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Post by 405x5 on Feb 19, 2018 16:30:41 GMT -5
I am looking for a little advice. I am going to install two new dedicated 20A lines for my media room. (Using one line for my amps and using the other for my subs) Code calls for 12AWG wire, but I did not know if I should do 10AWG. The run will be about 75'. The only downside to the 10AWG will be the stiffer wire gets a little harder to fir inside of the service box and fish through the wall a little. Any one have a suggestion on what to do? Nothing in a home theater install would need 10 gauge. I do similar, sub. On a 15 amp. With ALMOST nothing else on board, and my other components on another 15 amp. again with almost no other load, but not “dedicated” lines which are different then regular circuits. All the copper is 14, by the way, and my main amp. Is 400 Watts rms. X5 and the sub. Is 1250 /3000 Watts peak. Bill |
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Post by davidl81 on Feb 19, 2018 17:07:27 GMT -5
I am looking for a little advice. I am going to install two new dedicated 20A lines for my media room. (Using one line for my amps and using the other for my subs) Code calls for 12AWG wire, but I did not know if I should do 10AWG. The run will be about 75'. The only downside to the 10AWG will be the stiffer wire gets a little harder to fir inside of the service box and fish through the wall a little. Any one have a suggestion on what to do? Nothing in a home theater install would need 10 gauge. I do similar, sub. On a 15 amp. With ALMOST nothing else on board, and my other components on another 15 amp. again with almost no other load, but not “dedicated” lines which are different then regular circuits. All the copper is 14, by the way, and my main amp. Is 400 Watts rms. X5 and the sub. Is 1250 /3000 Watts peak. Bill In reality the 20A may be a little overkill for what I need, but I need the new line(s) anyway (current set up has the media room 15A line shared with another room in the home) so it's just as easy to make it a 20A line as it is to make it a 15A line. I plan on running the DR-2 when it arrives and my current XPA-5 on one of the circuits and then run my two SVS PC-12 Plus subs on the other 20A line. I may also run my AVR on the line with the subs. The subs are 800W RMS (1600 RMS total) so with an AVR pulling maybe 300W (only running small in ceiling speakers currently) I am sure I will be fine. |
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Post by 405x5 on Feb 19, 2018 17:34:38 GMT -5
Nothing in a home theater install would need 10 gauge. I do similar, sub. On a 15 amp. With ALMOST nothing else on board, and my other components on another 15 amp. again with almost no other load, but not “dedicated” lines which are different then regular circuits. All the copper is 14, by the way, and my main amp. Is 400 Watts rms. X5 and the sub. Is 1250 /3000 Watts peak. Bill In reality the 20A may be a little overkill for what I need, but I need the new line(s) anyway (current set up has the media room 15A line shared with another room in the home) so it's just as easy to make it a 20A line as it is to make it a 15A line. I plan on running the DR-2 when it arrives and my current XPA-5 on one of the circuits and then run my two SVS PC-12 Plus subs on the other 20A line. I may also run my AVR on the line with the subs. The subs are 800W RMS (1600 RMS total) so with an AVR pulling maybe 300W (only running small in ceiling speakers currently) I am sure I will be fine. That’s great....It was only a suggestion to make things easier by avoiding the unnecessary 10 gauge! Bill |
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Post by Deleted on Feb 19, 2018 19:49:23 GMT -5
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Post by thompson12 on Feb 20, 2018 23:11:15 GMT -5
What (if anything) are you guys using as surge protection / power filters on these 20A lines. Looks like most “surge protectors” have 15A fuses on them, but I’m sure there are some 20A models out there. Of course since it is a dedicated line how important is surge protection anyway?  Mitch |
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Post by jonnyquest on Mar 2, 2018 16:43:32 GMT -5
Why not do four 15A circuits using 12/3 for each, and using the half width breakers to effectively take up the same number of slots in the breaker box?  - that's what I'll probably end up doing. I am not an electrician but I believe what you are proposing is against code. If you are proposing 4 runs of 12/2 (ground is typically not called out) then everything seems ok (assuming your panel is certified for half width breakers). But if you were going to use 2 runs of 12/3 then you would be sharing the neutral between two circuits. This is ok if you are using (2) 2 pole breakers, but you can not use half width breakers because both breakers are on the same leg. When sharing a neutral each hot must be on two different legs which are 180 degrees out of phase from each. Your house has two legs, using one hot leg and a neutral gives 120V using both hots from different legs gives 240V. If you look at the panel every other slot going down is an alternate leg. Hence a double breaker is used for 240V circuits. So when sharing a neutral properly only the out of balance current travels on the neutral wire. For example one hot is pulling 12A the other 7A the neutral would carry 5A. If the same leg was used for each hot and sharing the neutral (against code) the neutral would carry 19A overloading it! |
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ttocs
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I always have a wonderful time, wherever I am, whomever I'm with. (Elwood P Dowd)
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Post by ttocs on Mar 3, 2018 14:00:43 GMT -5
+1 on solarrdadd's very good and detailed post above on Feb 18!
