Drawing large amounts of power from an outlet safely?

[athenian200]

I'm somewhat curious about how much power I can actually draw safely through one standard outlet with two plugs.

The thing is, I'm going to need to plug in several different devices into this one outlet using power strips in order to make my setup work, and I've heard people say power strips aren't really safe to use because they allow drawing more current than the wiring was designed to provide, or will just keep tripping the circuit breaker.

I'm wondering if there's any sort of device I could buy that's designed to get around that limitation. Here's what I'm going to be plugging into a standard wall outlet.

1. 24" Sony WEGA CRT Television set.
2. 4-port Component input Extender.
3. VCR
4. DVD player
5. Nintendo Wii
6. Gamecube
7. Nintendo 64
8. Super NES
9. Sony Playstation 2
10. Sega Master System

The thing is, most power strips that I see only have 8 ports, so normally I would need to run two from the outlet, which is the main thing I've been advised against doing. The other major concern I have is that I'm not sure if the entire room is on the same circuit.

The reason is that I already have two PCs with 650W power supplies, two LCD monitors that draw around 30W each, an alarm clock, a router, a UPS backup system, two sets of computer speakers, a lamp with an LED lightbulb drawing about 8W, and a large room fan that runs constantly. They're not hooked up to the same outlet, but they may well be on the same circuit.

Is there anything I can do to make sure that the wiring can handle this, it doesn't trip any circuit breakers, and that the whole setup is perfectly safe? Would having another UPS for it help? Do I need a special PDU instead of a normal power strip? What's the right way to deal with these power needs?

 

[Track Drew]

Assuming you're in the US and this is a 15A, 120V circuit.

Max sustained load should be 80% capacity or 12A. This comes out to 1440 watts.

You have the potential to go over that, but that's assuming both power supplies are drawing 650W, which isn't likely happening, its probably half that tops.

As far as your list goes, only the CRT TV will put a large load on the circuit. Even then its likely far under 200W. The game systems all draw less then 50W each (most less then 25), and chances are you only power one game system on at a time too.

Buy one of these: http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU

Use it to determine just how much current your devices actually draw, it won't be exactly accurate, but it will be close enough.

Instead of guessing if the room outlets are on the same circuit, why not just figure it out. Sequentially switch off a breaker, check to see if any outlets lost power, switch breaker back on, try next breaker, repeat, until you have at least one outlet loose power. If any others stay on, then they aren't on the same circuit.

Another UPS won't help anything except give you more outlets, which can also be accomplished equally well by a power strip. As far as safety and two power strips connected to one outlet, which is safer?

A) One power strip with 8 space heaters connected to it
or
B) Two power strips with 16 90s era video game systems connected to it.

Lastly, is this someone else's house (like your parents)? If so, its usually just better to follow what they tell you to do - unless you all want to sit down and educate yourselves about electricity.

 

[plugwash]

Note: the post below assumes you are in north america because of your use of US terminology. If you are elsewhere please say so so we can give you more relavent advice.

I've heard people say power strips aren't really safe to use because they allow drawing more current than the wiring was designed to provide, or will just keep tripping the circuit breaker.

What really matters in most cases is the total load, not how you connect it.

Providing the wiring was installed correctly the breaker should trip before the wiring is dangerously overloaded.

I'm wondering if there's any sort of device I could buy that's designed to get around that limitation.

Not really, the max load of a circuit is the max load of a circuit. The only way to increase that is to make changes to the fixed wiring.

They're not hooked up to the same outlet, but they may well be on the same circuit.

If you don't know what stuff (note that lights and possiblly other fixed equipment may share circuits with sockets) is on what circuit you should really find out. It's easy enough to turn the breakers off one at a time and look what stops working.

Is there anything I can do to make sure that the wiring can handle this, it doesn't trip any circuit breakers, and that the whole setup is perfectly safe?

You really need to know both the actual load of the devices you are using (get a device to measure it, going by nameplate ratings will give you a gross overestimate) and the rating of the circuits that are supplying them. Once you know that you can calculate if the supply is adequate).

Would having another UPS for it help?

No a UPS will likely make matters worse, especially when it tries to recharge after a power failure.

Do I need a special PDU instead of a normal power strip?

It won't make any difference to whether or not you are overloading the fixed wiring.

What's the right way to deal with these power needs?

