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Circuit Status

I was looking to install dedicated circuits - one each to two, duplex receptacles that are located just behind my components (the components are positioned along a solid shelf that is built onto the wall that the duplexes are located on; the duplexes being right behind the components). To that I checked out the current status of the circuit . . . .

I have identified that these two receptacles are the only objects on a circuit running from a subpanel located below and approximately 15 ft from the receptacles. The cable feeding the receptacles is 14/2 Trendex. The cable feeding the subpanel is 8/3 Trendex; the subpanel located approximately 60 ft from the main panel and point of delivery of service into the residence. I replaced the receptacles a few years back with 8200HICN series Hubble. I don't remember offhand how the receptacles were wired, but the electrician did use plastic wire connectors to feed off separate wires to the first receptacle, extending another set of wires off the connectors to the second receptacle. I wired the same. Plastic receptacle boxes at each. Solid copper ground wire from receptacle to connector.

Not knowing all the answers to this, I leave the actual work of wiring to electricians. But I would like to know just what should be upgraded in this circuit. My guesses with limited knowledge: 12 or 10 ga cable to the receptacles, perhaps better receptacles, optimal placement of receptacle cable at subpanel (although it is positioned with nothing opposite it). Am also wondering if indeed dedicated circuits to each is any better than having both (but just the two receptacles) on a single circuit.

Sounds naive is is somewhat naive. Never thought much about AC supply until recently. Poured through searches and came across quite a bit. But I suspect that to a degree, the existing circuit is close to what should be.

thanks
terra3
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terra3 OP
60 posts
 
Having to bring up this thread again as I'm now at the point of having an electrician come in to install. I live off the beaten path, so choice is limited; more so the experience or knowledge of electricians regarding this type of work. The one I'm going with at least has an appreciation of the idea of dedicated circuits, albeit on a different scale.

He is wondering whether a new, heavier gauge line extending from the main to a 2nd subpanel located in close (5 m) proximity to the audio receptacles would be good. Taking that further, if indeed good, he is thinking that from that subpanel, he would 1) use but upgrade the existing 1 + 1 pigtailed duplex line, and 2) install two new dedicated lines - each to one duplex (I have two existing duplex outlets nearby that would be ideal if they aren't tied into much of a circuit as is).

Advice/opinion? If indeed suitable, what gauge best for the main line to the new subpanel. As well, with this array, is there some obvious grounding issue? Any other particulars?

Many thanks. I understand music and groundwater. Not detailed electricity circuitry setup.
jea48
4,425 posts
 
Main panel is preferential to a sub regardless of the connection between main and sub?
01-19-09: Terra3
No, not necessarily..... But in your case the main panel would be a better place to feed your audio equipment from.

The #8 wire that feeds the sub panel is too small to maintain a good stable non fluctuating voltage for your audio equipment because of the induction motor loads that are connected to it.
By the way doesn't the boiler system also have a circulating pump on it? Another motor load.
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terra3 OP
60 posts
 
The cable is noted as "Trendex" . . "NMD-7"; manufactured by Canada Wire. The main breaker does indeed have a 40A breaker.

Main panel is preferential to a sub regardless of the connection between main and sub?

I'm not all that up on the particulars of this, but 9f indeed a subpanel connection is o.k., is the idea on the subpanel connection to have minimal and/or low current circuits sharing the same bus as the audio circuit? If so, washer/dryer aside, the other circuits (including the boiler - gas boiler with electrical only for 'spark' and temperature sensor) should be relatively low draw? Or is it the total draw on the subpanel? Of note is that my central vac also shares this same bus.

many thanks for suggestions/direction and getting me thinking along . . . . .
jea48
4,425 posts
 
The cable feeding the subpanel is 8/3 Trendex; the subpanel located approximately 60 ft from the main panel and point of delivery of service into the residence
Terra3

What is Trendex? Do you mean Romex?

Are you sure the wire feeding the sub panel is 8/3? #8 awg copper has an ampere rating of 40 amps.

There are other circuits off of the subpanel. The house was built pretty much on one level, but long ranch style, so the subpanel serves the central and west end of the residence. The circuits include lighting, electrical outlets, water boiler (hot water heating), central vac, wash/dryer, fire alarm and jacuzzi. Objects on the same bus (think I have this right?) as the component outlets include lighting, receptacles, washer dryer, fire alarm and the boiler.

That could be a good load on a 40 amp feeder.

Check the main electrical panel for the breaker that feeds the sub-panel. How big is it? The two pole breaker handle will have a number on it. Is it a 40?

At any rate the best way would be to have the electrician install at least 2 new 20 amp dedicated branch circuits all the way back to the main electrical panel if possible.
75 feet is a fair distance and you only want to have the job done once. Play it safe and have him use solid #10 copper wire.

Two 10/2 with ground NM-B cables if possible.
(Romex brand is just one example of NM-B type cable manufactures)
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terra3 OP
60 posts
 
There are other circuits off of the subpanel. The house was built pretty much on one level, but long ranch style, so the subpanel serves the central and west end of the residence. The circuits include lighting, electrical outlets, water boiler (hot water heating), central vac, wash/dryer, fire alarm and jacuzzi. Objects on the same bus (think I have this right?) as the component outlets include lighting, receptacles, washer dryer, fire alarm and the boiler.
zargon's avatar
zargon
453 posts
 
Terra, it appears that your two outlets are daisy chained, and thus you have in effect only 1 dedicated circuit. That circuit is a perfectly valid dedicated one since it comes directly from a subpanel.

You need to determine the total steady state current draw when all your components are on but not playing music, and then the peak draw when the amp is maxed out. You will use this to help determine if more circuits are needed, and if you need to go to 20 amp. Since you runs are relatively short, that may not be necessary.

I would suggest a minimum of two circuits, although some run several just to be conservative. You might be able to keep the one you have and just add another. Are there any other circuits in that subpanel?
sufentanil's avatar
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sufentanil
782 posts
 
Two dedicated circuits are ideal, although you have to keep in mind the possibility of a ground loop issue. You'll need to use at least 12 ga wire if you want to have the capacity for 20A, which is what I would recommend.

Michael
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