Ohhh. Now that can’t possibly be true… Right.
Also the feed to the house is seriously old, as in from the 1980s and might have 9 or 10 AWG cabling supplying to the house. For 50m (165ft).
Bottleneck or not? I trust the conductor in itself is fine as ever, but should the feed be thicker than the internal audio system feed?
Please answer. I need an answer that pertains to audio performance.
Doubtful you have 9 or 10awg service conductors. I’ve never heard of #9s and #10s (THHN/THWN copper) is only good for 30A. Unless you live in a trailer home, the service conductors are likely a min #2 or #3 copper. You could have aluminum from that era but by the 80s it was becoming pretty rare. I would not consider an electric service from the 80s old by any means. The standards haven’t changed that much since then.
Edit: Overhead wiring can be a little different. Open air cabling from the utility can be smaller. In my market, the point of first connection (demarcation between utility and owner) happens at the weatherhead.
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@amsco15 is right. Is this a service feed straight from a utility pole? Old houses with 30 amp feeds were very common, but most have been upgraded to at least 100 amp services because now we have more modern appliances in our homes that draws more power. When you buy a new house, the insurance companies will not insure your new purchase unless you upgrade the electrical service.
And this wire is installed by the utility company, not you, and they will use their cable only.
The utility company will run a smaller wire because the wire is air cooled in the air. But on long runs they would need a larger size for the voltage drop.
Well, everything here is old.
The lights do dim every time the pump draws water, might be related to something else than the feed though.
It’s inrush current from the pump. Rule of thumb is 6 times full running current for a part of one cycle. My house has a newer (20 years old) 200A service and the lights dim when the condensing unit or my 1/2hp irrigation pump turns on. LED light and their drives make this less of an issue.
Okay then.
I went and looked (reads on the wire), found out the old feed is 9AWG. It needs to go.
It’ll be replaced with 3AWG (25sqmm) aluminum. Shouldn’t need more for a single house, right, not even for my audio system. That it’s aluminum shouldn’t matter with a mains line, as I understand it, only impedance matters.
(Do mains feeds of differing materials and geometries have sound signatures? Please, throw money at it and find out.)
There are numerous negative articles about aluminum wiring. I suggest you poke around with The Google before you choose aluminum.
Aluminum is only 61% as conductive as copper so you need a larger size to carry the same current. It also expands more from heat so the connections has to be extra tight or it can overheat and cause a fire. It also has to be treated with anti -corrosion grease to keep it from oxidizing from the difference in material in the termination. Some counties where I live band the use of aluminum service feeds because of the many problems associated with it. But it is cheaper and can save a little money on long runs.
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A copper feed of equal impedance will be a tad over twice more expensive, but damn, I do want that feed to outlive me.
(It’s actually about 15€/17$ per metre, it’s 4x16sqmm plus a concentric 16sqmm protective earth braid, not cheap for 50 meters but maybe I’ll manage…)
In my opinion, having a copper service feed from the utility to the house will not improve your audio sound over an aluminum feed of similar impedance. Or do you have unlimited money? Instead, I recommend ensuring the electric service panel is modern (meets current codes) and properly sized for the house, that the grounding is carefully done, and that you have a dedicated, somewhat oversized circuit for the stereo. Make sure the utility voltage meets the standard they have to provide. Then, a re-generator, in my experience, can provide major benefits for a fantastic sounding audio system. Of course, good power cables are also worth investing in, if you have the budget.
I believe that here in MI. it is against code to use aluminum wire inside the house and possibly may not be allowed on the outside either.
If not checked once in a while the connections tend to get loose from thermal issues or corrode from humidity. There were a lot of corrosion related fires caused by using aluminum wire a few years after it was introduced to save money. You also have to step up a gage or two in order to use aluminum conductors…
Codes can be all over the place regarding aluminum. For example, Chicago prohibits it. Those codes are based upon very old data (70s during another man made shortage of materials), but what are you gonna do? Modern aluminum conductor is made with alloys that solve all the well known problems like creep, thermal issues and corrosion. I don’t allow it in my spec based upon culture but occasionally allow it as a cost savings measure for feeders. I don’t see an issue with its use this way.
Edit: the Chicagoland electric utility company, ComEd, uses 3/0 aluminum conductor with a braided copper shield for all of its 4kV and 12kV underground conductor.
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Now that’s what I like to hear.
I did dare to suspect that modern wiring in “1st world countries” must be made like this.
That’s why I didn’t yet pester my known electrician (who knows his stuff) with these doubts about aluminum. It’s used all over the place here because it’s over half cheaper even when appropriately thick to match copper impedance.
Any doubts about modern, well-built aluminium feed wire, still? The standards are strict here, you know.
Out of all the things to worry about, I’d put this super low on the list. Aluminum conductor is fine. Just one guy’s, reasonably informed, opinion.
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In the day where lowest bidder receives the job. It never hurts to determine what is the material and where was it sourced. One cannot assume all is modern alloy. Assume = Ass-u-me. Best to confirm where and when sourced.
My mains feed was connected yesterday. It is multi core silver plated with a shield and drain. It is dedicated to the audio only.The electrician, who is very good (his father is a physics professor), says it should be grounded at both ends. It is rated at 27A and is remarkably flexible. My system probably draws 0.5A in use, so massive overkill.
Might I inquire what silver plated mains feed cable costs per metre, and what gauge?
Why the silver plating?
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13awg about $45 per metre. 27A
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