Power Distribution: House to server rack

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X8XFoundries

Limp Gawd
Joined
Mar 4, 2025
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I am trying to put a map together of where the plugs are on the 3rd floor of my house. Everything is split, so one floor isn't one breaker, its maybe 2 or 3, depends. 3rd floor is 2, floor below is 3, maybe 4.

While I am aware that I am unlikely to slam the 20 amp circuit with a single server, I AM likely to slam it with a server, a mac pro, a G5, and the massive squirrel cage fan that is the current attic fan for the house. (I am working on a proper exhaust using a smaller squirrel cage, a bloweymatron, some hosing, and a box I am building)

How do I add up everything? As in, my R510 has a redundant supply, 10 amps each, so is that a 20 amp thing right there? Thats obviously only at full load.... right?

A G5 I think is 5A, a 1,1 is also 5A. The networking equipment on the rack all adds up to 4.5.

But is this technically only at full load?

I can run power from other rooms and not be obnoxious about it, I'm just trying to figure out how exactly this adds together.

For note, this is not the final installation, there will be a proper rack and power drop in the basement, but this is what I am working with over the winter. Take advantage of the thermals while I can you know?
 
Without going too deep into the details, here's some general stuff from my limited knowledge when I was looking at this for other things. As a rule of thumb, for peaking loads you add up all of the maximum currents and make sure your breaker is large enough for that. The reason is because you don't know if they might peak all at the same time. For continuous loads, you want to use the 80% rule- your continuous load should be less than 80% of your breaker capacity.
 
Tsumi said:
Without going too deep into the details, here's some general stuff from my limited knowledge when I was looking at this for other things. As a rule of thumb, for peaking loads you add up all of the maximum currents and make sure your breaker is large enough for that. The reason is because you don't know if they might peak all at the same time. For continuous loads, you want to use the 80% rule- your continuous load should be less than 80% of your breaker capacity.
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Excellent rule to remember.

I got some pointers from another forum, and some ideas from my mother. I am going to get a ring tester to double check which breakers go where, then map out the plugs, then determine my supply max. I would like it if I COULD run the machines at max amperage. That doesn't mean I will, nor that they are actually capable (lower sku G5 etc), but that I CAN with no worry means I can leave the premesis and not have to worry.
 
I had an electrician install a 14-50r and a 110v 30a next to ours while they were here doing other stuff after lunch so they could take the day off on a Friday by doing piddly stuff like this after lunch and it cost a whopping $100 due to lunch + beer +fluffy dogs.
 
Wade88 said:
I had an electrician install a 14-50r and a 110v 30a next to ours while they were here doing other stuff after lunch so they could take the day off on a Friday by doing piddly stuff like this after lunch and it cost a whopping $100 due to lunch + beer +fluffy dogs.
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If I get my own breaker box it won't just be one breaker. It'll be like 4 or 5. 50A total. At least thats the plan
And not my plan, thats just what my dad has laying around.
 
Can you balance loads between the two circuits you mentioned above?
Also note that the numbers on the back of the PSU are usually max draw ratings, not what the machine constantly pulls.
Your R510 with dual 10A supplies doesn’t mean it’s slurping 20A all the time; it just means each PSU could handle up to 10A if needed, in practice it's less than that unless you are stress-testing.
 
saintobi said:
Can you balance loads between the two circuits you mentioned above?
Also note that the numbers on the back of the PSU are usually max draw ratings, not what the machine constantly pulls.
Your R510 with dual 10A supplies doesn’t mean it’s slurping 20A all the time; it just means each PSU could handle up to 10A if needed, in practice it's less than that unless you are stress-testing.
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I was given a pretty good run down on Toms.

Your in-current has a max rating, but its actually not all that often that a machine can seriously hit the rating. Someone had mentioned their same box with 8HDD's is like 100W.

What I would like to be able to do is hit max and not have it be an issue. So the reason I am asking anything at all is to figure out how many leads I need.

I have 15A circuits in 20A wire, and 3 or 4 are accessible from the server room, with some work.

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Ok heres the plan.

Theres the 2 attic rooms, both are on the same 15A circuit. At the bottom of the attic stairs is another circuit I can plug into with a jump and just run up the stairwell, giving me 30A total. I won't be able to do input max, but doing the math here, rough estimate, most of the power supplies in each machine is severely overpowered for the job that it has.

At most, I will try to move the modem + gateway/firewall into the hall way and redo some of the cables and LAN routes. I think everything will work fine, I'm just nervous about a failure killing something I CANNOT replace right now.
 
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X8XFoundries said:
I was given a pretty good run down on Toms.

Your in-current has a max rating, but its actually not all that often that a machine can seriously hit the rating. Someone had mentioned their same box with 8HDD's is like 100W.

What I would like to be able to do is hit max and not have it be an issue. So the reason I am asking anything at all is to figure out how many leads I need.

I have 15A circuits in 20A wire, and 3 or 4 are accessible from the server room, with some work.

-----------------------------------------------------------------

Ok heres the plan.

Theres the 2 attic rooms, both are on the same 15A circuit. At the bottom of the attic stairs is another circuit I can plug into with a jump and just run up the stairwell, giving me 30A total. I won't be able to do input max, but doing the math here, rough estimate, most of the power supplies in each machine is severely overpowered for the job that it has.

At most, I will try to move the modem + gateway/firewall into the hall way and redo some of the cables and LAN routes. I think everything will work fine, I'm just nervous about a failure killing something I CANNOT replace right now.
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In the USA we don't measure wires in amps, it's measured in AWG and usually for 20a you want 12ga or 10 if it's really far.
 
Wade88 said:
In the USA we don't measure wires in amps, it's measured in AWG and usually for 20a you want 12ga or 10 if it's really far.
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My family is all machinists, so we grade amperage by wire grade. 20A can be all sorts of quality.
 
Wade88 said:
I had an electrician install a 14-50r and a 110v 30a next to ours while they were here doing other stuff after lunch so they could take the day off on a Friday by doing piddly stuff like this after lunch and it cost a whopping $100 due to lunch + beer +fluffy dogs.
Click to expand...
Just to echo this, if you have concerns about your setup or want total peace of mind, just get a quote or two from an electrician. A quote won't cost anything and you might be surprised how cheap the work is to do a proper power run to your rack or your basement idea. I had a bunch of extra electrical work done last year because the prices ended up way more reasonable than what I had budgeted for.

Running long extension cords is workable but only as a temporary solution... when someone trips over that cord / yanks it / abruptly interrupts the power your hardware can go tits up (ask me how I know :banghead: )
 
SamuelL421 said:
Just to echo this, if you have concerns about your setup or want total peace of mind, just get a quote or two from an electrician. A quote won't cost anything and you might be surprised how cheap the work is to do a proper power run to your rack or your basement idea. I had a bunch of extra electrical work done last year because the prices ended up way more reasonable than what I had budgeted for.
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I actually didn't know a quote would be free!

Probably instead of having my dad do a new box, I'll have someone do it proper lol. I really want everything done right at some point.

As of now I have 3 circuits combined in one room, the R510 power supplies are on 2 separate circuits completely, the network stuff is wired to my room, and the servers all go on a circuit that currently has nothing on it whatsoever. If my amp reader was right, the load is spread out so much nothing can be a problem!

I am also working on getting GFCI's from AC units so I can mod them to be mid-breakers until I have the basement ready. Can only pay to be safe!

And every line has at least 2 surge protectors.

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Also wade, I don't appreciate being jabbed at in a thread. If you have a problem with me, pm, or drop it.

Thank you.
 
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