15 or 20 amp?

jayman_1975

I am asking this question for my bro inlaw who is finishing his basement in the very new future. He is planning on running two sets of wires from seperate brakers so he can have his amps plugged in on their own dedicated line.

He has six Marantz monoblock amps. The smaller of the two offerings. MA500 I believe. Is a 15 amp breaker enough to handle these six monos or should he install a 20 amp instead?

Keeping in mind that he is not interested in buying a high end power coditioner/distribution bar and wont be purchasing any aftermarket power cables. Would it then be a waste to go with a 20amp breaker?

samnor

i have the ma500 and Its 180w into 4ohms (125 @ 8) so unless you're bro in law constantly listens at ear shattering levels, one 15amp breaker should be more than sufficient. In theory, he should be getting more than 1600w from the breaker 110V*15a which is well over what you need for 6 ma 500's.

Polkie2009

+1 on what Lasareath said, do the upgrade now while he's in this phase of construction on the basement. He'll be happy to have two 20 amp dedicated circuits, that's something most of us wish we had for our systems,lol.

thuffman03

He should run 20 amp service IMO.

heiney9

15A will handle those amps no problem, but no hurt in going 20A since he's doing it from scratch.

H9

ben62670

An extra 20-30 bucks to go with 20amp. Come on now why even bother with running stuff near max?

zingo

Lasareath wrote: »

If he's running two new lines anywayz then he might as well just make them 20 amps for future expansion. The hardest part Is doing the work. Spending a little more for 20amp breakers, receptacles and wire is much easier.

Exactly.

jayman_1975

Thanks for all the replies. I told him you guys would say to run the 20amp. Does a 20 amp receptacle take a different plug than a 15 amp? If so... he would not be game for having to change up his power cords.

angelsfann02

No. The plug is the same as 15 amp. The 20 amp receptacle does look different. A 20 amp receptacle has a slot going horizontally across both left side plugs.

On3s&Z3r0s

Use 15amp receptacles regardless of whether you go with 20amp or 15amp breakers. I'm sure he already has 15amp receptacles on some of the 20amp circuits in his house. This is totally kosher according to code. It's only bad if you put a 20amp receptacle on a 15amp circuit. Only thing he'll need to do different other than putting 20amp breakers in the panel is to make sure he's running 12 gauge instead of 14 gauge wire. Also, it's a good idea to lay out the circuits so that there are no lights or motors (like a beer fridge compressor) on the circuit that will be used for the amps. And finally, I'd check the codes in your area and determine if his municipality has already adopted the 2008 NEC, especially if he is getting an inspection. That version of the NEC requires AFCI breakers on all circuits serving living areas (not just bedrooms) so he'll need a different kind of breaker to comply with the code in that case. He would probably also need tamper proof outlets, which suck. Well, Cooper TPOs suck, Leviton TPOs suck a lot less.

disneyjoe7

jayman_1975 wrote: »

Thanks for all the replies. I told him you guys would say to run the 20amp. Does a 20 amp receptacle take a different plug than a 15 amp? If so... he would not be game for having to change up his power cords.

A 20 amp receptacle will take both a 15 amp or 20 amp plug.

jcandy

On3s&Z3r0s wrote: »

Use 15amp receptacles regardless of whether you go with 20amp or 15amp breakers. I'm sure he already has 15amp receptacles on some of the 20amp circuits in his house. This is totally kosher according to code. It's only bad if you put a 20amp receptacle on a 15amp circuit. Only thing he'll need to do different other than putting 20amp breakers in the panel is to make sure he's running 12 gauge instead of 14 gauge wire. Also, it's a good idea to lay out the circuits so that there are no lights or motors (like a beer fridge compressor) on the circuit that will be used for the amps. And finally, I'd check the codes in your area and determine if his municipality has already adopted the 2008 NEC, especially if he is getting an inspection. That version of the NEC requires AFCI breakers on all circuits serving living areas (not just bedrooms) so he'll need a different kind of breaker to comply with the code in that case. He would probably also need tamper proof outlets, which suck. Well, Cooper TPOs suck, Leviton TPOs suck a lot less.

15A receptacles can be used on a 20A circuit in the USA but not in Canada. As you point out, people probably do have this mismatch happening in their own homes. Electrical contractors do this in the USA because the 15A receptacles are significantly cheaper than 20A ones. Personally, I would do the "right thing" and match receptacles to the circuit capacity.

F1nut

He would probably also need tamper proof outlets

WTH is a tamper proof outlet?

kawizx9r

F1nut wrote: »

WTH is a tamper proof outlet?

I didn't know either!

Just looked them up, and well it reminds me of that iPhone thread posted days back. The cover plate utilizes special screws to prevent anyone from opening it up (unless you've got a special screw driver for it).

I'm curious, what states require such outlets?

F1nut

Ugh! I wonder what BOZO dreamed up that one.

ben62670

For a while the plugs were installed "upside down" because the ground would be on top in case something got between the plug and the outlet. It would hit the ground first.

On3s&Z3r0s

kawizx9r wrote: »

The cover plate utilizes special screws to prevent anyone from opening it up (unless you've got a special screw driver for it).

I'm curious, what states require such outlets?

That's not true of the tamper-proof outlets I had to install. They were installed with the same sort of flat-head/phillips machine screws as any normal outlet (the screws used to install the outlet are covered by the cover plate anyway, which also installs with a flat-head machine screw. What makes them tamper-proof is that they have little plastic shutters built into the hot and neutral slots. The shutters only open if pressed simultaneously with a 2-prong or 3-prong plug. It theoretically prevents kids from jamming a paper clip in one side or the other and shocking themselves. The batch of Cooper outlets I got were terrible. It would take 30-seconds to jimmy a plug in under the best conditions, and reaching around behind an HT console... forget it. The Levitons are much better if you have to install them.

