The Lightbulb Theory

[KronoLeginaire]

I wqas talking to a electrician and he said belive it or not a simple light bulb, in many cases, takes up more juice(electricity) than electronics like computers.

Is he right?

[highrisemech]

The PC itself yes. The Monitor no.
Let me correct myself a little a Pc is about 230 watts, that would be 2 and a half bulbs consumption wise.

[Nuclear Krusader]

I don't think so. Did he specify those conditions?

[morriswindgate]

It actually could. A 100 watt light bulb uses 100 watts to heat the filament when it is new and the amount of watt increase until it burns out.
A computer on the other hand may have a peak power usage (When everything is running inside) that is 2 to 3 times the bulb, but the power usage will fall off dramatically during idle times.
The monitor on the other hand does use a steady amount of electricity when on.

[KronoLeginaire]

Originally posted by highrisemech The PC itself yes. The Monitor no. Let me correct myself a little a Pc is about 230 watts, that would be 2 and a half bulbs consumption wise.

So the monitor could pull allot of weight around?

Nuk. - he did not specify any conditions but let me explain the question which I initaly asked him which resulted in the 'lightbulb theory'


QUESTION:

The attic is only accible through by bedroom becuase the door to the attic is in my room. In my room in only 1 outlet. In the attic there are two. I have a TV, Light, Xbox, and a few other minor things in my room - all on that one outlet. I want to move my PC to my room for the summer but am concerned that all that stuff on one outlet would be a fire hazard, dangerous, ect. I was thinking about ruinnning a orange industrial extention cord (the kind construction workers use) from a outlet in the attic down to my room exclusivly for my PC and its stuff to use. My question is, since the second floor and the attic are on the same circut breaker would this cause any problems in the direction of a overload?

[KronoLeginaire]

So wouldn't there be a device the detects and monitors the rise in wattage to a set point and then turns the power the light off and alerts the owner that its time for a new bulb or similar?

[highrisemech]

That would depend on how many AMP's the circuit breaker and the wire on the breaker were rated for. Which I believe is no problem this is done quite frequently. The best way to do it though is to shut the circuit down, tap into the the box that the outlet is mounted into with some good BX wire then run it to a new box with a new outlet. Or if your worried about to much on one circuit tap from another. Also there is probable an available port in your breaker box to run another dedicated circuit. But this should be done by an electrician.

[morriswindgate]

In the USA all construction for the last 30 years or so has required that outlets be a 20 amp service. This means that you can keep a constant load of about 25amps on the outlet with no problems or heating.

[KronoLeginaire]

yeah, i could do that extraoutlet thing but no way would I be allowed to do so. I'm better off with my inital ideal.

[KronoLeginaire]

I know one thing for sure. When I get my own house, it will have a very robust and dependable electrical system and high quality grid structure, sure to withstand the test of time.

[juppy]

The breaker should handle it if its a decent size (it probably is unless your house is pretty old). My brother recently moved into my grandma's old house and the entire south half was on one 30 amp breaker (1 bedroom, bathroom, dining room and kitchen - not the fridge though). Since this was the side of the house he was going to be putting his computer on and the fact that we rewired the bathroom with more lights, we decided it may be too much. Luckily for us though, we had a ceiling fan that he didn't need and it was on its own breaker so we just halved the south side up between that breaker and the one it all was on. So, if its a good sized breaker then, yeah, you could get a good sized extension cord and plug to the attic. Just be sure the cord is heavy enough to handle what you're putting on it without getting hot and causing a fire hazard.

[KronoLeginaire]

yeah, that cord is pretty good. As I said its the kind constuction workers use outdoors and indoors with powerful equpment such as saws, drills, ect. 3-prong too. MY house is not 'new' either but it was renovated for new living. As I remeber, my pal who lives up the street said that at one time this place was abandoned. Oh well, after the somputer and stuff has been running for an hour or so i'll go around to all outlets and circut breakers involved and check for any suspicious signs of hazards such as burning odors, noise, smoke, heat, ect.

[jamesrpm]

I have to respond

"In the USA all construction for the last 30 years or so has required that outlets be a 20 amp service. This means that you can keep a constant load of about 25amps on the outlet with no problems or heating."

Nowhere in the National Electrical Code does it say standard plug circuits must be #12 wire or a 20 amp circuit. They can be ,and in my installations are that size .But there are lots of spec. houses and rentals out there with #14 gauge ,15 amps circuits in them. Only circuits required to be 20 amp are kitchen including the appliance circuits, bathroom outlets, and laundry circuits.
You may be able to load #12 wire to 25 amps but there is no 25 amp breaker so it would trip the standard 20 amp breaker if you did .The breakers are sized to protect the wire so adding a larger breaker to an overloaded circuit is very dangerous! Also most of your residential outlet devices are only rated for 15 amps .