I'm not a licensed electrician, but I do build really big unnecessary homes for a living. Inspectors in my neck of the woods frown on 20A "cheaters" (tandem) breakers but are ok with 15A versions. You might consider swapping a couple of 15A circuits for a 15A tandem so two normal 20A breakers can be used for your system. Thoughts solarrdadd? I be curious.
Or, when considering using the last opening in a panel, I think it's wise to do as thompson12 suggests and install a sub-panel.
I installed four receptacles each with dedicated circuit for my audio and video equipment. Two are isolated ground (main amp on one, two subs on the other), and the other two are shared isolated ground, all with hospital grade receptacles which really have a very good "bite" on the plugs.
edit: oops. forgot one thing. Verify your panel can accept tandem breakers and if so, how many and which positions can be used. My panel can accept 4 of them.
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Post by audiobill on Mar 3, 2018 15:31:53 GMT -5
20 amp lines? I can't fathom it.
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Post by 405x5 on Mar 4, 2018 0:32:45 GMT -5
When I setup my gear, I didn’t run extra anything. No new wiring at all....simply did the math.
All that’s needed is to stay at around 80 percent Max. of the capacity of each circuit used.
After tracing the nearby outlets I came up with two and well under budget on amps. With no new wiring.
Then just plug in without making a big deal out of nothing.
Except for the super high power amplifiers, few other components draw enough amperage to really challenge typical household circuits.
Still, it’s prudent to know what’s on each one and that the grounding is in order.
Bill
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Post by davidl81 on Mar 17, 2018 9:12:40 GMT -5
So I finished running the lines yesterday. I ran 6 total 12awg THHN lines through conduit to the breaker. Each line has one outlet that has two plug on it. So on the wall there are four total plugs, the left two are on one circuit and the right two are on another circuit. I have my amps one one circuit and my subs and AVR on the other line. It is overkill for sure, but I just feel better since the equipment is in its own dedicated line.
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Post by solarrdadd on Apr 15, 2018 11:46:40 GMT -5
So I finished running the lines yesterday. I ran 6 total 12awg THHN lines through conduit to the breaker. Each line has one outlet that has two plug on it. So on the wall there are four total plugs, the left two are on one circuit and the right two are on another circuit. I have my amps one one circuit and my subs and AVR on the other line. It is overkill for sure, but I just feel better since the equipment is in its own dedicated line. I believe what you mean is you have two duplex receptacles each dedicated with a 20a breaker feeding it. if they are in the same device box, a two gang box, that is called a quad. if they are in a single gang box it would be one duplex per box. for those who are not familiar, a duplex receptacle can have two plugs fed from it. that's what you commonly see in your house and most places. I want you to get the nomenclature correct, they are questions on the Journeymen's exam! it's not overkill, what you have done is separate your a/v power from the rest of the receptacle power in your house, so, you know exactly where it comes from and you know exactly what's on it. no other consumption of power will interfere with your a/v power. your a/v power is clean in respect that it's a "home-run" from the panel/breaker to the receptacle. clean grounds and clean neutrals too. you should have all the power you would need and feel secure that the blender, mixer, coffee maker, that damn dimmer or that cursed vacuum cleaner won't interfere with the quality of the power your getting to your a/v gear. also with everything properly terminated, you should not have grounding issues that non-grounded or improperly grounded receptacles suffer from. sounds like you did a good job David, based on your posts, it's Uncle Solarrdadd Approved!  |
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Post by solarrdadd on Apr 15, 2018 12:48:04 GMT -5
