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
Yes you can run a 15 amp power conditioner on a 20 amp circuit. You're not suppose to run 20 amp on 15 amp circuits. I'm not sure what you're talking about with future 20 amp options on an amp. Do you mean 240 volt instead of 120 volt? 
If you install a 20-amp breaker, run a #12 or #10 branch circuit and install a Nema 5-20R receptacle, that will cover all 120 volt options for 15 or 20 amps.

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. The twist helps cancel common mode noise. The worst wire to use is 2-wire romex because the hot and neutral are parallel to each other, which makes it a very efficient RF antenna.

gs5556
874 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
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. 
@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


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

The problem is the use of 4 conductors in the cable twisted assembly instead of only 3 conductors. Hot, neutral, and equipment grounding, conductor.

Solution.
Armor Clad for Healthcare Facilities (AC-HCF) Aluminum Armor Clad for Healthcare Facilities (AC-HCF) is the best choice for Isolated Ground A/V systems. Like MC, it contains an additional grounding conductor, although with this type of cable it is permissible to use the metal jacket as the safety grounding conductor, as required with isolated ground installations. The biggest benefit is that the average proximity of the hot conductor and the neutral conductor with respect to the isolated equipment grounding conductor is nearly equal, virtually eliminating ground voltage induction (GVI), even on long runs.

Like MC, it contains an additional grounding conductor, although with this type of cable it is permissible to use the metal jacket as the safety grounding conductor, as required with isolated ground installations.
https://info.legrandav.com/l/71782/2018-12-14/7zh25n


"although with this type of cable it is permissible to use the metal jacket as the safety grounding conductor,"

Yeah, but..... There is a bare armor/bond wire that runs the entire length of the cable. The armor/bond wire is used to ground the outlet box and the supporting back strap of the duplex receptacle. The green insulated conductor, that is part of the twisted Hot and neutral conductor assembly, connects to the IG isolated ground terminal screw of the receptacle outlet. Three conductors twisted together. Hot, neutral, and IG equipment grounding conductor.

  • Interlocking aluminum strip
  • Easy to identify green armor

  • Full size green insulated copper grounding conductor plus armor/bond wire combination provides redundant ground or isolated grounding capability
  • https://www.afcweb.com/ac-hcf-armored-cables/hcf-lite-aluminum-health-care-facilities-cable/

    .
    @masi61 
    I'm sure your electrician knows what 3 wire is. I assume he licensed in your area and knows the local codes. I wouldn't worry about all this banter and reading a bunch on wiring unless you want to tackle it yourself. Let the guy or gal do the job and anything you don't understand I imagine they would be happy to explain. 
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    @jea48 - I’m going to read through the information you provided. I will show it to my electrician. I may have to take notes and write down the names of the types of grounds and the specific cables recommended here in order to get a proper estimate on running a dedicated 20 amp circuit that not only is fully code compliant but also as quiet and with as good of sound quality as possible for my system.
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    Good grief. Half a page basically telling the guy if the electrician is licensed and follows code it's a basic wire job any apprentice could do. Like I said tell the electrician what you want why you want it and leave him or her to it. 
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    I'm just trying to help the OP out. He hired an electrician I suggest he talk to him, tell him his concerns and needs. You don't like my post then flag it.
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    You can think whatever you want but in the end what's  the OP going to do other than trust the electrician. I trusted my plumber to upgrade my bathroom, was that a mistake? I may be ignorant on a lot of things but running a 10/2 wire from breaker to a receptacle isn't one of them. 
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