Topic: US residential miner power budget (Read 1018 times)

I wish the OP would specify, but I imagine this circuit is already in place if they are asking about a single 15A circuit.  I find it doubtful someone would go out of their way to wire a new circuit, and only have it be a 15A one...

Anyways, the 80% rating on breakers and house wiring should already take into account the increase in temperature of the wire between the receptacle and the outlet as well as voltage drop.  80% is 80% and is code (which as others have alluded to, leaves some room for safety on top of that in our experiences, though not recommended). Meaning as long as your voltage at the wall is in fact 120V, not 110 or 115, you are fine to run an S7 off it which will only draw ~1200W give or take depending on the batch INCLUDING PSU losses.

Dam nice catch i forgot about the rating my 8.2 and 12.2 i use both are rated at 600 V, i completely forgot about that and when i bought my wire, i made sure it was at least  600 Volts.

I would install a 20amp plug with 12/2 wire line from the box on a new 20 amp breaker, dedicated. 

My home is 1970 a Vietnam war copper shortage in the USA made for many homes like mine to be made with Al wire.

I actually had some 14 ga Al wire!
Most was 12ga Al wire.
The only copper was a 6 ga copper 240 line for my central air conditioner.
I  was an audio freak [I still am].

So I put in all copper 10 and 12 awg. I went from a 20 breaker 100 amp to a 40 breaker 150 amp.

I knew I had gas cooking and gas clothes dryer so I went for 150 amp.

I recently changed 2 breakers from 120 to 240 volts.
I don't have a lack of power and circuits for my miners.
My biggest issue is price 17 cents in the summer. 10 cents in the winter.
Cooling is the next issue.
I could run ten s-7's off my two 30 amp 240 volt circuits.
I could also put a sub panel in on my 6 ga ac line giving me a third
30 amp 240 volt circuit.
The point of my post is Al wire is really bad compared to Cu wire.

Good point, I have never seen 300V wiring but that is a good warning.  I also agree with another poster do nut run AL wiring in your home.  The heat expansion will cause the terminals to loosen over time making a fire hazard.  If insurance sees AL wiring inside your home, they will most likely deny your claim also. Copper is much better, I prefer it in all my installation even when AL is allowed.

 And check that the wiring is actually rated for it - MOST commonly-used wiring is insulated to 600 volts which is plenty, but I have seen rare cases of 300v insulation WHICH IS NOT SAFE FOR 220V AC.

 A "nominal" 220V AC line will often see RMS voltages around 240V, which gives a peak voltage exceeding 330V - and that's assuming NO spikes at all.

 Not in the USA.
 Aluminum wire OTHER THAN for the downlead into your panel is no longer accepted for inside residential OR commercial wiring by the NEC - that changed ballpark 20 years ago.
 DO NOT USE ALUMINUM FOR NEW INSIDE WIRING.

 Most local codes follow the NEC, so "most codes" do NOT treat 12 AWG Aluminum as the same as 14 AWG copper any more.

 If you have an older home (usually a mobile home) that still has aluminum wiring, be VERY VERY cautious about it, it was NOT generally derated ENOUGH for safety when the ambient temperatures got high.

 14 AWG copper is spec for a 15 amp circuit - 12 is spec for a 20 Amp, and NEC specs tend to be quite conservative.

 There is NO NEED to downclock a Batch 6 S7 to run on any standard 15 amp circuit, unless you are using a power supply with efficiency a lot worse than BRONZE level.


 I do tend to overkill on my own "add wiring" setups and use 12AWG on 15 amp circuits - but that's mostly 'cause it's usually only a very little more than 14 AKA cheap insurance, and it saves a hair on voltage loss.


 200 amp service has been common for most homes for some years now.
 The only things I've seen with 100 amp service in semi-recent years have been mobile homes, and even THOSE are starting to go 150 amp on some of the higher quality ones (or ones with electric heat), or places that had electric put in decades ago.

