A lesson about resistance learned the hard way

[nevermind1534]

teh,, I'm getting dual 20A sockets in my room. I dun like running all my current stuff on a 15...but it has to do for now.

Why...again...do you have 16 computers?

LAN party

16 gaming computers (some laptops, however), most with huge monitors. Actually, there were 17, or 18, if you count the one hooked up to the TV for spectating.

 

[Thelis]

 

[nevermind1534]

lmao

That was after a good 8 hours.

 

[dudelewis1]

lmfao thelis, u pwns

 

[J03]

Thanks for your posts, berry120.

I have been zapped by 120V three times. One can never been careful enough.




With 16 computers, yes, you are a little limited.

There were 10 in that room, 6 in the next room




Yeah, but the computers, unless you have an overdraw (bad or insufficient PSU) are going to use less than the rated value.

I find it easier to just take the watts and just divide by 120.

Or 230 if your in the UK.

 

[vampist]

There should be a rating on the back of your power supply. Just use this calculator to convert watts to amps.

http://www.jobsite-generators.com/power_calculators.html

Eh watts to amps is an easy one. Watts / volts = amps

 

[root]

But wouldn't you have to run the cords all over the house to really have any effect?
I mean yes the lead cords and power strips are good but plugging them all into different outlets.. I can see SORT of working.. But usually the circuit breaker is set up for rooms. Thus the reason why you would have to run them all over the house.


EDIT: Yes plugging them into different outlets would release pressure on the wires leading to the outlets. But they all lead to the same place.. Usually to one wire that leads to the breaker.. Right?

that'd depend what the specific wiring in your house was like.
certainly in the UK it's fairly standard to have a 60amp breaker just marked sockets, and that'll be the breaker for all the sockets in the house.

besides which, fundamentally, breakers don't really care about the current draw, (fuses care about current draw) breakers care about instantaneous draw, which is why they can be reset easily, so if they turned all the computers on at once, the inrush current would be enough to trip the breaker...
you'd have to check your fuse board to see which kind you have, (usually a combination of both, but not in the same place, (RCD (residual current device) and resettable Fuse)

As long as you're well within all these limits (and any others that might exist, I'm not saying that's an exhaustive list!) then you're fine. So if your upstairs ring main has a limit of 32A and you're drawing 25A worth of stuff, you'd need to run it from 2 different plug sockets that weren't part of the same double socket, but you could still use the same ring main quite safely. If you had 35A worth of stuff for whatever reason, it's a different story and yes you would need to start running cables all over the house!

ahhh you assume that there is a ring main, but what if there is not? what if there is just an extension sometimes sockets are wired into the wall not on a ring main, but sockets are just wired in parallel going down a run effectively daisy chaining them together.

I know that sounds melodramatic, but electricity can be lethal even on a domestic level if people mess around with it. I for one would always advise that when you're not sure over something, check it with the relevant calculations, double check, and if you're still not sure get someone who is! This isn't meant as a go at anyone, I'm genuinally glad no-one was hurt and that you learnt your lesson I just hope this goes down as a reminder to everyone that reads it!

indeed, funnily enough 50Hz (mains frequency) is also the most damaging frequency that electricity could be when passing through your body. (as in a set current at 50Hz will cause more internal organ damage than the same current at 100Hz.)

I have been zapped by 120V three times. One can never been careful enough.

never been zapped with 120 cause we have 240 over here,

I find it easier to just take the watts and just divide by 120.

indeed, power = volts*amps
amps = power/volts
volts = power/amps it's another one of Ohms calculations
(in the UK divide by 240).

teh,, I'm getting dual 20A sockets in my room. I dun like running all my current stuff on a 15...but it has to do for now.

I assume that you're getting the wiring upgraded as well in the walls?
Anyone can put a cooker socket in their bedroom, that doesn't mean that they've got the power to run a cooker.

 

[berry120]

Dude you really seem to know your electricity, this is twice now you have answered on the same subject.

Thank you for the information!
By any chance would you happen to know the average amount of volts/amps/watts a average computer pulls?

No worries, I'm no electrician but I need to know a fair amount for all the tech (sound / lighting) work I do. When you're dealing with a show running off a generator spitting out 125A 3 phase and almost running it to its limit you really need to make sure all your phases are balanced, you're not pulling too much at any one time on any breaker etc. otherwise things will go very wrong!

Volts will always stay constant, you get whatever the supply gives (so if you see something rated 230V, it's getting 230V.) Current on the other hand is kind of "taken as it's needed", so if you've got a 13A supply and you're drawing 5A, that's what you're using. It's not going to do any damage if you give it a 2 million amp supply, it'll just be a huge waste of a supply!

Actual power isn't given just by V*A, but we'll assume it is here (it's close enough to it!)

As for how many watts an average computer uses - well it varies drastically from about 5 to 500+, but take your "average" computer and it'll probs be around the 200 mark. Though if you've got a room full of i7's and SLIed graphics cards, that figure will need to be raised accordingly... otherwise you might see situations like the above again!

 

[Grantofhell]

I assume that you're getting the wiring upgraded as well in the walls?
Anyone can put a cooker socket in their bedroom, that doesn't mean that they've got the power to run a cooker.

Nay, We build houses and are currently building our own. I've specified what I wanted and we settled on it. We'd love to to our own electrical work, but we don't have the certification to get an inspection pass. The wiring is already in my new room, as is the drywall, but we need the electrician to put in the rest of the breakers.

 

[ZackDawley]

thats why every house setup for lan parties has 6 different circuits in the lan party room