These are NOT dedicated lines, rather separate circuits, which is fine. True, dedicated lines are wired differently including a dedicated line receptical, often used with computers and hospital equipment. Not a bad move for modern HT gear where the processor has much in common with a pc. Bill but, they are dedicated lines, each 20a duplex receptacle has it's own hot, neutral and ground conductor, not shared that go straight back to the panel connected to a single 20a breaker. it doesn't get more dedicated than that. since you used the terms "computers and hospitals" don't get them confused with say "isolated ground/ig" wiring found in certain locations in hospitals and sometimes in computer/server rooms. in this case, the term "dedicated" means to serve one device/load fed by one breaker, which in this case, the device is the receptacle that load is his a/v gear. also, there is no such thing listed (UL) as a "dedicated line receptacle". there are "single" 20a receptacles which are round and can accept only one plugged device (not counting surge/plug strips) and there are "duplex" 20a receptacles which are somewhat rectangular and can accept two plugged devices (not counting surge/plug strips). then of course many odd NEMA configurations, but, these would be the most common types of receptacles. perhaps, somehow, I am not understanding what you are saying bill. are you possibly referring to "locking" type receptacles? those can be in the 120v/20a type and to engage require a NEMA L5-20P plug that "twists" when inserted to lock into place to keep them from easily being unplugged or falling out when properly engaged. that is another type of receptacle. |
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Post by mikoz on Feb 1, 2019 11:37:20 GMT -5
I think the need for this much amperage is really often not needed. I have 2 JL audio fathom subs (F113, F212), a sunfire TGA-7401 plus the usual source stuff, plus 2 monster power (hey, they work well) centers, and even with a single 15A breaker I have yet to come close to hitting 15A. The reason is that most of the crazy loud is momentary and the capacitance of the various amps takes care of that, and most media is such that not all speakers are driving at such high volumes at the same time. I guess there could be esxceptions, e.g. if you're an "all stereo" type of mode, but generally this
Some of these class A-type and some A-B amps that are sitting there wasting power or the amps that truly provide the same power to all channels driven at once... that may be a different story.
I debated about adding a dedicated 20A breaker (plus the existing 15A one in the room) but so far I haven't seen a need. I pull about 4A watching TV/Roku and maybe 10A during a very loud movie, but that's only momentary.
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Post by davidl81 on Feb 1, 2019 12:03:59 GMT -5
I think the need for this much amperage is really often not needed. I have 2 JL audio fathom subs (F113, F212), a sunfire TGA-7401 plus the usual source stuff, plus 2 monster power (hey, they work well) centers, and even with a single 15A breaker I have yet to come close to hitting 15A. The reason is that most of the crazy loud is momentary and the capacitance of the various amps takes care of that, and most media is such that not all speakers are driving at such high volumes at the same time. I guess there could be esxceptions, e.g. if you're an "all stereo" type of mode, but generally this Some of these class A-type and some A-B amps that are sitting there wasting power or the amps that truly provide the same power to all channels driven at once... that may be a different story. I debated about adding a dedicated 20A breaker (plus the existing 15A one in the room) but so far I haven't seen a need. I pull about 4A watching TV/Roku and maybe 10A during a very loud movie, but that's only momentary. I for sure did not need the dual 20A lines. This started out as a project to add one dedicated line to my theater room since the current 15A line was shared with other rooms in the home. I most likely could have gotten away just using that one line, but I wanted isolation for the DR-2 amp I was buying. Since I decided to run the new line it was just as easy to do a 20A line as it was to run a 15A line. Then I just decided to run dual 20A lines since really my only extra cost was one more breaker and the extra wire. My DR-2 amp and my XPA-5 run on one of the 20A lines with maybe the AV8802A as well, I have it connected to a Panamax power center (only 15A breaker on it) that has the amp draw displayed on the unit. I think the most draw I have seen on it is 8 amps on some really loud 2 channel music, and that is only for a second or two. |
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Post by mikoz on Feb 1, 2019 12:10:46 GMT -5
Yeah I understand that, makes sense. In my case, the 15A line is just for that room. My point is that people often think they need tons of power, but in the real world with real media and real amplifiers, the reality is usually much different in most cases. I see some of these 7-ch amps that require 2X20A lines... that's just nuts unless you've got a room the size of an average first floor.
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- that's what I'll probably end up doing.