Also keep in mind you can go a little above 80% and still be fine.  Your breakers will trip first as they are rated for 60C unless you get commercial gear in your house.  The wiring itself is usually THHN rated for 90C. 

I would turn the circuit into a 2 pole breaker provide 240v, so you get double the watts.  That is assume the branch circuit has plugs only on it, lights and fans will not survive 240v.

I thought he was offerring advice for miners.

If you order a batch 6 at 4000gh and 1100 watts  to run it on 14 gauge wire would mean the nessicity to downclock it to 3600gh using 950watts.

That would be safe .

I was just thinking that to, he wants to run a S7, if i understand it right, he might get a way with it but i wouldn't over a 14 G wire .


like you said, if that's his only option , that will turn out bad and cost more then wanted .







later

10 gauge wire is too fat for many of the terminals made for this stuff you find at the local Home Depot, but yeah 10 is better as much as any larger wire size and is what I used to make the first section of my two section whips for my power supplies.

I do not think the OP has the options to use whatever he wants, I think he is saying this is what he has, and in my opinion it is too tight. No room for error and I do not run anything that way.

Which is why I asked him to clarify.

Use 10 it safer and cost about the same but that's me.


as some one said once :

you can lead a horse to water but you can't make him drink it.. ...


Just a tip on the wire, he can even use a 110 20 amp over a 10 gauge, which gives a tad more power and a lot safer.

only use that line for mining .

Later

If It were mine and all I could mine on is 1440w using 120 vAC I would use 12 gauge copper.

Or, are you saying the circuit is already there? The 14 is already in place?

Maybe clarify the question a bit.

have a 240 line put in if you own the house and can . with a 220 depending on the miners you can plug 12 or more into one line depending on the amps .


not really much you can do with a 120 maybe plug in 7 to 8 miners safely before you would need a 220/240 line .



Don't forget to factor in the home service 100, 150 , 200 amp or 400 is more for business but poss  to have put in your home but might cost any were from 1500 to 3000 K, depending the state and what you need.

Stay with copper, I was told by a electrician it's better and safer then aluminum . might cost more, but that's why. .  it might cost you tops to have a 220 30 amp or higher, 80 bucks parts included, I also had my 220 30 amp line run with 8.2 wire in case i decide to swipe out the plug and the breaker to a 40 or 50 amp   , it cost me 45 to have one run, but i had the parts.



if you mine in your home don't use 12 use 10 gauge or lower for either copper or aluminum the wires will heat up even if it's 12 gauge. 14 is real bad for mining or any thing that is not every day use . trust me 14 gauge will melt under a lot of stress . i had 3k running over a 10 gauge wire till I found out how unsafe that was for a 110 line, still don't know how i was able to, but i did it. but that was when i first stated, now i balance out all my miner on a PDU , last thought there are PDU's for 110/120 lines that are safer then the normal plug in, that don't cost to much.

The point of all this is to utilize a single residential 120V 15 amp circuit which has a continuous use limit of 1440W.

B6 S7 specs:

a) Efficiency: 0.25 J/Ghz +10%

b) Hash rate: 4050 Gh/s


Power budget:

a) Miner: 1045 watts best, 1150 watts worst

b) 1300W power supply, 120 watts

c) Wire power loss (14 gauge@12 amps@ 50 ft) 36 watts (nifty calculator: http://www.calculator.net/voltage-drop-calculator.html)

d) Amp carrying capacity correction (NEC table 310.16)  ?


Total budget:

a) Best: 1045W + 120W + 36W (wireloss) = 1201W

b) Worst: 1150W + 180W (85% efficient power supply(s)) + 36W (wireloss) = 1366W

The worst case gives about a 75W margin.


Other considerations:

a) The resistance of copper changes by roughly 2% for every 5C.  Conservatively, heating a wire by 5C reduces the current carrying capacity by about 36W.

b) 12 gauge aluminum wire is treated as being equivalent to 14 gauge copper by most codes.