Power line question


I live in an apartment building that's relatively new (built in 1993). There are no visible power lines attached to the building, which leads me to believe the power lines are underground. The building has a dedicated line for air conditioners. I know very little about power outlets, wiring, amperes, etc. All I know it's 115 volts. Here's my question. I will be replacing my tube integrated power amp with tube monoblocks producing at least 150 watts per channel and a tubed preamp. I have seen occasionally discussions about the demand on the power line electronic equipment makes and parameters for dedicated lines and such. Should I worry about blowing fuses or overloading the power line with my new amplification? My gf and I triggered circuit breakers a few times in the past by using hair dryers simultaneously in our respective bathrooms, but once we stopped that practice, no other mishaps occurred. I have a basic power conditioner with 4 outlets, but that's about it. With my less than rudimentary knowledge of power delivery, I wouldn't even know where to start to answer my question so I thought I'd start here. Thank you for any advice.
actusreus
Each circuit in your apartment will be 15 amps. If you determine the power consumption of your 2 amps and pre-amp - and they exceed 10 amps or so, you may have an issue, as the line you use will likely be shared with other stuff in the apartment.

Generally, getting into high powered mono blocks is something that deserves dedicated lines - something not doable in an apartment. Popping a breaker will happen if the load on one line exceeds 15 amps. The heaters in hair dryers use a lot of amps, for example, as do space heaters, refrigerators, portable AC units, microwave ovens (and power amps). Best you can do is a little math with what's on the same line from the breaker panel, add them up and see what's left for your amps.
Thanks Meiwan. How do you determine the power consumption at a given time in a circuit? I looked at the hair dryer and it states volts, watts and Hz, but not amps. No such info is listed on the manufacturer' website either. The sticker on the breaker panel says "Mains Rating 125 Amp Max." I assume this does not mean my apartment. The only thing that would be in use while I listen would be the refrigerator, laptop and the TV set, most likely.
Divide the watts rating by the volts...that will be the amp rating. Likely around 10 amps. You will need to find the breaker that turns off the wall plug that the stereo will plug into. Turn the breaker off. Then see what isn't working to determine what is fed by that breaker.
Actusreus,

Easy as PIE....

P = I x E

p = power, watts, Va.

I = current, amps.

E = volts

To find (I) divide (P) by (E).

A 15 amp circuit should not be loaded more than 80% continuous load. 12 amps.... Or 1440 watts/Va....
Thanks! Sounds like this should not be a concern unless I'm blowdrying my balding head while listening to Metallica at a high volume...

The monoblocks deliver 150 watts per channel so 300 watts divided by the constant voltage of 115 equals 2.6 amps.
The 150 watts per channel ratings are the output measurements for the amps. Current draw calculations deal with the input ratings of the amps. If you post the make and model of the monoblocks , someone will likely know what the amperage draw is.
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Ska_man, the monoblocks are the Rogue Audio M-180s.

Elizabeth, it appears the apartment gets 125 amps total based on the sticker on the breaker panel. This makes sense as there are eight breakers (four of them locked in pairs).
Rogue Audio shows a main fuse value of 5 amps for an M-150.
They don't have the M-180 info available online. I think it would be safe to assume, for calculation purposes, that adding 20% to the value of the fuse will be pretty close to maximum current draw. So, a pair of M-180,s should be close to 12 amps total current draw.
Elizabeth- Is that " i have 210 amps coming into my apt" some sort of typo? If not, how big is that apartment?
I don't think you will have a problem. My guess is that each amp will consume about 300 to 400 watts each, maximum. That means both amps and a preamp in the same outlet will have as much of a power draw as a desktop computer, monitor and printer.

Look at the owner's manual. Unless it specifically calls for a separate outlet, you will have no problems. The UL listing means it is safe for standard 15-amp branch circuits.

The reason that two hair dryers tripped circuit breakers is because both draw over 2400 watts, exceeding the 1800 watt maximum that a 15-amp circuit breaker protects (maybe there are lights on that circuit as well). There is no way your rig will exceed 1800 watts -- unless those hair dryers are used on the same circuit.
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Thanks guys; this helped a lot. I certainly understand much more about circuits and power usage now.

