What is everyone using for dedicated AC lines???

Albert: I think that Glen's been playing "sniper in the weeds" with us. Like you, i'm glad that he decided to give Audiogon another shot : ) Sean
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Highend64: I think that you are correct. Due to the air gaps located between the stranded conductors, solid cabling of the same gauge offers slightly more material to pass power through than an equivalent stranded version. I could be wrong here, but that's what i remember. Sean
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Glen: Thanks for posting what you did. I had always thought that 10 gauge in conduit was rated for a max of 30 amps. Given that most of these ratings are running "on the edge" or even "slightly over the edge", i've always found that going at least one gauge heavier than what they recommend helps maintain steady current flow with minimal voltage sag. That's why i said that 8 gauge was good for 30 and "maybe" 35 amps. Sean
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I don't know what handbook you are reading, but try passing 50 amps through ANY 10 gauge wire for an extended period of time and see how hot it gets. Ratings like that are foolish at best. 50 amps of current through 8 gauge will show a very definite temperature rise. As far as i'm concerned, 8 gauge is sufficient for 30 to maybe 35 amps of current. It will obviously pass a LOT more than that on short term demand, but it is at the times of high demand that you want the least sag possible. That may not agree with anything else you ever read, but then again, i'm not willing to accept the low standards that the industry uses. Sean
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If you can find heavy gauge ( at least 12 with 10 being preferred ) twisted pair, that would be excellent. I know that Anixter used to stock 12 gauge solid core twisted pair. This design will lower inductance, especially if you've got a long run. It is bulkier and harder to pull through conduit, but it should offer some benefits.

While i don't know how "lawful" this is in various States, you might want to run this by your electrician. You can use the conduit as ground and isolate it at the breaker box. Install a dedicated ground rod for the audio system in very close proximity to the ground rod that is used the mains and ground the conduit to the secondary ( audio ) ground rod. The two ground rods should be tied together electrically and weatherproofed once you have very solid connections.

Since the rods are tied together at the point of Earth ground, noise from the rest of the house will be shunted at that point. This is especially true since you now have two ground rods, giving you twice the conductive area to ground. Since electricity typically prefers to take the shortest, lowest resistance path to ground, any type of noise coming from the house / AC mains would be shunted at the point of connection.

The system now has a dedicated ground AND is connected to the rest of the house in a manner that should be both legal ( building code & home-owners insurance ) and harmless in terms sharing a common ground. On top of that, your AC feedline to the audio system is basically a 100% shielded low inductance twinaxial cable. This saves you from having to run the third wire and leaves more room to pull the twisted pairs through. Sean
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Garfish ( and others using similar set-up's ): Even if you have four 20 amp breakers, you do realize that these are being fed by a single 30 amp breaker. As such, you are limiting the total current capacity of the sub-box to 30 amps total, regardless of how many breakers and their ratings in the secondary box.

From my line of thinking, you should have had the electrician tie the secondary breaker box into the mains. This would bypass the 30 amp breaker and allow you to pull as much as you needed from the mains. The only limitation at that point would be the master breaker on the smaller secondary box. In order to do this though, you would need to replace the 10 gauge wiring that goes from the AC mains to the secondary box with something heavier.

In my opinion, 8 gauge is sufficient to handle 30 amps continuously, so you would need at least 4 gauge for an 80 or possibly 100 amp service. That is, if you were ever going to pull that much power on a steady-state basis. The reason that they can get away with using smaller gauged wires in most installations is due to the fact that most people aren't pulling that hard on all of the circuits at the same time, so momentary overloads are not that big of a deal.

Please bare in mind that i am NOT a certified electrician and building / electrical code may vary from location to location. As such, the info that i or anyone else posts to a thread like this should always be verified at the local level prior to taking it for "gospel" and acting upon it.

As i've mentioned before, PLEASE correct me if i suggest something wrong, as this is NOT just a matter of opinion on stuff like this. It can be a matter of life, death and /or personal property loss. None of these are matters where mistakes should be allowed to slide as far as i'm concerned and those that are knowledgable and / or skilled professionals should chime in ASAP in such cases. I would much rather have a boot to the head than be responsible for possibly helping someone to kill themselves or harm their gear. If you don't know what you are doing with electricity and wiring, DON'T try this stuff on your own. Sean
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PS... Unlike 9 volt batteries, you should never put AC wiring into your mouth and touch it to your tongue to see if it is live : )

Glen: If you don't mind me asking, what is the second 200 amp sub-panel for ? If i read this right, you'll have a 200 amp main feeding a 200 amp sub-panel feeding a 100 amp sub-panel. The 200 amp main would appear to be for the whole house and you mention using the 100 amp sub-panel at / near your audio system. Where does the second 200 amp panel come into play in all of this ? Sean
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Solid conductors are prefered in any given situation except for situations where flexibility or repeated stress is of concern. I know of "honest" cable manufacturers that will agree with this statement even though most of their products are of stranded design for reasons of flexibility. Twisting reduces inductance and increases capacitance, which helps lower the noise floor and increase the rejection of RFI. Combining the two offers the most benefits with the least drawbacks of any other approach.

As a side note, use the heaviest gauge wires that you can use within reason. 12 gauge should be considered a minimum for any type of A/V installation. Sean
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Glen: You haven't been looking too well then. While Albert shows up from time to time in threads, i know that he's doing more reading than posting. As for me, i never shut up. Then again, you probably already knew that : ) Sean
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