Topic: Residential Limit 15amp or 20amp? - page 5. (Read 13249 times)

Then you are probably in good shape unless you live in some huge-assed place with electric heat, and charge electric cars, dry your clothes, run a half dozen hair dryers all the time, and have 89 inch tube TV.  

the main breaker in my box is 200 AMPs 

A home wiring book will explain all this, it's really not as complicated as it seems.

If you stick to 120v....:

Remember that anybody might have put either a 15 amp or a 20 amp breaker on the same 120v circuit, but that circuit might be more appropriate for 15 than 20, when the size of wire and/or ratings of outlets are taken into consideration. So the existing breaker size doesn't necessarily give you the information you need if you are thinking about constantly running the circuit at or near max.

I would have 12 ga. wire on a 120v 20 amp circuit that I was going to push hard, and not spindly smaller stuff, and I would aim for that circuit to be dedicated to a single outlet.  That's ideal.  (Obviously you need 10 ga if you move up to 240v.)

What else you have on the same circuit matters!  You can't run max load on one outlet while another outlet on the same circuit controls, say, the dishwasher... or you plug a vacuum cleaner into it!  If you do that, then you may pop the circuit.

Space on your breaker board doesn't necessarily mean you have that much unused overhead in your service.  What matters is the load you put on the overall house service - all your electric demand put together compared to your total house service.

If you want to know the amps of your overall service, locate the box where electric service enters your house.  There should be an indication there. You may need to open the box door and take a look at the 'big breaker' there.

If you've got the ability, I think D&T's suggestion makes sense.  Personally, I've got a few solid 120v circuits on new 12 ga copper (which I wired myself!) that don't have a lot of load on them, so I plan to run a couple of miners on them, rather than going to 240v.

DeathAndTaxes !!


Thanks for clearing that up and going into detail! I should have figured there was a cushion required.. hence the 1920w.

As you can see im not the only one who's benefiting from your feedback! Thanks for being so generous with your knowledge.. somehow i think your just being yourself but i appreciate it nonetheless!!!
 



 5760W of mining power, done right and safe.  ( FTW!!! )  

Well, blue smoke is pretty fun....

What?

You don't like fireworks and the smell of fried insulation?

You're no fun at all!

Oh, don't plug 110 devices into 220 power.

No.  In the US a continual load can't use more than 80% of the circuits capacity.  I just realized the 0.8 got changed into a smiley so I fixed that.

So in the US a 120V, 20A circuit is rated for 2400W PEAK however continual loads should not exceed 80% of that  2400W * 0.80 = 1920W.

Higher current = higher heat.  House wiring is sized under the assumption that the load will vary and that is easier to cool.  Now you "can" pull 2400W from a 20A breaker continually but that would be a violation of the NEC as the wire would be under greater resistance that intended for continual use and the breaker won't trip.  In theory if the wiring was substandard, or faulty, or corroded due to age it "could" cause a fire.  Now the risk is probably pretty low but the Electrical Code is designed to be conservative because it involves people's lives.  

I have no knowledge of European standards, outlets, or ratings but current, resistance, heat are pretty much universal so the same general concepts still apply.


Other than the 20% derate for continual loads, yes.  So the 1920W not the 2400W is the correct figure if you are running a load continually (like a 24/7 miner).


No.  NEMA is Noth American Electrical Manuacturers Association.  They are all US outlets.  The NEMA 5-15 is the "standard" US wall outlet.  The NEMA L6-30 is a 30A, 240V outlet which uses a locking connector.


Here is an example I just like the photo not trying to give this seller any business:
http://www.ebay.com/itm/APC-AP9571-1U-Rackmount-PDU-208V-24A-12-C13-Outlets-/261343426014?pt=US_Power_Distribution_Units&hash=item3cd94835de

There are tons and tons and tons of this PDU (PDU = fancy name for datacenter high current power strip).  APC probably makes a couple millions so there are always used ones on ebay for cheap.

It has a NEMA L6-30P plug.  The plug is rated for 30A but you will notice in the description it says 24A.   Why?  NEC requires that continual loads be derated 20%.  30A * 0.8 = 24A.  24A * 240V = 5760W.

Note the official specs are 208V because they were designed for datacenters but they work fine at 240V as well.  It is simply a "power strip" with circuit breaker there are no electronics which require a specific voltage.  


So:
30A breaker ------> 10 AWG wiring -------> NEMA L6-30R outlet ------> AP9571 (w/ L6-30P plug).
You now have 5760W of mining power, done right and safe.  The PDU gives you 12 outlets so no matter how your rigs are configured you are good to go.

I ran 12KW of GPUs off three of these.   

Just checked the panel box in basement... I've got room for 9 more breakers!

D&T, im stealing this.

Oh i see!! Forgive my ignorance..

