How many amps to my home for 75 S9s?

[.F.]

Hello,

I'm hoping to get 75 S9's in my garage. I'm planning all of this out and am trying to figure out how many amps I need to support that. Is it right I'd need almost 500 amps to my garage to support all 75 S9s?

I'm very confused on this math because I've seen many posts that say 400 amps support up to 100 S9s but that doesn't jive with what I'm calculating what I'd need.

Thank you!

[ccgllc]

Hello,

I'm hoping to get 75 S9's in my garage. I'm planning all of this out and am trying to figure out how many amps I need to support that. Is it right I'd need almost 500 amps to my garage to support all 75 S9s?

I'm very confused on this math because I've seen many posts that say 400 amps support up to 100 S9s but that doesn't jive with what I'm calculating what I'd need.

Thank you!

There are a LOT of post explaining this, but one more time, in round numbers:

Frequency * power consumption / joules per GH = chip power consumption
chip power consumption / power supply efficiency = 12V power drain, shy a bit for fans, the controller, etc.
wattage / voltage = amps (remember Ohm's law???)
breakers should never be continuously loaded for more than 80% of their rated capacity
wire should always be rated at the breaker rating (or larger, but nobody commonly does that)

so:

13500 MH* 0.098 J/MH = 1323 watts (just like the Bitmain page says)
1323 watts / 0.93 efficiency = 1422 watts, call it 1450 with fans an controller for this exercise
1450 watts / 220 volts = 6.6 amps
20 amp breaker allows you to use 12 gauge wire, which is easier than 10 gauge if you opt for 30 amp breakers
20 amps * 0.80 = 16 amps allowable per breaker
Therefore:  You can put 2 miners on a 20 amp 220V breaker

(75) S9s would require (38) 20 amp 220V breakers.

A 200 amp breaker panel has a 200 amp master breaker at top.  80% rule applies to that too, so 160 amps total usable per panel.

160 amps / 6.6 amps (which is pushing it to the limit) = 24 miners per panel or (12) 20 amp circuits, but...

A typical 200 amp indoor main breaker panel has 30 spaces, 60 circuits, 15 spaces per side.  Each 220V breaker requires 2 spaces, so you can only get (7) 220V breakers in per side, but that would overload the panel since 7 per side = 14 breakers = 28 miners = 185 amps which is greater than the limit.

You can find 20 space, 40 circuit 200 amp panels that work out better:  20 spaces = 10 breakers = 5 per side.  10 breakers = 20 miners = 132 amps which is comfortably below the 160 amp limit.

Using those 20 space panels would mean you would need (4) such panels.  To power them, you would need 75 * 6.6 = 495 amps of continuous draw power spread between those panels.

That is excluding power for lights, fans, etc. (not to mention the rest of your house)

Then there is the minor problem of getting rid of 1450*75 = 108,750 watts of waste heat, but that is a different discussion.

Oh, and dealing with the noise.

Moderator:  if you are willing, could you Pin this?

[.F.]

Wow - so probably over 500 amps to my home. I know it may vary, but is that normally possible for a residence?

By the way, I can't thank you enough for this analysis...

[SGMPhil]

500 amps to the house -  your power company is gonna love you!

[ccgllc]

Wow - so probably over 500 amps to my home. I know it may vary, but is that normally possible for a residence?

By the way, I can't thank you enough for this analysis...

Presuming you use natural gas for heat, hot water, and a dryer, avoid using AC in the summer, and have a fairly small house.  Most newer USA homes have 200 amp service for a reason, the oh-so-popular mini-mansions have 400 amp.

It also presumes your allowed to do light-commercial work in your neighborhood, which most won't allow.

Have you already ordered your miners?

[Raymond_B]

Wow - so probably over 500 amps to my home. I know it may vary, but is that normally possible for a residence?

By the way, I can't thank you enough for this analysis...

This is exactly why I recommended you find out how much you can get *before* ordering anything

https://bitcointalk.org/index.php?topic=2987899.msg30729483#msg30729483

[fanatic26]

Wow - so probably over 500 amps to my home. I know it may vary, but is that normally possible for a residence?

