What type of wire for dedicated 20A AC lines?

No connected load on the branch circuit and you measured a 5V VD on the end of line.

Yes. The lame ass electrician stripped the wire when pulled. The plaster & painter didn’t cover the boxes and the wire barely made connection is some places.

About 45 years ago my mother-in-law’s house barely escaped a fire when the same sh!tttily done aluminum wiring nearly set the receptacle alight.

Where was your reference point used for the measurement? At the electrical panel?

Where else?

What type of volt meter did you use?

calibrated Fluke.

I’ve been fixing wiring for my HiFi for 50 years. There are all kinds of idiotic claims being made. Few know that plain old Romex beats fancy wiring in a conduit. See Microsoft PowerPoint - Indy AES 2012 Seminar w-Notes v1-0.ppt (wordpress.com) by Bill Whitlock. The paper addresses N O I S E while audiophools prattle on about current which is a non-issue in a properly wired installation. We ran over two kilowatts of amp power on a single 20A breaker. Never blew once. Adding additional loop area is just plain  D U M B !

@poppsg , yes Ohm’s law absolutely comes into play here! I remember those formulas back from school; I really got into that stuff. I’m by no means an expert. I will call you on “It is also true that devices designed to plug into general purpose outlets cannot exceed 15amps.” which isn’t accurate when referring to momentary “peak current” or “instantaneous current” which can go up to 70A for milliseconds at a time. Again, I’m no expert, but I think this is pretty widely understood when it comes to amplifiers!

70A into 8Ω is 39.2KW. Ain't never gonna happen in a power amp.

200W into 8Ω is 5A @ 40V. Even a 3x peak is only going to draw about 5A from the line for a fraction of cycle.

2x200W amp might take from mains close to 1kW during peaks. The problem is that peak supply current won’t be expected 8A, but rather close to 40A. It is because current is drawn only for very short time (millisecond pulse) at the peak of full wave rectified sinewave. It applies to most of LPS. Power delivered with such short pulses not only creates larger voltage drops in house wiring, but also heat-up amp’s power transformer, that has to be oversized (higher copper losses and higher core losses for eddy currents and hysteresis).

 

jea48 said:

Where was your reference point used for the measurement? At the electrical panel?

ieales response:

Where else?

Usually the no load voltage is checked at the last outlet on the branch circuit. No loads are connected to the circuit. If a difference of potential, voltage is present it will be the same as the applied voltage at the feed end. In this case the branch circuit breaker to neutral bar voltage.  If 120V at the panel it will measure 120V at the end of the branch circuit that has no load connected to it. (Add load and then measure again for VD.)

Why? Simple Ohms law. You need a load to have a VD. No load no VD. The internal resistance of a typical DMM is about 10M ohm. 

     jea48 said:

What type of volt meter did you use?

ieales response:

calibrated Fluke.

10M ohm internal resistance. 120V / 10M ohm = 0.000012 amp.

Jim

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