Stupid electrical question

[vaughan5]

How many Amps in a standard household outlet ? And how many watts= 1 Amp. Just curious as to how much I can plug into an outlet.

[Altpers0na-old]

the outlets not really got a rating, it does ,but its not going to be a problem, the breaker or fuse that feeds that outlet , and the other things connected to that breaker/fuse are the things to consider.

amps are a measure of electron flow. any watts = 1 amp..

Power = watts
Voltage x amps = power

120 volts x 15 amps = 1800 watts.

electrical stuffs, have an amp rating, or should have one listed. it tells how much 'current' that item will draw when supplied w/ the proper (also listed) voltage and how much wattage that should total.

watts also = heat (waste energy)

watts , horsepower, btu's are covertable like yards to meters.

http://en.wikipedia.org/wiki/Power_%28physics%29

so, er , just what do you plan on running on one outlet?

[kgolem]

A typical household circuit will provide 15 amps in total to the outlets on that circuit. That means that you cannot draw more than 15 amps at any time from the total of the outlets on that circuit (thats a lot).

Power is calculated by multiplying the current (amps) by the voltage. So a 15 amp circuit can deliver 15*120 = 1800 Watts.

A great deal of power.

[kgolem]

You beat me to it Altpers0na

[WiscSea]

Yeah, most houses are wired with 15 amp outlets. However, 20 amp isn't too uncommon. You can tell by the outlet. 15 amp look like this | | 20 amp are kind of like this -| |

They have that extra little grove on the left side. Before you bank on it being a 20 amp circuit, check the breaker to make sure it is 20 amp and if possible the wire to make sure it's 12/2.

[vaughan5]

Thanks for the help..
So how many watts would a 115V 3.4 Amp chiller use ?

[vaughan5]

If I read the posts corectly..then 115V x 3.4 Amps = 391 watts?

[WiscSea]

Ohms Law Calculator

http://ourworld.compuserve.com/homep...en/ohmslaw.htm

[samtheman]

Originally posted by vaughan5
If I read the posts corectly..then 115V x 3.4 Amps = 391 watts?

You must also understand that when motors start, they take as much as twice thier normal amps. So if you have a circuit loaded to say 10 amps and add a 3.4 amp motor, it will probabloy blow the circuit every time it starts. You need to keep the circuit loading at about 2/3 of the rated capacity to allow for these type surges.

[BeanAnimal]

Originally posted by WiscSea
Yeah, most houses are wired with 15 amp outlets. However, 20 amp isn't too uncommon. You can tell by the outlet. 15 amp look like this | | 20 amp are kind of like this -| |

They have that extra little grove on the left side. Before you bank on it being a 20 amp circuit, check the breaker to make sure it is 20 amp and if possible the wire to make sure it's 12/2.

Not always the case.

It is perfectly common (and legal) to terminate 20 AMP branch circuits with outlets rated at 15A. So you may have 20 AMP branch circuits that have straight bladed recepticles on them.

That said... 20A branch circuits are not that common in residential settings, other than where required (kitchen, dedicated laundry outlet, etc).

Bean

Bean

[WiscSea]

Originally posted by BeanAnimal
Not always the case.

It is perfectly common (and legal) to terminate 20 AMP branch circuits with outlets rated at 15A. So you may have 20 AMP branch circuits that have straight bladed recepticles on them.

That said... 20A branch circuits are not that common in residential settings, other than where required (kitchen, dedicated laundry outlet, etc).

Bean

Bean

True enough, but you are still limited by the outlet in that case (unless you change it). In fact, all of my DYI wiring at my house is done with 12/2 wire even if the breaker and outlet are 15 amps. I feel it's a little safer, plus it's an easy upgrade if I need 20 amps down the line. Also that way, I only need to keep on kind of romex on hand.

[vaughan5]

Thanks for the link wiscSea.
A lot more complicated than I thought ! I plan on purchasing the reef keeper 2. It comes with an 8 socket strip for the controller. Seems like its asking for trouble to have a Chiller, 2 external pumps, tank lights, fuge lights, powerheads, fans and a heater all pluged into one outlet.
Any concerns here ?

[stugray]

Just FYI for everyone:

AC power calculations are NOT as simple as P = V * I.

For simple AC power calcs ( resistive loads ) a closer approximation is

P = ( V * I ) * .707 which is closer to the RMS values.

In addition, if the thing you are running has a reactive component ( like AC motors in a chiller ), then the power is very complicated.

In fact, I could build a device that runs on 120 Volts, draws 15 Amps, and consumes NO POWER ( however it couldnt perform any work ).