If you determine your power needs are higher than your current fixed wiring supports then the only way to fix that is to change the fixed wiring. There are a few possibilities.

1: If the circuit is wired with sufficiently thick cable (check your local wiring codes) and has a 16A breaker it may be possible to increase it to 20A. However you MUST NOT increase a breaker size without first checking that the wiring is adequate throughout the circuit.
2: if there are other circuits nearby that are not near their load limit it may be possible to extend them to the area where the high demand is.
3: it may be possible to convert the circuit to 240V. This would double the circuit capacity with no extra wiring. The problem is you would then need a special UPS with 240V input but 120V output. APC apparently make such a thing but they apparently only distribute it in brazil
4: the last resort of course is to add a new circuit from scratch.

 

[athenian200]

Yes, I am in the US, and it does appear to be a 15 amp breaker. I looked at the circuit breaker box, and most of the breakers in it ARE actually 20A, but the three that go to the back of the house (one per room) are 15A.

I have to say, I'm really unhappy about what I'm hearing, that the wiring limit is the wiring limit, and there's just no easy way to draw more power out of it. They really are harsh on those limits, and it is a bit frustrating that there's not some kind of workaround like there is for most other things. 1440W Max sounds like a bit less than I would prefer to settle for. I mean, there are lots of things I'd like to add to my room that might use a little bit of power over time, and I find it really frustrating that the circuit would barely support both of my computers at full load.

I calculated out my power needs, and I apparently need right at 1900W to be absolutely safe. I probably won't draw that much all the time, but that is the peak, and I don't want to cut it that close.

EDIT: Well, I was right on the other stuff, but I overestimated the computers slightly. Apparently there's no way either of them would draw more than 500W even at peak load. They drew more like 450-470W each at full load, and it was tough to get them to use that much. That means the estimate can be brought back down to... about 1900W max. I still need more juice, but not that much more. I'm still about 400W-500W over what I need, though. That CRT is what's killing me, I know, but I really want to use it...

The idea of installing that 20 amp breaker is looking REALLY tempting, because it would provide more power than I'd ever really need, especially since most other rooms in the house seem to have one aside from the back three. I guess I'm going to be doing research into how to measure the wiring gauge/quality to see if I can safely replace the 15 amp breaker, because that seems like the easiest solution...

If I can't, I guess I'll be trying to get an electrician to install more circuits. What a pain, but if I have to do it, better now than later.

If they were newer game consoles, I could probably just get rid of the CRT and hook up an LCD, but these old games look awful on an LCD and would have too much input lag...

 

[Tsumi]

It has everything to do with the physical properties of a wire. Most household circuits will never need more than ~1500 watts on a circuit, and the cheapest (read, thinnest) wires are chosen for that purpose. Thicker wires are needed for higher draws because thicker wires reduce the resistance of the wire, and thus the heat generated by the current moving through the wire. Draw too high of a current, and you risk the wire catching on fire.

For some things, there are shortcuts. For this, there are no workarounds because it has everything to do with the physical properties of a wire and average construction standards.

What exactly are you powering? Chances are you're grossly overestimating your needs.

 

[athenian200]

What exactly are you powering? Chances are you're grossly overestimating your needs.

The big items are two computers that can potentially draw up to 500W each (right now they probably only draw 450, but capacitor aging or adding a second video card to one of them could change that) and a 24" CRT television, which I've been told draws up to 200W by itself. That gets me up to 1200W already. By the time you add in my lamp, computer speakers, monitors, alarm clock, router, a large fan that I run all the time, and UPS backup system... I probably have around 1300W used when I turn that TV on.

Now, what I want to ADD to this configuration... are the things on my list. 8 video game consoles, a 4-port component input connector that requires its own power supply, a DVD player, and a VCR. And to be honest, sometimes I need shorter bursts of more power... I have a lamp with 2 60-watt bulbs that I rarely turn on unless I'm looking for something and need more light. I have chargers that I plug in when I need to charge something. And I might eventually want one of those wall-mounted digital clocks that tells you the time in several parts of the world, so I can tell that at a glance. Or I might need to plugin a laptop, or maybe even an older computer that draws another 200W that I use occasionally to read floppies.

