Bitcoin Forum

Hardware:
Currently running a rig that is drawing 1800w from the wall. (denoted rig 1)
Want to build a 2nd rig with similar power draw. (denoted rig 2)
ONLY two separate circuits available to use. (denoted as circuit 1 and circuit 2)
Both circuits are 20AMP rated so each can provide 20AMP*120V=2400W. (2000w for continuous use to be safe)

Usage:
Rig 1 is taking circuit 1 from a wall outlet. And some other small stuff for normal home use also draw less than 200w combined(all turned) from other wall outlets wired to circuit 1. So I am looking at 2000w from circuit 1 (1800w for continuous use).
Thus I can't put 2nd rig onto circuit 1.
Unfortunately, due to the location of the wall outlets wired to circuit 2, I'd really like to avoid using that.

Question: How do I make both rig 1&2 using circuit 1 only without overloading it? (Note: the rigs are used continuously and draw 3500-3600w combined. And also some other stuff mentioned above drawing another 200w. So I need circuit 1 to provide 4500w to be safe to continuous use)

My proposal:
Use a heavy duty and high quality, say 5000w, transformer to convert the 120v(from the outlet I will be using for both rigs) to 240v. (Other small appliances are unchanged)
This way, that outlet should be capable provide 20A*240V=4800w of power and then the needs of rig 1&2 are satisfied, plus the PSU will operates more efficiently at 240V.


Will this work? I mean I just multiplied the amp with voltages, is that simple? Or do those 20AMP ratings really mean 20AMP at 120v only...
What potential problems it will cause? Things like frying the whole circuits, or the rigs?
(Remember I am only converting the voltage of the outlet on which I will be using for rig 1&2. There are the other small things will be using other outlets, but also wired to circuit 1)

Things like range will take like 7000w, or even 10000w if everything is on and high. It must be used with a higher AMP circuit, but even at 40AMP it is not enough at 120v. So an electrician use a step-up transformer for this correct? Basically what I am doing for my rigs.

If your answer is yes, and be able to explain the situation professionally(at least somewhat). I will send you 0.02BTC.
If your answer is no, and be able to provide a good solution that costs less than $200. I will send you 0.02BTC.

That 1800 watt load for one rig is the maximum you should run on one 120vac circuit, if you have two separate 120v ac circuits from the breaker box then just run each rig on a separate circuit.



If you where to buy a specialty transformer to setup the 120 circuit to 240 you are still limited by the power on that single circuit.  Your voltage might double, but your power will stay the same minus loses in the transformers and such.  You would only have a max 2400 watts but much less because of loses.

If you have 2 circuits just get on with it.

I mentioned explicitly that I don't want to use it on the 2nd circuit at my home because of those outlets are at kitchen.

You have to look at watts.  If you turn 120 into 240 using a transformer you can only run half the amps not twice.

At the breaker box you get 240V, you have to run it all the way from there.  You'll see single fuses that supply 120V and double fuses that supply 240V.

No. The power is constant. You'll get the same wattage from the transformer + some amps for conversion. You can't drain more power from the outlet. The transformer will consume 17 amps, when your pc will bet 8 amps with 220 through it.

you need a separate circuit for each rig, hire a electrician to run a new circuit to where you need it.

  make it a 220v circuit while you're at it - most if not all psu's will like that (run cooler, more stable) and consume only 1/2 the amperage used on a 120v line  :)

Agreed. You need new circuits installed. What you have installed now isn't good enough. I know it's not the answer you want, but realistically, there is no alternative.

I strongly recommend the use of 240 V outlets. PC PSUs operate more stable, more efficient and cooler when powered on 240 V.

In addition because of the lower amp requirement of the PSUs when operating at 240V it allows more flexibility in moving PCs from one circuit to another.

No. While your "transformer" will be delivering 20 amps at 240v, it will be sucking 40 amps at 120 volts from the wall to do it, thus overloading the circuit. Watts in = Watts out. Assuming your transformer is 90% efficient, if it was sucking 40 amps, it will only be delivering 36 amps + heat. Also, I do not think a transformer that size is under $200.

Note: 120v is not really 120 volt. It is really 110 - 120 volts, and could be lower during brownouts. So, if you want continuous load, you should be thinking 110v x amps, or even 110v x amps if your area has bad power. If so, you should be using power conditioners to protect your rigs, and that increases the power draw at the socket.

One possibility, but only if this is your house, since it will require electrical work:

You could convert the 110 to a 220 volt outlet. If you are not too far away from the electrical box, you could run a second hot line, and connect it into the other phase coming into your house. Then change the wall socket from 110v to 220v. If you have conduit, it could be relatively easy.

Note: It is not that much more difficult to just run another 110 circuit. But, if there are conduit limitations (too many wires in the conduit), then only having to run one more wire could be the solution.

Another possibility is to get another 110v outlet on a new circuit near the electrical box, and run a really heavy duty extension cord.

Need to drop a new circuit, plain and simple. 120 or 240 is up to you. It's not hard. You need to make sure your panel has space for whatever breaker you want (one space or two space) and make sure your plugs are compatible with whatever outlet you choose.

Another option is to buy one of these:

https://bitcointalk.org/index.php?topic=424987.0

80 watts to mine LTC at 3Mhs. From this person it is cost competitive with GPU mining (although it has much less residual value).

Note to self: when needing help, don't offer bounties upfront.  

You don't get to keep that 20A man. Voltage goes up...current goes down. There is always a trade-off.

You clearly need a transformer.

If i had to choose i'd take Optimus Prime.

simple, run cables from the kitchen to wherever you want to set it up