Building a 4 PC Lan. How do I cool the cabinet and keep it silent?

[Smoblikat]

Depending on your price range you could build them into a watercooling loop. If you dont have the dough to make a real one, get one antec khuler 620 per GPU and send me a PM............I have a solution.

 

[natto fire]

The loads of GPUs are so dynamic that it will be tricky to size your cooling and UPS requirements accordingly, but you can probably skimp a bit on UPS, unless you are planning on trying to run the graphics cards full tilt after a power outage. Not sure what cards you are using, but my main system with an inefficient overclocked 1090t, HD5770, 5 120mm fans, bronze 650w PSU only pulls ~280 watts from the wall, fully loaded.

As I'm sure you have noticed, UPS are rated in volt-amps, which is only the apparent power. You will need to know the power factor of your PSU to go back and forth from watts and VA. I would personally set things up so that the computers immediately begin shutting down once the UPS switches to battery, which should allow you to "under size" your UPS a bit instead of having to worry about full load power draw.

Is your 30a 220 circuit on a double pole breaker? You will definitely want to switch to 2 single poles if that is the case, and I'm assuming you are on #10 wire? Depending on the power factor of your PSU, you should actually be fine on a 15A up to a 1000w PSU. Keep in mind that electric heaters are 1500w, which is only 12.5 amps, (meets the 80% cushion of much more common 15 amp circuits in many homes)

 

[007ELmO]

Hi,

The 30A 220 is on a double pole, with a single #10. If I break it, can I get two 30A 120V out of it, or two 15A 120V?

I am not too worried about the UPS with power going out, as I'm only going to use the setup once a month probably - I'm more worried that a single 15A breaker is not going to provide enough wattage for 4 PCs.

Is that concern blown out of proportion considering you're only pulling 300W? I'd pull about 1200 if they're all under load in that case.

Last night I was considering scrapping the idea and just doing 2 PCs (with maybe a little more power). That would scrap my LAN party ideas for the most part then.

ELmO

 

[natto fire]

You can pull 30 amps from each leg of the double pole breaker, but it is against code to install a single receptacle that has lower rating than the breaker it is connected to. A 15 amp receptacle would melt well before the breaker tripped if you were overloading it. Of course, with most shorts/faults, the amperage jumps way past 30 and will still trip the breaker, you would just have to be mindful of what is plugged into the single receptacle.

When you say it has one #10, do you mean only one leg is connected to the breaker and you get 220v from that one wire to ground? If so you are wired to a rare delta transformer, but I don't think they put houses on those, so I am probably misunderstanding.

Some double pole breakers have an internal common trip and cannot be split, but most are external and can be removed giving you two independent circuits of the ampacity shown on the breaker.

If you have space in your panel, you might be better off putting in a 20a breaker and getting a 20a receptacle or two just to make sure you are doing it to code and still have a dedicated circuit for the computers.

It is always a good idea to overbuild electrical systems, but there is a point when you are wasting time and money overdoing it. Your house is probably not large enough to worry too much about voltage drop from wire lengths and multiple junctions.

 

[007ELmO]

I will take a picture if necessary, but I installed a sub panel for 240V underfloor heating. There are 4 circuits on there, 1 15A, and three 30A double poles. I'm using 2 of the 30A double pole 240V for heating and the third is unused. It has a single 10GA wire.

I want to take that double pole and break it into two 120V 15A. I actualy have to, or I can't wire the other part of the basement correctly. The basement will be on 5 breakers, and my panel is full. Two theater rooms' equipment, hallway lighting, lounge room (with another projector and kitchen), and the PC area. I'm not sure yet as the electrician didn't get back to me, but I hope to break hte 240V 30A double pole into 120V 15A (two), with one dedicated to the PCs and 4 LCD monitors.

Thanks for getting back to me!

 

[jaedaliu]

I will take a picture if necessary, but I installed a sub panel for 240V underfloor heating. There are 4 circuits on there, 1 15A, and three 30A double poles. I'm using 2 of the 30A double pole 240V for heating and the third is unused. It has a single 10GA wire.