By the way, I can't thank you enough for this analysis...

Usually going over 400 amps to a home is expensive, you for sure need to talk to your local power company before you make any decisions.

Also, while the heat will be a problem, the noise will be much worse. I cant imagine you running 75 s9s for very long before the cops show up due to noise/nuisance complaints from your neighbors unless you live out in the cuts with no neighbors within a mile of you.

[.F.]

Called my utility company - they can do 600 amps at no charge (even for the transformer upgrade). I'd just need to pay for an electrician which I'd assume is $5,000 - $7,000 for the upgrade.

And for the noise, I'm going to try and insulate my garage with some materials that absorb noise and prevent noise leak (and then cover it up with drywall).


(Moderator's note: This post was edited by frodocooper to remove an off-topic portion of the post.)

[ccgllc]

Called my utility company - they can do 600 amps at no charge (even for the transformer upgrade). I'd just need to pay for an electrician which I'd assume is $5,000 - $7,000 for the upgrade.

And for the noise, I'm going to try and insulate my garage with some materials that absorb noise and prevent noise leak (and then cover it up with drywall).

You may be low on the electrician.  I had one quote me $10K to hang (5) panels and hook up to the transformer.  That did not include any breaker work inside the building beyond the panels.  Are you going to do all your own branch work?  Will your city permit that?

You can't do much about the noise due to the ventilation requirements.  I presume you have factored in something to deal with the ventilation problem?


(Moderator's note: This post was edited by frodocooper to remove an off-topic portion of the post.)

[.F.]

You may be low on the electrician.  I had one quote me $10K to hang (5) panels and hook up to the transformer.  That did not include any breaker work inside the building beyond the panels.  Are you going to do all your own branch work?  Will your city permit that?

You can't do much about the noise due to the ventilation requirements.  I presume you have factored in something to deal with the ventilation problem?

Yea, I have an HVAC engineer helping design. He's not too expensive because he's interested in this himself.


(Moderator's note: This post was edited by frodocooper to remove an off-topic portion of the post.)

[HoleShot]

Hmm, your HVAC engineer will struggle a bit with this. I calculated 32 Tons sensible cooling. I'd probably spec a 40 Ton nominal unit to handle the heat load. Cooling units over 5 tons are typically 3-phase powered. And if you found one, I'd not want it as it would likely fail too soon. You'd need 2x 20 ton units to cool this beast. Usually 20 ton units also have a reheat circuit to control humidity which requires more power than the compressor circuit when it's on.

When designing a closed system, where there is no air exchanged with the atmosphere, I start with 2X the IT load as the input power requirement for the site. This rule of thumb guess is a decent starting point to know about how large the input circuit needs to be.

So in rough numbers, I'm thinking about 800A, 3-phase @208.

Interestingly, I don't think your sound issue is as bad as some imagine. It's bad, but not as bad. Sound energy follows a logarithmic scale not linear. So 2x 30dB sound sources = 33dB and 10x 30dB = 40dB, 100x 30dB = 50dB. I didn't see the sound specification on their website so I can't do the actual calc. but that will not really matter much. It's based on the bel scale which is 10 times the sound energy = +1 bel over baseline, so 10 decibel is 1 bel.

Also, sound energy, like all unfocused energy, dissipates spherically in all directions equally. When this is measured linearly, like from yours to your neighbors house, the sound energy is reduced by the inverse proportion law, 1/r, where r is the radius of the sphere. So if you measure the SPL from 1 foot away, it should be a snap to calculate the SPL by knowing how many feet away your neighbors ears will be. When threatened with sound complaints, it's good to know your city's ordinances. SPL measured at the property line is really the calculation you should be determining before investing in a substantial electrical system.

[EncoreMining]

I would say not impossible but pretty improbable. A 20 ton unit takes up a 10x10 space minimum and needs to be a certain distance from property lines. The noise they produce is also much more then a small house system. My 20 ton units need 100 amps per phase in 240v service. Not many residences are equipped for 3 phase. It might be cheaper for you to find a small commercial building that already has that power. My building is 6000 sq ft and has a 1200 amp service already there. Good luck on your endeavors, hope you get it up and running.