When is one 20 amp circuit not enough?

NewHTguy

Need some help from the electronics experts. Right now my entire living room is on a 20 amp circuit. I have not had any trouble running what you see in my signature plus a cable box and Samsung 52 inch LCD. Would adding a 250 wpc 2-channel amplifier require more than the 20 amp circuit can give?

ben62670

Although your CB may not trip you may experience a voltage drop, and depending on what else is on that circuit you may want to add a dedicated outlet. Lights., and other things may induce noise. YMMV
Ben

brody05

20 amps is in the vicinity of 6000 watts (or at least it is in NZ with 220v), I guess amps is amps though. Most systems wouldn't be using near that.

Sherardp

If its cheap to do then sure add another. I run 5 20amp breakers in my dedicated room.

NewHTguy

Sherardp wrote: »

If its cheap to do then sure add another. I run 5 20amp breakers in my dedicated room.

I don't know how much it would cost. There would be a significant psychic cost imposed by my girlfriend who already thinks I'm crazy.:D

NewHTguy

brody05 wrote: »

20 amps is in the vicinity of 6000 watts (or at least it is in NZ with 220v), I guess amps is amps though. Most systems wouldn't be using near that.

Is the calculation, ROUGHLY,
watts = amps x voltage
I assume there is more to it than that, but is that a good approximation?

NewHTguy

ben62670 wrote: »

Although your CB may not trip you may experience a voltage drop, and depending on what else is on that circuit you may want to add a dedicated outlet. Lights., and other things may induce noise. YMMV
Ben

Thanks Ben. Right now a couple of CFL lamps are all I have.

ben62670

You are fine. That money could be used better elsewhere. Tell your GF that you decided to get this(whatever it may be) instead of a dedicated outlet:)
Ben

disneyjoe7

Wait doesn't CFL introduce noise on the line? Wouldn't anyone above you average AVR / Speaker setup be benefited with a dedicated outlet or two?

brody05

some real power hungry amps would certainly benefit from its own line, I have one for the Verastarr.

But most houses run more than a few power points off the same breaker, throw a switch at the power board off and see how many plugs go down.

We have an induction hob that needed a 30 amp one, talk about power hungry, it uses more than the stereo at 7200 watts :eek:

Not sure about the conversion formula, just remember that number from when the hob was wired up a couple of months ago.

NewHTguy

Lasareath wrote: »

When I power my whole system at full blast it draws around 5amps

That's all? Do you have a powered sub and amp?

disneyjoe7

Sal,

My thinking is that display is average not peaks where if you're pushing like that I'm sure you can draw something like 16amps or so like my self.

treitz3

When is one 20 amp circuit not enough?

To answer the question above, when the lights dim considerably when lettin' loose or the circuit breaker pops more than once a month. If you are running more than 20 amps on that circuit.

Another circuit wouldn't hurt and might help the overall performance of your system depending on what you have running but IME, it isn't necessary unless the above conditions happen.

VR3

Ive ran 5 amps, a tv, cdp, dvdp, consoles, preamps, receivers, powered subs, computers on one circuit with zero problems...

treitz3

Trey, you forgot the fans......

mmadden28

I've had my whole HT system (see my sig) on a single 15A breaker. Max current draw when running full force? 11.4 amps (IIRC). Never tripped, but the lights dimmed whenever the amp turned on. My entire Family room was also on that same circuit, including the ceiling fan, and all the lights. The voltage reading at the HT would always fluctuate.

My HT is about 100' from the main panel and I was getting 111.8VAC at the power conditioner when the voltage at the panel was 121.8VAC. Of course that is sort of expected when pulling 11+ amps across 100' of cable. Huge Voltage drop. I couldn't help but wonder if I was starving my setup of some full flow juice...

I've since upgraded by adding two additional 20A circuits with 10awg Romex (10awg to help further reduce the resistance/Vdrop for the long distance). One circuit for my amp, and one for the rest. My lights don't dim anymore and I now have a steady Voltage reading at the HT setup (and with minimal if any VDrop). That's gotta be doing something good for the system. :cool: Yeah I may have gone over kill and spent more than I needed to on cable. I could have just installed a single additional 15 or 20A circuit, but I do stuff like that ...:o I wanted to give my amp its own, I wanted to give the rest of the HT its own, and not chance any noise induced onto the circuit from my lights, CFLs, or my ceiling fan.

You really don't want to run your circuit close to max-it needs breathing room, esp for dynamic demands from your amps. Its possible my setup was pulling more than 11.4A max, but my meter wasn't fast enough to catch it if it were.

I would try the setup with the new amp added on your existing circuit and see how it goes. See if your lights dim. If you're able, measure the voltage at the panel and at the HT. Measure the current demands of your setup. Take it from there.

disneyjoe7

Sal, I'm going by an KillAWatt meter, not your typical audio filter, can you place one of these at the wall and compare but I sure one is an average where one is more peak value. But all in all Lights dimming is the best test, sorry to say have a lot of that, at Christmas with tree lights the bass note dimming light thing is kind of funny.

mmadden28

With my Kill-a-Watt, I found that my prelit Christmas tree was drinking 400 frickin watts! :eek:
I don't leave that thing on all night long anymore.

FYI, for my measurements-I used my Belkin PF60's meter, my Kill-a-Watt and a Fluke Clamp-on VOM at the panel and at the outlet.

disneyjoe7

Well my Kill a Watt, I found that my listening to my xm radio in the morning was 250 watts a hour. :eek:

ben62670

I had 3 GFA-565 Mono blocks on one circuit, and we were cranking to the tune of 123db peaks. The PFGA boys were there, and lightman was looking on. The voltage never dropped. This was right out of the wall socket. The wire run to the panel was only 25 feet in the wall. Like mmadden if the voltage is not dropping, and you have no noise you are doing pretty good.

NewHTguy

Many thanks for all of the good feedback. At the very least it sounds as if I should give it a try as is. Thanks again. Good stuff.

Unknown

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hypertone

20 amps on a 120v circuit is 2400 watts.