I am confused about 15A and 20A current.


Electrical Expert:

(1) How do I get 20A out of the main power line in my house?

(2) Is it typically setup 15A ?

(3) Is there a conversion unit (15-20) available?

The reason that I ask is that as soon as I turn on the Rotel RB-1090 (rated 380W) the circuit breaker breaks.
Thanks,

-TT
midfi
Take the 15-amp circuit breaker out of your box and replace it with the same brand of breaker that's 20 amps. Email if you need directions for the removal and switch.
You need to have a circuit that's capable of 20A as well as a breaker otherwise you'll end up defeating the point of having a breaker. While I'm pretty sure that standard 12/3 Romex is good for 20A, I'm not qualified to say for sure.
Do not just replace the breaker! In order to use a 20 Amp breaker you need a minimum of 12 gage wire. If the current breaker is 15 Amp then most likely the circuit is wired with 14 gage. I do not recommend you do anything to this circuit. To be honest if you don't understand the current rating you should not be messing around with the circuit. Not trying to be mean spirited, just trying to save your house and/or your life! As for the amp tripping the breaker, it if is the only item on the circuit there is something wrong with the amp. If there are other things on the circuit you should either use another exisiting circuit or have an electrician put another. preferably dedicated, circuit.
Unless your wiring is a minimun of 12 gauge (14 gauge is smaller) you cannot just change the breaker to a larger size. If you have 14 gauge wiring on that circuit try replacing the existing breaker with the same brand 15 amp breaker as breakers can wear out over time. If you still have a problem after the replacement, you're going to have to find another circuit with more reserve capacity or install a dedicated circuit.
I never stopped to think about the possibility of an older home (etc) with old or small gauge wiring. One needs to be certain that the wire is at least 12-3. The posts above this post are correct and bring up some excellent points that I failed to mention. Another reason that I really like Audiogon :-)
DO NOT REPLACE A 15 AMP BREAKER WITH A 20 AMP BREAKER!!! Alexanderj is right! Remember the old "penny in a fuse box" trick, in the days before breakers? Unless you can confirm that your circuit will adequately handle 20 amps, you run the risk of an electrical fire that can consume your entire house...like the fuse box situation that I just described (saw that happen one time, although the house wasn't lost, there was electrical damage done, before the main 50 amp buss fuse blew!) Funny, I just had a conversation about circuit breakers the other day. They can oxidize over the years, and should be replaced every few years (for your audio circuit). Your Rotel's 380 watts should not trip a breaker when you power up. Assuming a doubling peak at start up (760 watts), and even with a low power supply to your circuit (110 volts), you will only draw about 7 amps at power up. Are there other high amperage appliances on your stereo circuit? This could be your problem, but I would bet on an old cruddy breaker. Or there might be a problem with your amp, but usually, the internal fuse(s), will blow, NOT the circuit breaker.
All:

Thank you a lot for all of your comments; they are great suggestions and are helpful information.

I will have to return the Rotel and leave the circuit breaker the way it is, then try another amplifier. I heard the Rotel is a very good amp, but it takes so much effort to make it working.

Thanks again.

-TT
Now, now don't take the Rotel back. This amp can't be drawing that much juice. What all else do you have plugged into this circuit? Or what all else shuts off then the circuit breaker pops? You might be able to simply rearrange things in your home and place them on different circuits.

Marty
Midfi,

Don't return anything just yet. Maybe I'm off base here, but it sounds to me like you are tripping the breaker with inrush current. When you first power on that amp, all the caps inside must charge and do so very quickly. This can cause a perfectly functioning circuit to trip as the initial momentary current exceeds the breaker's rating. However, those same caps discharge slowly unless drained.

I would suggest you try this: Power on the amp (with your pre off). If the breaker trips, turn the amp off then reset the breaker, then turn the amp back on. My guess is that after the breaker trips once (maybe twice), it doesn't trip again...until you turn the amp off for awhile and turn it back on. Instead of turning the amp off, leave it on all the time...it's better for the longevity of your electronics, anyway. Hope that helps and let us all know if that works...
Could the tripping maybe be from a worn out circuit breaker ?

I had a circuit breaker that seemed to trip too easily so I replaced it with a new one of the same vaule. The problem went away.
I have just completed development on a 15 to 20 amp "current upsampler" with breakthrough, patented, capacitorization technology. Let me kow if you are interested.
Enough has been written about the reasons why one should not change a 15 amp breaker to a 20 amp so I'll just add my 2 cents about a comment on 12-3 for the 20 amp circut. 12-2 is all that's needed. 12-2 has a black and white conductors plus a bare wire for ground. 12-3 has an additional red conductor. Small point sure, just don't want someone to look at their wire and think it's wrong.
Sorry, I have been spending time work on the yard lately because our house afftected by Isabel. Too many downed tree.

Thanks all for your suggestions. I tried every thing, and the amp still tripping the breaker every time I turn it on.

I check out the spec on Rotel web site, and yes, it consumes 17 Amp input; therefore, it requires 20AMP outlet in order to get the amp function.

Again, thanks all.

-TT
Despite the fact that this is an 80+ lb beast with casters on the back (!), the back panel drawing and the owners manual state the power consumption as 800W (6.9A@115VAC). Points off for the Rotel WebSite, since their spec sheet says 1200W. Two out of three, I vote for 800W...

There are way too many unknowns in the post to be able to comment correctly. If the amp comes with a 20A IEC (highly doubtful), and a 20A cord for the US market, you wouldn't be able to plug it into a 15A receptacle, due to NEMA plug/ receptacle configurations. There isn't any information on the age of the house, and what edition of the NEC it was built to, if it was at all.

The owner's manual has the following note:
"The RB-1090 has a built-in surge attentuator to prevent opening the electrical circuit breaker or fuse at turn on." It sure smells like an amp problem, but I'd have the whole panelboard looked at first. As in, replace the whole thing, or at least have all circuit breakers replaced. By a *real electrician, of course...
Your Refrigerator could possibly be on a 20 amp circuit. Try plugging the whole mess into that outlet. If that circuit breaks, then that tells you something.
Refrigerator, plus kitchen counter tops, washing machine, plus typically one in the dining room since at least the 1975 NEC.

Unless someone has removed the amp's fuseholder and wirenut'ed the leads together, the amp fuse will blow *much sooner than the branch circuit C.B. (Time-current curves...)
You cannot just swap out a 15A breaker for a 20A. You must have at least 12/2 romex running from panel through the walls to accommodate the 20A breaker. When you just swap out breakers as above, you will over heat the romex wire, being that the 15A existing circuit is wired with 14/2 romex. If there is room in panel, then add a new 20A dedicated circuit for the hifi, which entails running new 12/2 romex from panel to new receptacle, which by the way must also be 20A. Yes, a bit of work indeed, but safe and solves the issue. Lastly, most prior answers suggest 12/3 romex which is not correct for the application. All you need is 12/2 (black/white/bare copper ground). The 12/3 contains a third conductor, red, and is typically used when installing a three way switch.