I just don't feel like 1440W is enough headroom for everything that I want to do in here... possibly I could make it just barely work, but I'd rather not have to worry every time I turn something on about whether it will trip the circuit breaker, or whether I need to turn something else off first. I'd feel a lot better about setting this up if I had a higher threshold to work with. The way I see it, it's better to have it and not need it, than to need it and not have it.

The kind of workaround I was thinking of, though... would be some sort of device that can use battery power to complement wall power, so that during periods of high load, some of the burden is taken off of the wall outlet. Sort of like the opposite of a UPS... instead of providing backup power for failures, it prevents failures by adding power from another source into the stream headed for the device BEFORE the threshold is exceeded and the circuit breaker trips. I guess they don't have anything like that, though. Basically, something that's designed to take some of the burden off of the main power.

 

[Tsumi]

No, there is nothing that can really provide what you're looking for. Too small of a market for anything like that. Besides, the cost of batteries and a an electrical regulator that can provide that probably outweighs the cost of simply redoing the wiring.

 

[larrymoencurly]

15A @ 120V = 1800W. I'd try to stay below 1200W.

You should test the outlet by running a hair dryer full blast (that's about 1500W) from it while measuring the voltage (Kill-A-Watt is the safest way). I used to live in a house where 3-4 outlets would really bog down becuase of poor wiring connections, in one case from 121V down to 90V. In every case the problem was a loose push-in terminal.

 

[bob4432]

why not get an emulator for the older video game console and run it off one of the computers? also figure out if they are on the same circuit - ma condo is a bit interesting how the circuits are split between rooms...

 

[RazorWind]

Have you considered turning off one of the computers?

 

[athenian200]

No, there is nothing that can really provide what you're looking for. Too small of a market for anything like that. Besides, the cost of batteries and a an electrical regulator that can provide that probably outweighs the cost of simply redoing the wiring.

Yeah, so I guess I'm going to upgrade the wiring. I'm already trying to find someone who knows this stuff... may end up having to hire someone, but I have friends who've worked with general contractors and have experience wiring homes up when building them. I know that sometimes they let these guys do the wiring, and only pay the electrician to inspect it (in order to cut costs).

15A @ 120V = 1800W. I'd try to stay below 1200W.

You should test the outlet by running a hair dryer full blast (that's about 1500W) from it while measuring the voltage (Kill-A-Watt is the safest way). I used to live in a house where 3-4 outlets would really bog down becuase of poor wiring connections, in one case from 121V down to 90V. In every case the problem was a loose push-in terminal.

I'll definitely make sure I don't have any issues like that before this is all said and done. I'm pretty careful/particular about things like that.

1200W isn't going to be enough at all, just shows that I REALLY need to upgrade the wiring.

why not get an emulator for the older video game console and run it off one of the computers? also figure out if they are on the same circuit - ma condo is a bit interesting how the circuits are split between rooms...

Well, for one thing they're technically illegal, ISPs are doing more filtering, and there have been a lot of crackdowns lately. Plus, I'm not a minor anymore... so... yeah.

For another, a lot of these games don't work well on an LCD television, let alone an LCD monitor. That's part of why I'm having these issues... I need enough power for an older CRT television.

Have you considered turning off one of the computers?

One of the computers acts as a server most of the time, and thus I don't want it turned off. The other one is the computer I use everyday, and thus I would have to turn off my computer every time I wanted to play a game. And to be fair, I'm the type of person who would eventually forget to do that, and trip the circuit breaker frequently.

Thus, I'd rather deal with the issue now so that I don't have headaches later with having to turn off my computer every time I want to play a game.

 

[BTU_Natas]

Ehm, why dont you just move the server to another room then? Solves all the problems.

 

[ccityinstaller]

15A @ 120V = 1800W. I'd try to stay below 1200W.

You should test the outlet by running a hair dryer full blast (that's about 1500W) from it while measuring the voltage (Kill-A-Watt is the safest way). I used to live in a house where 3-4 outlets would really bog down becuase of poor wiring connections, in one case from 121V down to 90V. In every case the problem was a loose push-in terminal.

I worked for my cousin's EE firm for 2 years, specializing in typical unit plans (read, electrical blueprints) for both commercial and residential use. As long as the house was built fairly recently, say the 80's or newer, you will be fine drawing up to ~1650W on a single 15A circuit..

