Power (electricity) Issues and load.

mast3r

mast3r

mast3r

Soldato
Joined
28 Jan 2007
Posts
2,558
Location
Wilmslow, Cheshire
Hello all!

I wonder if anyone can help me out a little...

Each year i host a LAN Party for my clan and gamer friends, i hire a local Community hall for 4 days, usually have around 25 people there and 18PCs.

The problem is, power trips randomly and each time we have to turn the computers on one by one until we find which PC it is that causes the power to trip, sometimes we can just turn that one on first and we are good to go, the device which causes the power to trip can change from PC, Monitor, Charge or even a Switch.

The hall is old and the electrics must be old too, however when we get everyone online and working we can be good for an hour or a day and suddenly... DARKNESS, we have to flick on the power from the distribution board for the sockets.
We turn off anything that inst needed.

last year i took some massive UPS's which i think gave us some extra support.

Is there anything i can do to avoid these power trips, are they caused due to the amount of load?

Would more UPS's work?
these are Liebert GX range they keep 4 1000Watt quad machines running for about 30 mins.

Thanks All.
 
Most modern consumer units have a max draw of ~100 amps. Calculate the load for 20 pcs and the rest of your equipment and see what the total load is.
 
Sounds like the buildings electrics simply cannot cope with that amount of power draw. Im not sure if UPS would help tbh. Are there any buildings next door you could take power from?

If not, the safest way unfortunatly will be to reduce the participants or find a better venue....
 
Ahh as i thought, the only option is more power from a different supply?
We have no other building near by that would be willing to share power :(

I was kind of thinking that using a UPS to feed the Computers will reduce the fluctuating load from the mains and sort of "Cushion" the draw?.
The venue we have is absolutely perfect for us bar the power issue.

I will have a look into moving venue.
 
Is it the main distribution board? Or one of the ring switches? If its the rings, then using different ones would help. If you can find which is which!
 
its the main Distribution Board.
Would it be worth looking to see if i can increase the Fuse or load cut out ?
 
Using a UPS will make things slightly worse as it will consume a few watts itself especially if it's charging its battery. Though of course you'll get the benefit of your PC not switching off as soon as the power goes out!
 
Is there an RCD in the consumer unit? computers leak naturally to earth as they use the case for neutral and earth, usually a couple miliamps. 18 odd computers could easily trip a 30 miliamp RCD.
 
Is it the whole board that trips out or just a certain circuit? Depending on the install you may have an RCD protecting the whole board rather than an RCBO on individual circuits - as you would in a modern install. If its a community centre I would have thought someone would have retro-fitted some sort of earth leakage device on the board (most likely a small box to one side of the board).

If you do have an RCD on the board this is tricky to fault find, unless you know someone with a Part P tester. The RCD is looking for 'earth leakage' which is basically the difference between Live and Neutral. If its really old wiring, something a simple as someone walking over a floorboard with a cable underneath could cause it to trip if the cable is 'nipped', hence leakage to earth - as could moisture/damp with split cable sheathing etc.

If all the sockets are supplied from one ring main (one circuit) it could be that you are overloading the device on the board. This could be the case depending on the amount of gear everyone brings. although this would only trip your one circuit - lights etc would remain on.

Single phase supply from board, (probable supply device) 32A = roughly 400W per person, based on 18 PC's

I'm afraid UPS's won't be of much help if its an overload problem as they will increase the load, albeit minimally due to charging current for the batteries.

You could buy a cheap clamp meter (with 'max' reading facility) next time you go, go find the DB and the circuit in question and put the clamp meter on and start firing the machines up, if the breaker trips and you exceed the rating - problem solved!
 
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I've run several lan parties with the same problem, when it gets to the 15 - 20 pc mark the power tripps randomly.

Youll probably find that on the main cusumer unit theres a rdc with a 30ma trip on it, this is your problem, on the lan i run, i've had to bypass the 30ma trip for the larger 100ma one, this has allowed me to use upto 40 machines so far. I would not recommend doing this yourself however as we had to bypass and hardwire the buzzbars, which is not exactly safe.

Now im running a lan this weekend with about 50 people, and I decided to bite the bullet and build a purpose build power distro system, i did however have to put in a 63a single phase socket in the building. the power distro however will now provide 300ma break with each 16a socket seperatly covered by 16a 30ma rcbo's.

I've had quite a bit of experience in fiddling so if you want to know anything feel free to ask and ill try and assist :)
 
the problem is that on any RCD protected circuit you are not supposed to have an earth leakage greater than a quarter value of the rated RCD protection i.e. 30mA/4 gives 7.5mA.
Now a pc power supply has as rough figure (and to be honest a bit on the high side) of 1mA Earth Leakage, so in theory if you get 8-10 of these on a circuit you will start to get nuisance tripping. If you start going past 10mA's on any one circuit you should then provide a high integrity earth or dual earth return path.

Or as a quick shortcut just replace the RCD/RCBO with an MCB(cost around a tenner) and voila nuisance tripping gone, but i must point out this does not meet with the latest edition of BS7671!
 
As everything is tripping, I'd say it's got an over all RCD. (possible TT system)

Not a lot you can do tbh, As it isn't your building. Does the thing that trips have a little button on it? (press to trip)
 
He could link the incoming terminal directly onto the busbar if it has a main RCD incomer, naughty but it would work plus he would still get fault and overload protection from the MCB ;)
 
http://www.hss.com/index.php?g=41360&t=zoom

To obtain the true useable
kW output, you need to multiply the kVA by a
power factor of 0.8.
Power Output Capacity
240V power output. 22kVA continuous.
240V (when taken from the 415V 3 phases) power
output. 60kVA continuous (split 20/20/20).

22kVA x0.8 = 17.6Kw, Gah, not enough
You'll have to split the 3 phase outputs down to 3 sets of outputs
60KVA x0.8 = 48Kw. More than double what you need now, so you can still have the lights on and keep the toaster and kettle hot. :D

PSU output x Number of PC's
800w x 25 = 20,000w or 20Kw :D
 
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Stanners said:
He could link the incoming terminal directly onto the busbar if it has a main RCD incomer, naughty but it would work plus he would still get fault and overload protection from the MCB ;)
Click to expand...

Don't do this, It's a stupid idea :)

This isn't his building people! He won't be changing any RCD's or playing with the installation at all.

If it's a over all RCD (likely) how do you suppose he is going to change said RCD? It's unlikely to have an isolator before the RCD so short of cutting the seal on the main fuse and pulling that I'm not sure what you lot are on about.

You are bang out of luck I'm afraid, Live with it or choose a different venue.
 
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