I want to take that double pole and break it into two 120V 15A. I actualy have to, or I can't wire the other part of the basement correctly. The basement will be on 5 breakers, and my panel is full. Two theater rooms' equipment, hallway lighting, lounge room (with another projector and kitchen), and the PC area. I'm not sure yet as the electrician didn't get back to me, but I hope to break hte 240V 30A double pole into 120V 15A (two), with one dedicated to the PCs and 4 LCD monitors.

Thanks for getting back to me!

I like that you have an electrician doing the work. It's not necessary, but sometimes it's nice to have a professional.

you should have 3 phase power, which is 220 between any 2 power leads, and 110 between a power lead and neutral. I'm not entirely sure how it'll hook up for balanced power, but you have plenty available for 110v to power the computers. At the simplest, you could give each wall outlet its own circuit breaker, and plug 2 computers into each wall outlet panel. This is standard wiring for window air conditioners, so your electrician should have no problem understanding what you're trying to do. he might be a little confused with why you would want to put them next to each other, but he'll do it for you.

 

[007ELmO]

The problem is I want to only use ONE of the 120V 15A breakers for all 4 PCs and monitors, because I'll need the other one for the kitchen/lounge projector area. if I take up both with the PC section I'll have no power left (hehe).

I'm pretty sure I will have to give the electrician another call, he works for NASA and does electrical work on the side, I doubt he cares about my projects that much (haha).

 

[Lonyo]

An i5 3470 plus GTX650Ti uses 150w when loaded with Intel Burn Test and Unigine with 1 SSD and 1 2.5" HDD, for reference.
Even if you add in a more powerful GPU, you're not really going to break 250w per machine under load.

 

[007ELmO]

Good!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[007ELmO]

Here you go Captain Howdy!

Can I take one of those 30A 240V pair, and turn it into two 15A 120V?

Thanks!
ELmO

 

[jaedaliu]

Here you go Captain Howdy!

Can I take one of those 30A 240V pair, and turn it into two 15A 120V?

Thanks!
ELmO

I think you would need a 110 subpanel, but yeah. one 30A 240V should get you four 15A 120V. I think. This is why you want to talk to your electrician. school knowledge about P = IV isn't the same as what's code and how to actually wire stuff so you don't burn down your house / kill yourself in the process.

 

[007ELmO]

I have no problems talking with an electrician, he's the one who installed that 240V panel for me, but he said I have no room left for expansion. I don't think he needs a separate 110 panel because you can see a 15A breaker exists in this same panel.

Although I've done wiring of stuff in rooms down there, but I will not touch a panel.

 

[007ELmO]

Update, I just had a certified electrician come over and verify I can take those 240V 30A and turn them into two 120V 20A.

Excellent! The 20A will easily be enough for 4 PCs wattage. I'm clear. He's going ot charge $50 to change out the breakers.

All I have to do is run two 12GA romex from near that location to where I want them. One 12GA is going to be just a single 20A outlet, the other will supply power to an equipment rack (PC, cable box, receiver, projector) - the kitchen area (compact fridge) - and lighting. Hopefully THAT can be handled by a single 20A!

Thanks,
ELmO

 

[007ELmO]

I ran 3-12GA lines, but nothing is hooked up into the breaker box yet. I'll use the 4th 10GA line that's hanging there and get it plugged into another breaker, so I should have 4 new 20A-120V breakers, which will breakdown as such:

1) Underfloor heating
2) 4 PCs and monitors
3) Lounge projector/kitchen area
4) Infinite baffle subwoofer area in main theater room

Cool! I'll continue to post pictures as progress moves, but it may be a little while (another month).

 

[007ELmO]

Hi everyone, if you're interested I moved my conversation for this build into another thread (linked in my signature, "Building out Home LAN (4 PCs). Thanks for the input so far.