To go back to Elizabeth's advice, my breaker panel actually lists which circuit powers what in the apartment, so they did the job for me. Interestingly, the oven has a twin breaker of 40 amps, the dryer a twin of 30 and the AC a twin of 20 (two switches each but bridged so that operate as one). It appears the lights in the apartment (judging from the list, this includes the power outlets), have a circuit with two separate breakers, each stating 15 on them. Does this mean there are actually two circuits of 15 amps each? Funny how fascinated I am now by the topic. I just might talk an electrician! Thanks everyone.
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It appears the lights in the apartment (judging from the list, this includes the power outlets), have a circuit with two separate breakers, each stating 15 on them. Does this mean there are actually two circuits of 15 amps each?
03-07-11: Actusreus
Actusreus,

Are you sure the building was built in 1993?
You should have a bare minimum of (2) 120V 20 amp branch circuits for the kitchen and at least (1) 120V branch circuit GFI protected for the bath room/s.

What you described is more representative of the 1960s and earlier....
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Jea,
I think I do. Here's the breakdown:
40 amps (bridged twin) for the oven
30 amps (bridged twin) for the washer/dryer
20 amps (bridged twin) for the AC
15 amps for the living room heater
15 amps (twin, not bridged - still confused what this means) for "lights." This one probably controls all of the outlets, but cannot test in now unless I want to incur my gf's wrath.
20 amps (twin, not bridged) for small appliances (fridge and kitchen outlets above the counter)
20 amps (twin, not bridged) for the dishwasher
20 amps (bridged twin) for the bedroom heaters

Not sure which one controls the bathroom outlets, however.
Actusreus,
Jea48 has more knowledge on this subject than I do. So, if
I say or recommend anything that differs from him, please follow his advice. That said....the bridged breakers are for 240 volt branch circuits. The twin (not bridged) breakers are for 2 independant 120 volt branch circuits.

The wall outlet that you want to plug the stereo into, will be fed by one of the 20 amp (non bridged) breakers.
With a 20 circuit you shouldn't have any problems running your stereo. To make sure, as I mentioned earlier, turn off the breaker that powers that particular outlet and check to see what else is on the same circuit. While doing so remember that each 20 amp breaker lever controls one circuit. Don't turn 2 off at at time, it will skew your results.
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Actusreus,

Thanks for the additional information....
Jim
Considering that both the M120's and the 250W Apollo's also have 5A fuses, I wouldn't consider that an accurate draw.

Do you really need a dishwasher? Ever considered a portable dishwasher? Frees up a dedicated 20A circuit... More cupboard space... You can sell that.
Jim & Elizabeth -- I think you are miscommunicating :-)

A two-pole 60 amp main breaker is referred to as "60 amp service," but means that 120 amps would be available if all of it were used at 120V, or that 60 amps would be available if all of it were used at 240V.

Best regards,
-- Al
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Do you really need a dishwasher? Ever considered a portable dishwasher? Frees up a dedicated 20A circuit... More cupboard space... You can sell that.

Ha, ha, indeed, I do not need one! In fact, it has never been used since we moved in. However, my dedicated listening room is the farthest room from the kitchen. It's not a big apartment, but I cannot run an extension cord from the kitchen to the listening room; my gf would never allow it and it would look ridiculous as the cord would have to be run through the living room. Re-wiring is not an option as it's a rental.
Sorry to be reviving this dormant thread, but I have some additional questions that I'd like to ask to solicit your opinion.

Is it possible to have a truly dedicated power line in an apartment building? It seems that one could rewire one of the circuits perhaps to only feed the system, but wouldn't that line be still shared with the rest of the tenants in a general sense? In other words, if a 20 amp circuit in my apt feeds small appliances in the kitchen, would using it for the system only be what people refer to as a "dedicated line"? Since other tenants also have that circuit and might be using their blenders and microwaves at the same time as I listen, would that mean it is not a truly dedicated line? How isolated are individual circuits in an apartment from other tenants' circuits?

My neighbor, who also happens to be an audiophile, had an electrician rewire his air conditioner line to 115V for use with his system. He calls it a dedicated line, which it most likely is during the winter months, but if the rest of the tenants living on the floors below him and in the rest of the building are blasting their ACs in the summer, wouldn't that affect his "dedicated" line?
Actusreus, a dedicated line only insures there is nothing else on that breaker or line. If you have bad ac... you still will have bad ac.
Sure. Aside from that, are you saying that mine circuits are isolated from my neighbors' so that their usage has no effect on mine whatsoever? I noticed my kitchen light flickers barely noticeably sometimes; is that a sign of bad ac, heavy demand in the building, or something else?
Our power lines are underground and my audiophile neighbor agrees with me that we have a pretty good quality of current, especially late in the evening and at night for obvious reasons. I'm just exploring the benefit of dedicating a line in an apartment building with neighbors sharing walls and ceilings.
Get a Kill-A-Watt meter and start measuring stuff. worth about 20$

The callouts on an amp, unless it is a class'a' amp, are max ratings and will usually be much lower.