Topic: [Group Buy] Avalon ASIC Batch 3 [CLOSED- Seven 4 module Avalons ordered] - page 19. (Read 49870 times)

I believe how it works is the utility's step-down transformer that supplies the house has 3 taps on it, one on each end of the secondary winding (the "legs"), plus a center tap (the "neutral").

To get 120V, you can wire a circuit using one of the two legs against the neutral.  To get 240V, you wire both legs against each other and leave the neutral out.

A typical house has a number of 120V circuits for regular outlets and lights and things, and then some 240V circuits for high current loads like a stove, heat pump, dryer, welder, etc.

By doubling the voltage on the high current circuits, the amperage is halved, so the wires don't need to be sized as large.  The tradeoff being that 240V is more hazardous to work with than 120V.

I could be wrong but I think the power lines in north america are three phase. I think residential homes are broken down into two or more "legs" each leg consisting of 110v to 120v single phase. Two legs can be wired together to power a washing machine or dryer on 220v or 240v. I think there might be a 10 volt variance allowed to allocate for voltage drops accross the wire. If coinhoarder lives in the US, he most likely has a 240v outlet in his basement for a washing machine.

There are two common electrical outlets that I am aware of in north america (I live in Canada). Single phase outlets that run most appliances. consisting of three prongs 110v + neutral + ground. Then the two phase oulet with four prongs. 110v + 110v + neutral + ground. There must be another outlet type for three phase for industrial purposes but I have never seen one.

They usually run 17,500 V on top of a pole.  This is from memory and I could not verify it just now--it may be 11,000V.  There are step down transformers every so many houses that feed 3 wires, presumably 240 V + neutral.  Every so many blocks the 17,500 is 3-phase.  There is attention to keep all the phases balanced and in phase.

I lived in this house in Oz that when the power went out in the street, often half the power still worked in the house I lived in

we were either on another phase...or something else, separate circuit on another phase it seemed...weird stuff I was pretty young but it did happen repeatedly in this fashion.

Im no electrician but I think to get 240v its just 2 120v lines tied together.

I spent 55 BTC on 2 lbs of coffee "back in the day", so I don't think it will be hard for this to beat that! Thank you again.

so excuse my us ignorance, do they have a mixed power supply there where they have a lot of step up transformers from the generators to give 240

or do they have 240 supply mixed in with 110v so dual lines or something

I'm powering 4 7950's with a 1500w PSU full load all day on a 15 amp 120v circuit in my apartment.  I have 2 20 amp circuits and a 15 amp circuit and could easily run 10 7950's off of that.  A 15 amp house plug can provide up to 1800w at the wall plug.  He's going to be just fine.

Wow you guys really don't know much about mains power if you think a modern US house is gonna be limited to 9.6kW.

The US standard for "regular" outlets is 120V, but they still run 240V into a most houses, plus a neutral leg which is used to make the 120V circuits.  A lot of the really high current appliances (electric stove, heat pump) are run on 240V circuits, for efficiency and to save on wire cost.

I have one of my "regular" outlets wired up for 240V, and I run my GPU miner on it when it's here.

I'm really glad to see a positive community action in the bitcoin world.

Congrats guys and all the best!

FINALLY out of newbie exile...

Australia is 230VAC single phase, same as here. Europe is 240V. 63A is the standard pole fuse on a domestic supply here in New Zealand and probably most 220V-240V countries. Loosely speaking, this gives most customers 15kVA of supply in ideal circumstances. In fact, even if you have a 63A pole fuse, your switchboard fuse is likely to be 40A to grade properly with the pole fuse. This give a practical upper limit of 9.6kVA

Electricity supply availability is a concern, depending on the actual fusing circuit breakers, CoinHoarder has. I'm assuming each rig is around 800W = 5600W or 5.6kVA, assuming unity power factor. If CoinHoarder's house is limited to 9.6kVA, boiling the kettle when the light are on will pop the fuse.

More of a concern, though, is dirty power. Yep, I deal with power quality investigations on a regular basis. In short, if a customer's appliance blows up, we (network company) have no evidence that the fault was caused by our network. In actual fact, it probably was but we have to tell the customer to make an insurance claim on the appliance (or "tough luck"). Advanced electronic logging meters will change all that in the near future. Meanwhile, say a voltage spike fries our mining rigs: Even if CH proves it was a network fault, CH can't make an effective warranty or insurance claim. It'd be at least a month or more before the rig(s) are assessed, new rigs built, tested, shipped and commissioned.

I think the idea of co-location was mentioned earlier. I had a quick look at facilities in the states offering 1/4 of a rack for $400/month. That's a pittance for round-the-clock care, clean power, physical security, gobs of bandwidth and backup generators. CH can still get his admin premium. I just want to mitigate risk where feasible to do so.

I guess this is a conversation we'll have over the next month or so before the rigs arrive. Looking forward to making an actual contribution to the network, instead of just speculating.

Sam.

If anyone is interested.....

I started my own group buy... But I would love to keep it at 2 units total.

https://bitcointalksearch.org/topic/avalon-asic-batch-3-group-buy-159378

Hey it wasnt your fault .. it was mine for sure.. You didnt put a gun to my head!!!

I looked at a bunch including bitinstant and just went with bitfloor.com since there was a bofa nearby.


i dont even know what happened.. I got put through the paces tho through the whole thing in terms of trying to come up with the loot and getting it in one account and the, anticipation and anxiety of making the cut in terms of availability... and the eventual heartbreak.

 Im afraid i have missed out on the legendary Avalon asic miner(AA#3). Luckily my group was only two other people. We teamed up to get 75BTC
Its a tough one to swallow but sometime it is what it is.. & doesnt always have to be something or someone to blame, but if theres anyone to blame its me.


Im just gonna have to wait till tomorrow to receive the BTC i guess.. and then ill have to chaulk the (fee%) 2-3% or whatever the fee was for $6k..
 as a loss when i convert back to USD to give folks their funds back.

Before i tried this i had pleaded with yufi to make an exception for wire transfer but no luck.. so my cards are played out even if i had another $6k which i dont!! haha..

I was hoping to get some feedback here https://bitcointalksearch.org/topic/bitfloor-cash-deposit-159340 but i guess that part of the forum doesnt get to much traffic.. I tried to delete it, since at this point ive bout given up.. dont even wanna look at the stock.

 Just hope tomorrow i can wrap up this ordeal.. Im in Cali so NYC is three hours ahead of me. When i come too from my comma i hopefully have chewed through some business hours and will have heard from them.
 
what can i say .. ya win some ya loose some and today i lost..

he said he had 30amp 240v circuit and a 60amp 240v circut

though i wonder becuase us has 110 - 120 v

240 v is Australian standard....he may not be in the US

I think in fact with 240 V coinhorder can not be in the US,
defn Oz


http://en.wikipedia.org/wiki/Mains_electricity

also I must confess a 60 amp circuit it pretty huge but it seems not uncommon

https://www.google.com.au/search?q=60+amp+circut&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

Yeah I did wonder/ask this

he quotes some figures for his amp on two circuits / 240V

but does not have 3 phase

here I found it

30amp 240v circuit and a 60amp 240v

so that is

60 x 240 = 14.4 KW

and

30 x 240 = 7.2KW

assuming he runs nothing else

7 x 650 = 4.55 KW

so he appears to have (14.4 + 7.7)/4.55 = 4.7 x off

however given he has house hold appliances to run and a lite coin farm, we need to say he woud apear to have 2 x of what he needs.

I would rather he had 3 phase though

because even in some blackouts/brown outs the other phases keep going