pure resistivity of let's say 10m of 12AWG already puts quite a limit to it...

 

- the circuit breakers magnetic tripping characteristics, but let's ignore these for now.

I thought these would be included in what you are looking for?
A 15amp Stab-Loc type service panel breaker does not trip at 15amps, it has an inherent time delay feature it has to take care of inrush loads etc.
You would need to obtain the breaker characteristics from the manufacturer, there are also specialty breakers for unique loads.
Max.

 

I thought these would be included in what you are looking for?
A 15amp Stab-Loc type service panel breaker does not trip at 15amps, it has an inherent time delay feature it has to take care of inrush loads etc.
You would need to obtain the breaker characteristics from the manufacturer, there are also specialty breakers for unique loads.
Max.

Yes I saw those for a small 20A breaker minimum magnetic trip cuurent would be around 9x nominal...

Ok let's say then I go directly from the output of the 200Amp breaker in the electrical panel... there is still the big unknown of input wiring impedance etc...
So it seems that's not information that is available .

 

I think at most 500A , probably 300 to 400 Amps would do it, and I hope to get away with semiconductors for that short amount of time. It would not be used continuously.

Didn't think about the details of how exactly to switch it yet.

Well, switching that amount of current at the mains voltage is far from a trivial task .
And, if it's only 2ms, you will need a phase operated switch to switch at the peak of the waveform voltage.

 

A little quick math shows 0.6788 ohms as the sum of all impedances.
629.8 feet per ohm in 12 gauge wire.
That's 427 feet, round trip, so it's possible. The wire is not going to destroy the idea.

How you gonna do the switching is what's left to design.
Umm...zero crossing detector, wait 4 milliseconds, switch on for 2 milliseconds...something like that.

 

....I wonder if this data is anywhere available, I didn't find any.....
.... would like to know what the peak current amplitude from a 120V or 240V outlet could be, or the peak output power.....instantaneous peak power over 2 to 3ms on the peak of the sinewave voltage fed into,........ circuit breakers magnetic tripping characteristics, but let's ignore these for now.....

So much for ignoring the real substance of the matter.

You should not ignore a few more things:

Go ahead and "tap" your service conductors ahead of your main overcurrent protection device, but be careful to use large enough tap conductors, and the largest (per NFPA70 or equivalent code) parallel overcurrent device allowed. Be certain to size grounding conductors adequately (again, per code) for the protection of the electrical equipment and conductors, as well as the structure you're doing this in. There are very good reasons all this stuff is closely regulated by "fire codes".

10,000 Amps of instantaneous available fault current is so commonplace it'd blow your mind. If you don't already realize that, well, now you should. You SEEM to have a clue about peak available currents, and small time frames, and are quickly finding out about the size/extents of the power circuits you actually tap into. That said, keep a sharp eye out for comparatively low impedance elements of your circuit and elements as well as possible flash over points. 240V RMS obviously has a higher peak voltage for that flash, but still is pretty safe and manageable.

 

Does thos question relate to your avatar?