Incidentally, since 20A outlets are used a lot in commercial construction and other non-living areas that wouldn't require TPO's I think you'd have a harder time finding 20A TPO's. But it looks like they're available online. And yeah, code varies even between Seattle and Spokane so definitely different code if you're in Canada.

ben62670 wrote: »

For a while the plugs were installed "upside down" because the ground would be on top in case something got between the plug and the outlet. It would hit the ground first.

Yep, that's the idea... if you've got a plug that's pulled half-way out and something conductive falls on it and hits it on the prongs, you'd get a short, but not if the ground is on top.

jcandy

On3s&Z3r0s wrote: »

Yep, that's the idea... if you've got a plug that's pulled half-way out and something conductive falls on it and hits it on the prongs, you'd get a short, but not if the ground is on top.

This approach is indeed safer, and some installers still do it this way. On the other hand, in California, an upward-ground is often used to indicate that the receptacle is switched.

BtrSound

I know that this is not quite the same topic, so i apologize if someone gets offended.

I am rewireing my home and entertainment center. I was going to run 1 20 amp outlet and line to my built in just for the amp and one for all my other componets (my television is on it's own amp on the other wall).

I am thinking about using a power conditioner, but am new to that as well. Can one power conditioner power all my componets and the amp? Is this a good practice? Should I buy two power conditioners? What the heck do I do with those things?

disneyjoe7

If it was me dedicated 20amp receptacle, feed with a 20amp circuit breaker and 10/2 romex. Need more add more, just me. IMHO

On3s&Z3r0s

BtrSound wrote: »

I am rewireing my home and entertainment center. I was going to run 1 20 amp outlet and line to my built in just for the amp and one for all my other componets (my television is on it's own amp on the other wall).

I am thinking about using a power conditioner, but am new to that as well. Can one power conditioner power all my componets and the amp? Is this a good practice? Should I buy two power conditioners? What the heck do I do with those things?

Unless you're planning on running some enormous monoblocks, one 20A circuit should work fine for everything. (I'm not sure I understood the part about your TV being on a separate amp, unless you're talking about two systems, one for HT and one for 2 channel?)

That said, if you think you might be doing serious upgrades down the line, the time to run the wires is before the wallboard goes up. It's a cheap thing to do if you have room in your service panel for an extra breaker.

The power conditioner thing is somewhat of a separate question and has enjoyed a lot of vigorous debate on this and other forums. I have a Furman with everything in my HT plugged into it, and I've never had any issues, but I think especially with a dedicated circuit, it's overkill. In your situation, I'd plug the amp into the wall (i.e. no surge suppression between it and the juice) and have everything else on some sort of decent but not extravagant power bar just for convenience. If you feel like you have some power problem you need to rectify down the line, that's an easy add whenever. Definitely don't buy two of them. Cheap ones probably do more harm than good, decent ones will have outlets dedicated to amplifiers and a bunch of other outlets for everything else.

jayman_1975

Thanks again for all the info and input. I have passed this on to my bro inlaw. He is going to do two 15 amp runs. Thats it. Its sad really but not as sad as the $25 walmart power bar he uses. Shame.

inspiredsports

ben62670 wrote: »

For a while the plugs were installed "upside down" because the ground would be on top in case something got between the plug and the outlet. It would hit the ground first.

Because someone assumed the "something" always approaches the outlet from the top ??????????

On3s&Z3r0s

inspiredsports wrote: »

Because someone assumed the "something" always approaches the outlet from the top ??????????

Gravity would seem to make that more likely. :cool:

ben62670

BtrSound wrote: »

I know that this is not quite the same topic, so i apologize if someone gets offended.

I am rewireing my home and entertainment center. I was going to run 1 20 amp outlet and line to my built in just for the amp and one for all my other componets (my television is on it's own amp on the other wall).

I am thinking about using a power conditioner, but am new to that as well. Can one power conditioner power all my componets and the amp? Is this a good practice? Should I buy two power conditioners? What the heck do I do with those things?

Most amp manufactures do not recommend using a power conditioner.
Ben

Tour2ma

On3s&Z3r0s wrote: »

Gravity would seem to make that more likely. :cool:

WAAAAaaaaaaa....

Was wondering 'bout this. Outlets are all upside down in my "new" home.

Bit of a PITA for things like a CO Monitor...

Polkie2009

Here's a twist, Smarthome makes outlets that you can rotate 360 degrees to get the perfect angle for you:)

BtrSound

On3s&Z3r0s wrote: »

Unless you're planning on running some enormous monoblocks, one 20A circuit should work fine for everything. (I'm not sure I understood the part about your TV being on a separate amp, unless you're talking about two systems, one for HT and one for 2 channel?)
.

Basically, since I an rewireing my home anyway now is the time to do it. The only reason my TV has a dedicated circuit is because I ran a new line and outlet to put it above my fireplace so I figured it was the way to go. I am also building a custom built in shelf for my componets, which will have new built in outlets. That is another reason I am running another 20 amp fuse. My next project is finishing my basement, with an actual theater room as well, and it will be more difficult to change things down the road. It is easiest if I run everything once and do not have to worry about it after finishing the basement. I can get a 2 20 fuse and run seperate outlets fairly easily, which is why I was thinking about having seperate outlets for the amp and the rest of my componets.