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Using 15 amp power conditioner and power cords with 20 amp wired outlet.

I’m thinking of having my electrician run a 20 amp dedicated line in place of the existing household line that is in the living room of my 1959 built house and most likely is ungrounded and part of a string of multiple outlets on the same circuit. 

I know this has probably been covered many times before and, yes I may check the archives for solutions but thought I would inquire here anyway. 

Since I’m going to he trouble of running a dedicated line, I figure I might as well get it to 20 amp specs. In the future I may order a new solid state amp in the 20 amp version for better bass and dynamics. 

For now though, I would continue to use my existing 15 amp power conditioner (Bryston BIT-15) and power cords. As far as I know the power conditioner would protect my components and nothing would malfunction as far as I can tell. Please feel free to educate me here. 

My future 20 amp upgrades would be a new Bryston cubed series amp with a 20 amp option and possibly moving up to the Bryston BIT-20 power conditioner for better bass, quietness and dynamics potentially with my low impedence Thiel CS-3.6 speakers. 

Thanks for any help.
masi61
oldhvymec
5,101 posts
 

gs5556874 posts

My advice: use romex 10/3. Cut the bare ground and use the insulated red for ground connected to the receptacle ground screw. Be sure to put green tape on the red wire where it is visible. This feeder works the best IMO since all the wires are twisted at the factory.

So don't use the bare ground at all. Use the insulated red one but mark it with green.  I understand all that.

I don't understand "all the wires are twisted at the factory" romex?
Did I miss something.. Isn't Romex flat? If it's flat, and not twisted, why abandon the wire intended for the original ground, why not use both one for ground, and one attached only at one end as a shield. Would that work, and still be code?

Regards
masi61 OP
97 posts
 
I’ll have to look up and see what “10/3“ Romex looks like. Once I find it, I’ll tell my electrician about it and see much it costs & if is available.

@djones51: As far as I know, you can order Bryston power amps with a 20amp power cord. 
djones51
4,947 posts
 
OK, it just means the blades are different on the plug. The two flat blades will be perpendicular instead of parallel. 

https://www.homedepot.com/p/Legrand-20-Amp-125-Volt-Straight-Plug-PS5366XCCV4/100189052
jea48
4,486 posts
 
@masi61

An Overview of Audio System Grounding and Interfacing.
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf
Read page 16.
Read pages 31 thru 36.
Pay close attention to pages 32 thru 35

~ ~ ~ ~


Middle Atlantic Products.
Integrating Electronic Equipment and Power into Rack Enclosures Optimized Power Distribution and Grounding for Audio, Video and Electronic Systems
Metal Clad (MC) is manufactured in both steel and aluminum with twisted conductors that help reduce AC magnetic fields. Although the steel jacket helps reduce AC magnetic fields, the twisting of conductors has the greatest effect on reducing these fields. Another benefit is the constant symmetry of the phase conductors with respect to the grounding conductor which greatly reduces voltage induction on the grounding wire. (NEC article:330)

Two conductor plus 1 ground MC (Metal Clad) is a good choice for Non-Isolated Ground A/V systems. MC cable contains a safety grounding conductor (wire). The three conductors in the MC cable (Line, Neutral and Ground) are uniformly twisted, reducing both induced voltages on the ground wire and radiated AC magnetic fields. The NEC article 250.118 (10)a prohibits the use of this cable for isolated ground circuits because the metal jacket is not considered a grounding conductor, and it is not rated for fault current.


Two Conductor plus 2 ground MC (Metal Clad) may be used in an Isolated Ground installation, because the cable contains two grounding conductors (one for safety ground and one for isolated ground).

The conductors are twisted, but the average proximity of the hot conductor and the neutral conductor with respect to the isolated grounding conductor is not equal. Under load, this will induce a voltage along the length of the isolated ground wire, partially defeating the intent of isolation (see Ground Voltage Induction section of this paper).
https://info.legrandav.com/l/71782/2018-12-14/7zh25n


Solid copper 10/2 with ground MC aluminum armor cable.
https://www.lowes.com/pd/Armorlite-250-ft-10-2-Solid-Aluminum-MC-Cable/3637694


.
oldhvymec
5,101 posts
 
The conductors are twisted, but the average proximity of the hot conductor and the neutral conductor with respect to the isolated grounding conductor is not equal. Under load, this will induce a voltage along the length of the isolated ground wire, partially defeating the intent of isolation (see Ground Voltage Induction section of this paper).

This is not good? Right...? Don't you want isolation?

Regards
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