You can have 240 installed in homes in the USA as well. This is what electric dryers run on.

DeathAndTaxes! Thank you for your input its very much appreciated! You guys seem to have a serious grip on electricity !!


if im not mistaken 120v is for the USA and 240v is for EU. So on the list you made the second one applies to me right, im in the states..?

120V 20A = 1920W  120*20*0.8

Do you mean: 2400w


Does that mean on one socket i cant go above 1920w 2400w! Is there some kind of ettiqute in terms of leaving some cushion or can you go pedal to the medal and use all the juice it can give?



I take it this is for sockets in EU and not US, same with the connector on the pdu? ( NEMA L6-30R )

This is excellent advice. I am moving to a new home in a few weeks and that is the 2nd modification I am having made to the basement. 2x 30AMP 240V circuits.

You are correct but I was referring to the average residential installation, which is what the OP is dealing with.

Thank you for your input and advice.

Many people will plug in a power strip to an ordinary outlet, hook up a toaster, a coffee pot, a waffle iron, a microwave, a small TV for the ktichen and then wonder why the breaker trips or the house burns down and we don't want any of that!

Thanks again for you post as it contains very important information!

My $.02.

You can't make a statement like that.  It depends on the outlet.  Continual loads should be derated 20%.

120V 15A = 1440W (120*15*0.8 )
120V 20A = 1920W (120*20*0.8 )
 
240V 15A = 2880W (240*15*0.8 )
240V 20A = 3840W (240*20*0.8 )
240V 30A = 5760W (240*30*0.8 )

There are 40A and 50A outlets but they are expensive and it is hard to find cost PDUs which match.  If you are running a custom line have an electrician (or DIY if you are competent) install a 30A breaker, 10AWG branch line, and a NEMA L6-30R outlet (240V, 30A, locking).  Then pickup a cheap used datacenter PDU with a NEMA L6-30P plug.  Good for a solid 5.76KW.  Better yet install two and you are covered for 11.5KW.  That should be good for 14 TH/s or rigs @ 0.8 J/GH.  Beyond that your largest challenge will be cooling not power.  

Hey, man, we are 100% cool and thank you for your kind response!

I think from the looks of your box that you got 100 amp service but check it out.

Yeah, I have gone maybe crazy over mining but to use a trite phrase, it is "the wave of the future" for at least a while and long enough to provide myself, my associates and anyone who chooses to do business with us with comfortable retirements.

Hit me up any time and I'll do what I can to help you.

Hey thanks for chiming  in everyone!


Lostdutchman you are right.. i was confusing the capacity of individual lines with the total incoming!
( i clearly have more homework to do)

btw, holy crap you got a crazy setup.. I wish i had a basement, it would be on..

 my house was made in 85 and its about 2500 square feet.... this is my panel!



 

bedrooms and family room labeled 15 and the garage is 20. I have a one labeled dryer that says 30.

Hopefully i can add or upgrade the garage or the bedrooms without replacing the whole panel or paying thousands to have a wiring change.

Im thinking about setting up shop in the garage but i work from home and thats my office so i dont think i can stand the noise.

I guess right now the first rig will be fine.. @2100w in either the garage or bedroom.. ( maybe i can wheel it over to the garage from the bedroom when i sleep lol )


I planned on sucking down about 2100watts to start and then gradually bring in more replica rigs adding 2100watts each!
Im not going too nuts yet.. but i would like to get up to 15-20mhs if i could depending on any hurdles that may arise. Im eying a couple alt coins i want to mine.. so ill be splitting the task between the two.. 

Thanks again for the input everyone .. im going to do what lostdutchman suggested and ask the power company what amp service im getting. After that hopefully i can get the first rig setup and start thinking about a long term power plan. Im waiting for my gear to come in so i wont get started till the 13th or so..






 

No, the houses all have basement garages with overhad doors which we have closed up now with proper insulation, etc.

We are going to do primarily altcoin mining with at least some ASIC rigs, providing that such equipment is available in a time frame which ensures profitability before difficulty becomes to high.  We are in negotiation with several ASIC manufacturers to provide us with at least prototypical equipment for real-world live testing but the outcome of those negotiations remain to be seen.  Tell you this though, anyone who will work with us is real and we will promote them in return.

Scrypt equipment can be constructed from readily available components and the Scryptcoins converted to Bitcoins if desired, so that is the road we are going to follow with Lost Dutchman Mining.

If someone orders a given hash rate the lag time is less than two weeks from cleared funds to active mining and most of that is shipping time of the components and assembly.

We can also get additional 400 amp services into the houses at residential rates by operating home-based businesses for which we will be licenced.

Anyway, long day here in Brownbackistan; the new name for Kansas since we now have an idiot for a governor.

Check you later!