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Thread: Time to rewire the lab
11-23-09, 08:15 PM #1
Time to rewire the lab
Well I got my first tripped breaker tonight and found out my lab is running on a 15amp non dedicated line. W00T W00T here's to hoping I don't destroy my gear before I have the money to rewire the place.
So right now its a 600W, a 550, and a 450 for the PSUs running. Will be adding more but I will not be able to do so till after the rewiring of this room. Planning on going overkill on this maybe 200 to 300amp fuse able disconnect with 40amp dedicated lines to outlets. Hopefully will have it done with in the next 6 months. Really trying to leave myself at no higher than 80% load on circuit.
11-24-09, 12:35 AM #2
Man... are you sure... maybe I just don't know what kind of wiring I've got. As far as I know, I'm running 4 C2Qs and 1 i7 on the same circuit... no drop outs yet. :cross fingers:
This is standard house wiring (as far as I'm aware) and I know I'm pulling a good 2k Watts at the wall... Easy.
Just curious... I've popped the breaker plugging in the vacuum a couple times... but I had a couple more rigs going in here at that time... pardon me if I'm rambling... doing a bunch of this... and some more... I'm workin' on HFM and I don't have to go to work tomorrow.... ...and another...
11-24-09, 03:46 AM #3
At one moment at my job we had some real power issues in a server room. I think we had the equivilant of 20 computers on 2 15 amp non dedicated circuits (run into the room with 100 foot extension cords) over an entire weekend.
Stupid lightning strike killed the transformer and 7 surge protectors which is why we had to bring in power from the other side of the building. That was a fun weekend. We were so tight on power that everything had to be brought up 1 at a time (couldn't just flip on the big red power strip button or the spike would instantly trip the breaker resulting in a 150 foot walk back and forth).
I swear it was exactly like in the Apollo 13 movie where they got the ammeter and they are counting up the amps and trying to make it work with the correct startup sequence.
. . . . . . .HELP!!!. . . . . . RAWR!!!
. . . . . . . . .\. . . . . . . . /
11-24-09, 06:15 AM #4
If you were running all PSs at max, which is almost impossible, you'd be drawing 13 amps. I'd guess your actual draw at the wall is closer to 1/2 the PS ratings. 30 amp circut is more than enough. No point putting in a fuseable disconnect if you size it larger than the house panel. THe fuses won't blow even if the wire in your lab melts.
11-24-09, 10:15 AM #5
A two circuit 20A breaker set up, is safer than having just one 40A service.
If there should be a short, the heat generated by 40Amps+ burst, is far greater than that generated by a short burst of 20A+.
11-24-09, 11:03 AM #6
11-24-09, 11:17 AM #7
Thank for the input but like I said I threw a breaker. Not that my rigs did its because this house has old wiring and the breaker that I'm on is not dedicated to just this room. We had to plug a space heater in because the pilot light on my heater won't stay lit(Its dropping to like 50ºF in the rest of the house. Doesn't matter how cold the lab gets just the rest of the house.). The extra juice pulled by the space heater is what tripped my breaker. Never the less even if I was only pulling 50% I want a fuse able disconnect in here so I can kill this entire room. Thor hates me and often sends bolts to fry my hardware. So yes as it maybe over kill I'm going to protect my farm room because over the last 10 years I've lost about 8k in gear due to lighting strikes. The last one being the worst the whole room felt charged for about 2 week. I'm still trying to sift through all the gear but so far about 80% doesn't work and to make matters worse we're talking about stuff that wasn't even hooked up stuff sitting in anti-static bags in boxes will not work now. So I feel that making this lab a dedicated circuit that can be completely cut off from the world is a great thing.
11-24-09, 11:54 AM #8
Ya, a space heater would do it for sure. From 300W to 1800W would certainly trip a breaker in my room but going for 200A line is definitely uber overkill! Heck, my 1800 sq. ft. house is all electric, including heating with a 200A main box from the hydro. I'd say route a 220V line from your main box and install a small secondary entrance box with 30A or 60A fuse or breaker in your lab and pull 120V power from that with regular 15A breakers , I prefer breakers as those large cylindrical fuses die over time.
As to your lightning issue, have you ever installed a lightning arrestor like that at your main box? Seems like the feeder lines from the power company are garbage.
11-24-09, 11:57 AM #9
Adak is spot on about 2 20 amp circuits being better than a 40 (I don't recall seeing a 40 amp 120v breaker) or a 30 for that matter. My point is that a "200 to 300 amp fuseable disconnect" won't actually provide any fuse protection at all for a 40 amp circut. THe #8 wire required for a 40 amp circuit will melt before a 200 amp fuse will blow.
Anyway it's a slow day on the forum, so everybody is going to give you all sorts of advice you may or may not need and may or may not want.
11-24-09, 12:09 PM #10
I'm pulling 1881 watts... which equates to 1881w / 120v = 15.675amps.
--- curious now, h goes to check the breaker box ---
All my breakers are listed as 20 or greater, which I must assume is the amp rating. So I think I'm good, I just don't need to push it much more.
I'm such a thread jacker... my apologies AF.
11-24-09, 01:11 PM #11
Oh BTW, I like the pair of 20A lines suggestion as you'd only need an extra length of #12AWG wire if your entrance has the space and power available. Many older homes have a 60A entrance or less. I don't know what the Op's future plans are on expansion but the two line option will certainly be good for a few more folding machines. It would be be less expensive too.
11-24-09, 01:57 PM #12
Thanks guys I did work as an electricians helper for a year or two(Like 8 - 12 years ago). However we only did industrial and commercial jobs. So yes most of my ideas are overkill for a house. However there are things that may happen that may lead me to needing more power in this room. I'd really like 2 racks in the closet with a chem hood vent w/temp regulators to pull all air over said º into attic out of house. Plus it would be super sweet to open the two windows in this room and just crank up the hood and the OCs in the middle of winter.
11-24-09, 04:19 PM #13
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make sure you sue outlets rated at whatever current you're planning on pulling. I bought a box of cheap 10 amp outlets to replace the old 70s ones in this house that had 10 layers of paint on them. There are higher current rated ones, but with the higher current came a higher price. Some builders would use the cheapest outlets they can get regardless of it's intended use.
If it was me, I'd run a 6 gauge 4 conductor bundle; 220, common and ground. Then a small service panel with a 30 amp entrance and 4 15 amp circuits throughout the room, 2 on each leg of the 220. that should give you 6,600 watts, enough for AC and space heaters, and all of your farm. Keep in mind that I'm not a pro and have no formal education regarding mains wiring.
as for the lightning, i recommend you look into halo grounding. the static bags help protect from ESD, but not from EMF inducing currrent on traces. When I worked at the computer place we would get a computer in almost every time it stormed good, the modem would die because phone lines act as a huge antenna picking up the magnetic wave the lightning produced, and conduct it directly to the modemStudent of Electronic Engineering as of September 20, 2010
11-24-09, 04:40 PM #14
I might not have been too far off with my suggestion of a separate box in the lab as you only want to do this once and according to your local code of course, that's info for others that might want to shave a few bucks off. Hey, as long as your main entrance supports what you need, then go for it!
You're closer to being an electrician than many of us are.
11-24-09, 04:41 PM #15
11-24-09, 07:59 PM #16
I love you guys. Always know how to make me laugh. Harlem go jack someone else's thread.