As for using an extension cord to run another outlet. Is it on a seperate circuit or is the one in the attic fed from some other room in the house that may be overloaded already? A heavy cord like they use in construction means little , check the gauge of the wire . Not the size and heft of the jacket. Personally it is a poor idea to run an extension cord through through the attic for any reaon they arn't made for the constant heat they would be exposed to up there. And just like in computer chips high heat means high resistance and a fire hazard will result. Hope you reconsider and just get a load test done on the circuit in your room. An electrician can clamp a amp meter on the circuit to your room turn everything on and see what the draw is and tell you how many amps are available to that circuit. plus have him check the grounds to see that the power you are getting is as clean as it can be.

Not meaning to offend anyone , but I am a Lic. electrician and retired vol. firefighter

[juppy]

Originally posted by jamesrpm The breakers are sized to protect the wire so adding a larger breaker to an overloaded circuit is very dangerous!

A little clarification here: I wasn't implying that he could use the same wiring and just add a bigger breaker and be okay.
Obviously that would not be the case as this would still present a fire hazard.

As for using an extension cord to run another outlet. Is it on a seperate circuit or is the one in the attic fed from some other room in the house that may be overloaded already?

He stated in his second post that the second floor and the attic are on the same circuit. This is why I suggested a heavy extension cord may be a better way to go. If he were to plug everything into the one outlet in his room, that outlet may get hot and pose a fire hazard. By running a good quality extension cord with heavy gauge wiring in it from the attic, the pull on the breaker and the main wire coming to the junction box would be the same, but it would be distributed to two different plugs after that so each one should remain cooler. I do agree with you though on the statement of having an electrician check the line current to see what it is or how much he can safely pull on that circuit. BTW, no offense taken (at least on my part). Better to make sure its gonna be safe. Feel free to jump in anytime on matters such as this....its better than letting someones house burn down because of some bad or misleading info.

[LawyerRon]

jamesrpm,
My experience is that most outlets are 15 amp.

[highrisemech]

I have to agree with Jamesrpm. Most of the circuits in the highrise units are 15 Amps There are 15, 20 AMP breakers. The 30 Amp breakers are for 220 service (Double Phase). You can get an
AMP Probe which clamps over the wire to determine your load on a particular circuit. Some elictrical cords look heavy but in reality the wire in them is thin. These are fire hazards. If you do plan on using an electriacal cord check it's rated load capacity. I still feel in reality you should add an outlet then check the load on the entire circiut with an AMPprobe.

[doctorgonzo]

If I were you, I would put another outlet in your room. One is simply not enough. If you are careful, it isn't too hard.

A 15 amp circuit translates to 1800 watts of constant power. Add up all of the things you plan to put on that circuit and see how close you are to that number.

[juppy]

Yeah, if you can do it, adding an outlet would be the better way to go. Not that hard really. Hardest thing (to me anyway) is getting the wire fished down the wall to the outlet hole. Like highrisemech said, if you DO use an extension cord, make sure the wires inside are heavy enough to handle it. My uncle had a cord that he said some "construction workers" left behind where he used to work, so he brought it home. That thing LOOKED huge, I mean the cord was as big around as your thumb. He wanted me to put a new plug on it for him and when I cut the old one off, guess what? The wires inside were tiny. I mean, maybe 16 gauge, at best (possibly smaller). The rest was just that stringy cardboard packing stuff. Needless to say I told him not to run anything but say a small fan off of it.

[KronoLeginaire]

Yeah, I've changed my mind about that computer in my room stuff. Its better down here but I'm still worried about the load on the house. The reason being is that at time the light may flicker (the type of flicker that is very hard to see, you must stand still and watch it for a while in order to see it.) and you can't turn on the TV, Computer and microwave all at the same time. It seems that they went by floor for each breaker. Not room or special load area (excluding the water heater, and furnace). This electrical system in this house is really screwed up in my opinion, my mother really dosen't care about the concerns that I have about this house. As long as things work she dosen't care. I wish she would take notice though - there could a fire waiting to happen at any second. You guys have seen them stories on the news - one minute the house is peaceful, cool and no signs of problems to the homeowner but then the next minute its up in aball of flames. Then the home owner says "I don't know what happened".

[Charliey]

How many total breakers are in your breaker box? are there only one for each floor plus the stove/furnace/fridge?

[Paul Victorey]

Originally posted by doctorgonzo If I were you, I would put another outlet in your room. One is simply not enough. If you are careful, it isn't too hard. A 15 amp circuit translates to 1800 watts of constant power. Add up all of the things you plan to put on that circuit and see how close you are to that number.

Well, in some cases, you can't add the rated watts for devices, if the devices contain reactive loads. Watts are, by definition, the real component of the power, but there is the reactive power, too, if there is a reactive load. Something which is 300 Watts and has a large reactive component will draw more than 300 VA. His circuit is rated at 1800 VA, not 1800 W. The apparent power (in VA) will always be greater than or equal to the real power (in W).

How important is this? It depends on the types of devices on the circuit and whether or not the devices have circuitry to minimize their reactive load.