Keep in mind that is the max load value, and doesn't accord for any surge loads (like when you first power up a vacuum cleaner, or a high powered hair dryer)..I would invest $25 bucks in a Kil-o-Watt meter and check what you max loads are when first powering things up, and when everything is running.

 

[RazorWind]

Ehm, why dont you just move the server to another room then? Solves all the problems.

This. Or go to low power hardware. I refuse to believe you need a 650 watt server if you're living in a single room. Obviously not cheap, but possibly less expensive than installing another circuit in a house you apparently don't own.

It's probably worth considering though, that that server is spending most of its time idling. Idle power for a typical PC is not 650 watts, but realistically more like 150. You should plug in a Kill-a-watt to check on what you're actually using. Consider doing things like turning off the hard disks when they're idle for 20+ minutes, and using lower power hardware, like the onboard graphics, if it's a relatively recent Intel CPU.

Also, consider using the sleep feature on the PC. That will reduce its consumption dramatically, if you're not actually using it.

Finally, you're not likely to use all eight game consoles at once. Employ a modicum of sense, and I'd be willing to bet you won't have a problem anyway.

 

[DraginDime]

I have all kinds of crap plugged up in my pc room on one 15A breaker, and the only thing that ever causes me any issues is when my wife runs her ceramic heater on HI while we are gaming, and it only kicks the breaker 1 out of every 50 times she uses it that way. I never had the issue before I bought her that heater, and I've ran that much crap in there for at least 6 years. Everything is spread over 4 different outlets, but they are all ran on the same breaker.

Here's a list
Xbox 360 / Xbox Classic / My PC (see sig) / My G19 Keyboard / Wifes PC (Q8400 OC'd, 6950 2GB, 8GB Ram, 2 HDDs, 700w PSU) / All in One printer / Lenovo L420 Thinkpad Charger / 42" Sharp LCD tv-monitor / 32" Sony LCD tv-monitor / 24" Asus LCD / Modem w/wireless router / Desk lamp (1 bulb) / A small ceramic heater / Humidifier / old digital alarm clock / telephone / Window A/C unit (15000 btu I think? was the biggest 110v I could find) / 2 sets of pc speakers-sub-amp

The A/C, ceramic heater, humidifier aren't used much at all, but are always plugged in. We turn off the monitors at night, but that's about it.

 

[TESLA]

Power supplies draw power on demand. As others have said, there is no way that you will be drawing anywhere near 1,900W under normal use. So unless something about your intended use is exceptional, you should not have any problems on a 15A line.

Most homes in the US have 15A breakers everywhere except perhaps the kitchen, etc.. Look at what some people are running in the "Show Us Your Workstation" thread. Many setups are comparable to your own.

Also, if you are talking one server and one general use PC, 450W+ for server duty in a home environment is a lot. What is your server providing?

If you still wish to modify the circuit, check local code first. This not only includes wiring code but also on who can do the install. Some states will require a licensed and insured individual to perform any work. Keep in mind that even if everything is technically safe, with all wiring to code, the little things can still cause insurance to deny a claim (even if a claim is not electrical related), a future house sale to fall through, and/or etc..

As for a general guideline regarding 20A circuits under the NEC, to up your 15A breaker to a 20A breaker you will need at least 12-2 line. 14AWG is for 15A, and 12AWG is for 20A. If you already have at least 12-2 line run, and you have more than one 15A receptacle (or at least one 20A receptacle) on the circuit, all that should be required is a change in the breaker so long as your panel has spare capacity.

 

[bob4432]

i too am curious about the 450W home server - what is it? you should be able to get that under 100W no problem - take out the gpu and use remote desktop to get into it - works excellent.

even w/ an skt939 opteron165 @ 4 HDD my home server that serves up audio/video/http/ftp/print i am only pulling 95W according to the UPS.

have you used a kill-a-watt to see how much the consoles take - i thought the roms were not an issue after x amount of years, but i forgot, that is more patent stuff. i just don't see the consoles taking that much power, but would like to be educated.

 

[staticlag]

It really depends on YOUR house and YOUR wiring.

Everything said here is theoretical.

I mean there is no guarantee that your wiring was done correctly or up to code.

Chances are if you have a house older than 30 yrs old then you will have inadequate wiring in the walls to support that much draw from a standard room wall outlet.

Your best bet is call a licensed electrician and have them evaluate your setup and possibly install a 220v outlet for you.