Stu

[BeanAnimal]

Ohh boy... how did real and reactive power get tossed into this? Power factors may be hard to calculate on real world complex laods, but in most cases you can come pretty close with ohms law (esp when you are looking at your entire panel load, not a single device).

The "power meter" outside the house is a lot harder to "fool" than most people think. In any case, stu you wanna peek at my "fool your electric meter" project.

Bean

[stugray]

Bean,

"how did real and reactive power get tossed into this?" - just trying to keep it honest. The good news is that if you do the simple P=VI calc, then you'll have the worst case power with built in margin.

"stu you wanna peek at my "fool your electric meter" project."

sure, PM with a link. I have heard about it, & I get the concept, but I ve never really looked into it. Besides, I thought the power company fixed the 'foolling' part with the newer meters...

In our hobby it might be useful to have a 'lighting filter' that reduces my electric bill ( wink wink, nudge nudge ;-)

Stu

[BeanAnimal]

Stu....

I spent countless hour looking into these "devices", I think as a teenager I even spent money on a set of plans!. The old style meters can be fooled (if thats what you want to call it). The new digital meters are much better equiped to deal with different power factors (but it is unlear if this is automatic or not). It should be noted that many large building have "power factor" correction equipment (capacitor arrays) to ensure that the power bill is not skewed.

In any case the problem with "fooling" a meter is that fact that your household load changes constantly and these devices are not "automatic" and can't correct for the changing load. Though I imagine with a computer and some intimate knowledge of power meters, one could shave a few bucks of of their bill each month.

A good *hint* would be to look into why the power company wants both legs of your 120V service as balanced as possible and all of the power returned on the neutral.

Bean

[kgolem]

Originally posted by stugray
Just FYI for everyone:

AC power calculations are NOT as simple as P = V * I.

For simple AC power calcs ( resistive loads ) a closer approximation is

P = ( V * I ) * .707 which is closer to the RMS values.

In addition, if the thing you are running has a reactive component ( like AC motors in a chiller ), then the power is very complicated.

In fact, I could build a device that runs on 120 Volts, draws 15 Amps, and consumes NO POWER ( however it couldnt perform any work ).

Stu

In this situation the Household voltage used in the calcualtions (120 Volts) is an RMS value and the "root of two" multiplier is not necessary.

And I agree with other statements here that reactive components in the typical household , even with several motorized loads, add a negligable effect to the real power consumption.

[Altpers0na-old]

ok, so now can we move on to valence shell? please....

so your list of things to consider is something like this...

the breaker that your outlet is connected to is rated at ....

what outlets/switchs does that breaker feed.

what is connected to those outlets and switchs.

how much current are those thing using.

that is to say, a microwave and a toaster oven can share a breaker, but might pop the breaker every time there turned on at the same time....

if your tank has enough electrical stuff to warrent its own breaker, well then there ya go...

depending on the stuff that your breaker is feedign id say, plug away , and it will pop when its had enough. unplug that last couple things and find them a new breaker. this is not the proper way to do it, but it how i do it on non critical stuff...

[BeanAnimal]

Sorry... I don't do subatomic particles until after 10 PM. So please...

In any case I think the OP question was already answered. It is as easy as adding up the wattage of each device on the circuit and comparing that to the breaker size. Using Voltage X Amps will get you close enough. LARGE pumps or LARGE ballasts will draw more at startup, so take their listed wattage and multiply it by 1.5 or so. Pretty straight forward without having to guess.

[vaughan5]

Thank you for the last two simplified answers for us idiots !

[SteveOhh]

Originally posted by BeanAnimal
In any case, stu you wanna peek at my "fool your electric meter" project.

Bean

The ol' "flip your meter upside down trick" so it runs backwards?????

Steve

[BeanAnimal]

sorry steve, nuch such thing as a backwards runjing meter, though I am sure plenty of people have tried!

[schristi69]

Originally posted by vaughan5
Thanks for the link wiscSea.
A lot more complicated than I thought ! I plan on purchasing the reef keeper 2. It comes with an 8 socket strip for the controller. Seems like its asking for trouble to have a Chiller, 2 external pumps, tank lights, fuge lights, powerheads, fans and a heater all pluged into one outlet.
Any concerns here ?

It is not just one outlet, but one CIRCUIT. For the typical sockets in your house, say your living room for example, you will have miltiple sockets on a circuit which goes to one breaker. Plugging in all of your devices into multiple sockets on the same circuit is the same as plugging all of your devices into just one socket. You have to account for the power draw of all devices on the CIRCUIT. This is why many, if possible, wire their tanks with 1 or more dedicated circuits just for the tank. You could have everything running fine plugged into one or two sockets near the tank and then turn on a light across the room and poof, you trip the breaker. You might want to take some time and map which outlets are going to what breaker.