Measuring load on a circuit breaker.

[Chris Friesen]

How do you figure that? Power is a scalar quantity given by I^2*R.

Power dissipated by a load is always positive no matter which direction the current flows through the load.

Chris

[Jeff Wisnia]

Yes Steve, I have a couple of GFCI breakers in my home's panel which have the white wire feeding the circuits they protect hooked to them, onto the screw terminal on each breaker marked "Load Neutral".

And, there's also a white "pigtail" wire coming out of each breaker which connects to the panel's neutral bus.

Jeff (Doing the "Told ya so dance" stolen from "Will and Grace" episode

4.09.)

[Mark Lloyd]

Basically what I said.

Considering that there's a "source" of the power and a "load" where it's dissipated. it would be hard not to see a direction in there.

[Chris Friesen]

Technically you don't have a "power source" in an electrical circuit. You either have a voltage source or a current source or a combination of the two.

Power doesn't flow in a circuit--only current does. Power is dissipated by the various components in a circuit. The instantaneous power dissipated by any particular component can be given by I^2*R, where I is the instantaneous current flowing through the component and R is the resistance of the component. (This is all assuming a purely resistive load.)

The electrical utility applies an alternating voltage to the conductors attached to the house. This causes an alternating current to flow in those conductors, with the amount of current depending on the resistance of the various circuits in the house.

Thus, whether you say the hot wire "goes to", or is "connected to", or "comes from" the breaker, it is all equivalent.

Chris

[Mark Lloyd]

Right. Still a source.

No matter what, there is still a logical direction. Note that this direction does seem to correspond to what direction the bill comes in.

[Terry]

I am slow. There is no power source in an electrical circuit? Why do they call it the power company? Ours is called Georgia Power.

Isn't a combination of voltage and current "power" by definition?

[Tony Hwang]

This is quite improper statement. From basic Ohm's law, current/voltage produces power measured in Watts usually which can be converted into Joule, Calorie, Horse Power, etc. Current flows, power does not. There is phantom power(false power, wasted power) in inductive cicuit. Many loads are not pure resistive. There is always inductive/capacitive component.

[Tony Hwang]

They don't send power to you. They send electrons to you which will produce power, LOL!

[Doug Miller]

Really? Always? What's the inductive or capacitative component in a light bulb?

[Steve Barker]

Ours is called Kansas City Power and Light. Which am I receiving?

[Terry]

I know they only send electrons, and they get them back. Why am I being charged for them?

[Tony Hwang]

Hi, Filament has an amount of inductance/capacitance. it is very fine coil. Even piece of wire has finite capacitance and inductnace. Why do you think there is a surge current when light bulb is turn on? Ever heard of phase compensating capacitor or lump inductor. Or go inside a power room in any big commercial building, what do you see there? Do you know why electric cable is some times criss crossed or twisted? Simply to answer your question, Yes, really, always. It becomes very critical on high frequency. Todays florescent bulbs are driven by 44KHz current. Pure resistive circuit in real world is problably near none. Z^2 is combination of R and j(Xl-Xc). Remember HS physics class? Xl and Xc cancels each other, equal value, whatever left is either Xl, or Xc. In real world most load is inductive. In inductive circuit voltage is leading and current is lagging. This phase difference produces wasted power which does not do any work. Ideally the phase difference should be zero. That is why KVA is not equal to Watt rating of a device.(efficiency) I spent my working life on RF telecommunication(mobile and fixed base), UPS, MG, Antenna farm, stuff like that.

[Mark Lloyd]

It's an ENERGY source. That has no effect on the validity of the concept of "source", and the direction (as mentioned with a circuit breaker).

[Sam E]

Why are you being charged for water, when they get most of that back (city sewer)?

[Harry]

The bill. All that paper and ink cost something :-)

[Mark Lloyd]

Yes.

BTW, it was in dealing with that, that I learned about complex numbers.

None of this changes the logical direction here.

[Steve Barker]

I hear ya. and we don't even use that anymore. Pay online and no bill is sent. LOL

[Stormin Mormon]

Well, after many years of working with clamp on ammeters, I guess I'll have to give them all way, and get out of the trade. Cause I sure don't remember a white wire ever coming out of a breaker. With rare exceptions, they have all been black wires out of the breakers. Learn something new every day.

[Stormin Mormon]

Cause they are pushy (double meaning).

E = IR; Electrons = In, Returned.

[Stormin Mormon]

So many things to respond to. I'll have to reply inline.