Topic: Using a 220V wash machine outlet for power..... - page 3. (Read 10781 times)

Good point you likely are right.

Usually dryer outlets are 30A,  I don't think I've ever seen one that is 40A.

As rjk indicated it won't be to code but it can be done.

First option: wiring to allow simultaneous use (dryer & miner)
To do that you really need to get some exact measurements.
a) peak current at startup
b) current when running
c) voltage at outlet
d) verify breaker is 40A

You don't need to derate the non-continual load (dryer).  So if the dryer pulled 3KW peak you could put 230 * 40 = 9.2KW - 3KW = 6.2 KW of miners on the circuit.  It won't be to code though.  A 30A (derated to 24A) PDU would work fine.  How much you can use depends on the EXACT measurements.  

Don't even think about doing this if you don't want to take real measurements.  You must know the voltage and current at the outlet.  Trying to guestimate it is a good way to waste your time only to find out you don't have the wattage available that you think you do.  Maybe your "efficient" dryer might be efficient because it uses more heating coils and recirculates the air so it pulls more not less than another dryer.  If you don't want to measure then just stop now.

Second option: switch between dryer & miner.

You could install a manual transfer switch so that either the plug for the miners or the plug for the dryer is energized at one time.  The switch prevents both from being used simultaneously so you have no overcurrent issues.  You would also want to use a PDU to connect all the miners to a single outlet to simplify the wiring.  If the miners are set to start after AC loss you would simply turn the switch to "dryer" (miners lose power), use the dryer, then turn the switch to "miners", and the miners power on automatically, boot, and start mining.

You want to make sure the switch has higher rated voltage than the breaker and either load.  On edit: you indicated 40A but it may actually be 30A.

http://www.solar-electric.com/miso60amp240.html

Normally transfer switches are used to switch the source (i.e. utility or generator) but electricity doesn't care about direction.  The transfer switch would allow only one to be used at one time.

So currently:

With transfer switch

* dryer outlet is actually 120V/240V combined it may be either 3 or 4 wire (4 wire is newer/safer).  Miners would be connected to a NEMA L6-30R outlet (30A @ 240V only).

Now nothing you do will make this code compliant but if it were me I would feel better with the transfer switch.  No the possibility of pulling >40A through the circuit.

Third option:[/u]
Just run a new line to the utility room and install a dedicated outlet.

I will have to get that info tonight.....It is a Samsung, about a year old. 

If he's got a fancy front-loader that's a high efficiency model, it's actually pretty likely that it's running a brushless DC or PMAC motor. The nicer white goods have been moving in that direction for awhile, I don't think many new front loaders have been made with shaded pole motors.

What's the model of the dryer, yochdog?

Thanks!  The advice is appreciated!

There might be - but Code requires a dedicated circuit for a reason.

See if you can find the nameplate rating of the device, just to be sure of the wattage.
Most dryers use a capacitor-start motor that runs at a constant speed - such motors make all kind of nasty electrical anomalies when they start, not to mention a large additional power draw. The motor might take up to 400% of its rating during the few seconds that it is starting, and that would trip the breaker if you removed the additional overhead allowance that is already built into the circuit by running some rigs on it. Now obviously, the motor isn't the main load - the main load is the resistive heater inside, which switches on and off to maintain different temperatures.

If we assumed that a 40 amp 220v circuit could supply approximately 7KW of power (after derating), and if we assumed that the dryer was 2KW like you mentioned, you should also assume spikes of up to 3KW during the motor start phase for a few seconds. This leaves you with potentially 4KW of "spare" power. You might be able to open the power outlet and add some #8 wire to extend the branch circuit to another plug. However if you do this, you really need to get a PDU with its own circuit breakers built in, otherwise you risk fire from under-rated wiring. I wouldn't want to suggest more than 20 amps of 220v coming off of the PDU in this case, since it isn't dedicated.

Finally, if you do this, make sure you have absolutely top-shelf PSUs. Since they will be so electrically close to the nasty power spikes caused by the motor starting, they will be more susceptible to failure.

20 amps at 220v should allow you to run several rigs. Good luck, and don't let the inspector see it!

I have the insanely efficient stuff.....the dryer might use 1800 watts, 2000 at most. 

I believe the 220V is on a 40 AMP breaker, so shouldn't there be PLENTY of headroom for some miners? 

LOL, switch back and forth... Do you know how much power that dryer uses?  You might be able to run maybe 1 card with it running.

So I have this fantastic utility room with lots of space, great ventilation, and a big ole 220 volt outlet. 

I would like to set-up some miners in this room, but I want it to fit in seemlessly with my wife's lovely (and massive) front loading spaceship looking washer and dryer. 

Anyone have some experience splitting the power outlet so multiple appliances can be hooked up?  I really dont want to have to switch back and forth everytime we have to do laundry. 

It would be great to run the miners off of the same outlet without doing too much re-modelling!

Any advice would be great.