BTW, does a 15 amp breaker means it trips when the peak voltage is over 15 amps, or when the RMS current exceeds 15 A? I'd imagine it's RMS not peak current, in keeping consistent with the rest of the measurements.

[highrisemech]

The breaker is spring loaded once it gets hot it trips to prevent an electrical fire. Once you get at or around a 15 AMP load on a 15 AMP breaker it will trip. Most houses come with a 100 AMP service breaker box allowing you to divide the circuits throughout the house. Some house do not even use all of these where as there may be an available port in your breaker box to add a circuit. If one has lights flickereing this could be a few things wiring, lose connection within the box or elsewhere, a heavy user on the circuit. If you have these problems I would encourage you to get an electrician to check your electrical system and the load on it.

[doctorgonzo]

Originally posted by Paul Victorey Well, in some cases, you can't add the rated watts for devices, if the devices contain reactive loads. Watts are, by definition, the real component of the power, but there is the reactive power, too, if there is a reactive load.

True, but that is getting a bit complicated, and I didn't really want to get into that. Adding up the rated wattages will give you a ballpark figure, not an exact one, and I think the point is to see how close you are. If the rated wattage of the appliances you want to use total 900, I think you would be okay. If they total 1700, then I wouldn't risk it, because of the other factors that are ignored.

I am pretty sure breakers trip when the RMS current is exceeded, not peak current. Otherwise they would be tripping whenever you started large motors.

[piasabird]

My P4 1.8 Gig IBM Alta Vista has a 180 Watt Power Supply. As a note on rating of power supplies the rating of the power supply is not the average consumption of the item running. The reason for this is that On start up your computer will run all of the devices hooked up to check them. Then many items go into a sleep mode, like the CDROM and the Floppy and sometimes the Harddrive. Sometimes it is the steady supply of the 5 volt lines to the video cards and the low voltage supply to the CPU that is so critical to be supplied at a specific and steady rate of a specific amount of Amps that is important for the computer. The computer does not really need 300 watts of power, It converts it all to DC anyway.

To understand this a little better, take a fan in a furnace. The Rating in Watts it needs to run has to be 2 times the number of watts it runs at. The reason is at startup it pulls twice the watts. Some devices are like this and some are not. So if the power goes out and comes back on there is a huge stress on your power consumption.

Even if you leave a monitor on all the time, they usually have a sleep mode they go into where the actual pictrue tube or whatever shuts down. Still it is safer to turn off a computer if no one is going to be using it for an extended period of time. I have seen monitors start smoking in a computer lab when they get old and wore out! Also the fans on the computer can go out causing the CPU to heat up and possibly cause a fire. I was using a monitor program a while back and noticed even with fans, the temperature inside the computer case was over 90 Deg F. I prefer to shut my computer down and turn the monitor off.

There are lots of interesting articles on Power and wiring at the HOMEPOWER website. A site dedicated to Solar Power and power generation and usage. Have fun learning new concepts.

[piasabird]

You lose power if the wiring is too long in length or the wires are not of a sufficient gauge. This is the primary reason we use AC Power. AC Power is also easier to convert to different Voltages then DC.

[Sphegdave]

While we are on the topic, I was wondering what would be a good gauge wire for my room I am getting built. I am planning to be running many computers (not a server farm though ), a souround sound system, a tv, a couple of large 20 inch monitors, and maybe some colored lights. I also have an electric heater and AC on a separate 220V circuit.

[KronoLeginaire]

Originally posted by Charliey How many total breakers are in your breaker box? are there only one for each floor plus the stove/furnace/fridge?

We have a gas stove though. There are 15 breakers(5 dual) in total + the main.

1 for the 1st floor
1 for the 2nd floor & Attic
1 for the Hot Water Heater (dual)
1 for the furnace
1 for the washer & basement light
1 for a outlet int he basement
1 for the dryer(dual)
1 for the range(dual)

The fridge gets no privacy on the electic grid , lol.

[KronoLeginaire]

Originally posted by Sphegdave While we are on the topic, I was wondering what would be a good gauge wire for my room I am getting built. I am planning to be running many computers (not a server farm though ), a souround sound system, a tv, a couple of large 20 inch monitors, and maybe some colored lights. I also have an electric heater and AC on a separate 220V circuit.

No. No. Send some of that equipment over to me for an inspection first.

[jamesrpm]

Originally posted by Sphegdave While we are on the topic, I was wondering what would be a good gauge wire for my room I am getting built. I am planning to be running many computers (not a server farm though ), a souround sound system, a tv, a couple of large 20 inch monitors, and maybe some colored lights. I also have an electric heater and AC on a separate 220V circuit.

You're limited to a maximum of #12 gauge wire for normal residential outlets ,but not the number of circuits . If I was running all that equipment I'd have 3 if not 4 circuits to the room . Not just for the load though but to keep the power clean from one item to another.