Topic: For 4 mining rigs (GPUs) plug on 120V/20A outlet which PDU to use for safety? (Read 231 times)

Tha flash you saw, either a surge or a brown out, might be a concern. It may have been a nearby lightning strike,
an electric motor like a fridge starting up or a problem with the grid. If it isn't an isolated incident and is enough
to crash your miners you may need a UPS.

You can do the math about the other stuff.

So guys thanks for you help, final words here.

If I try to run 3 mining rigs let's say total 1920 Watts on a 120V/20A circuit is it dangerous for the equipments if I get voltage sag?

In the future I will do my watt circuit calculations based on 110V or 220V with 80% rule.

Last newbie question, my electrician changed my electrical panel from a 150Amp to a 200Amp does it mean that the total current I can use in the same time is 200Amp? And if in the future I use close to 10kW in my garage for mining, is it enough a 200Amp electrical panel to power the rest of the house without issue or I will have to upgrade my electrical panel again?

Peace out!

Hey merci beaucoup (thanks a lot) philipma1957 !

Ho yes you are right, I can see on my PDU Remote Management (I connected my PDU with an Ethernet cable to my LAN), a graph showing the voltage fluctuation and it ranges between 117.5V to 122V for the last day. Plus, yesterday something strange happened, I was reading in my living room then the light flashed so I was worry, I checked on HiveOS app on my phone and my rigs were disconnected. I went in the garage didn't understand what happened, I did a hard reboot and everything went back to normal. I only have 2 rigs for now for a total of 1250/1260W.

When you write “Since your mining gear psu's can handle more power I don't worry if you drift upwards to 125 or so it is if you drop to lets see 115 is 115 x 20 x .8 = 1840 and your rigs pull 1890  do that for 1 hot week you will pop breakers.”

But if the voltage drops at 115 Volt so the 80% rule won’t stay and I will be using more than 80% of total power capacity isn’t?

Okay I think I understand so for the same Amp if the Voltage goes down to keep the same power (Watts) then the current or Amp will go up.

For instance:

Scenario 1: If I draw 20A on a 120V I get 2400W (let's ignore the 80% rule for the sake of the example).

Scenario 2: For the same 2400W if the Voltage goes down to 110V then to keep 2400W the Amp will go up at ≈ 21,82A hence 110V X 21,82A ≈ 2400 W

Haaaaa.....

philipma1957 you are amazing thanks! I would give you a merit on this forum but I am still a newbie and don’t have merit to give.

So I think I finally understand the whole story about the Voltage. When we say 110V/120V or 220V/240V it’s in fact a range (minimum/maximum) which depend on heat and wire length (and wire gauge I guess).

So yea I think I will do what you suggest “upgrade 2 and keep 2” i.e. keep 2 circuits of 110/120V 20A and upgrade/change for 2X 220/240V 20A circuits.

It’s great doing that because I already bought 2 CyberPower PDU41002 Switched PDU, 120V/20A, 8 Outlets with power meter for my 2 circuits 110/120V 20A. With tax + shipping it's CDN$ 491.09.

So I can keep these 2 PDU and then buy 2 more PDU 240V 20A with integrated power meter for my 2 upgraded 220/240V 20A circuits.

I realized though with 220/240V 20A outlet, there’s no PDU with 5-20R outlets so I won’t be able to use the original power cords from my EVGA 1000W Power Supply Units, I’ll have to order IEC C13 to IEC C14 Power Cables - 14AWG.

Damn there’s so much details with the electrical system for GPU mining rigs.

You rock philipma1957!!!

Well living in Canada with cooler temps for the summer may work for you.  But trust me voltage sag is a well known factor all over the world..  While you may spec to 120 you will find you range under and over that 120

Since your mining gear psu's can handle more power I don't worry if you drift upwards to 125 or so it is if you drop to

lets see 115 is

115 x 20 x .8 = 1840 and your rigs pull 1890  do that for 1 hot week you will pop breakers.

 but hey your rigs your home your $$.  Check the voltage with this unit or one like it :


https://www.amazon.com/BALDR-Electricity-Monitor-Consumption-Killawatt/dp/B07Y1SLZ8W/ref=sr_1_1_sspa?

it will tell you your volts if you sag under 115 volts you are in the danger zone.

I am interested in your readings in your home.

you said you have a meter.

see if it shows volts with 1 rig attached
see if it show volts with 2 rigs attached.
see if it shows volts with 3 rigs attached. make the last rig have 4 cards so as to not over load the meter.
see if there is a sag.

if you read 121 then 120 then 118 you may have issues in the summer.

btw the k-watt-meters like my like are not meant to run 24/7/365 with watts over 1200 but you can exceed 1800 for a short time like 20 minutes which would let you see if the line sags under load.

You could be in a very well wired area and not get a lot of sag.

I just checked my volts on my 120 lines they are 121.7
I just checked on my 240 lines they are 243.4

It is cool in NJ ,USA so grid is not stressed I tend to run in this level to the heart of the summer. I will be 117 and 234 this summer.

Thank you so much JayDDee, I really appreciate to have different opinions!
I thought I well prepared my electrical infrastructure but turn out it's much more complicated than I thought.

The CSA standard is for 120V and 240V, It doesn't mean you always get that at the plug. A lower voltage increases
the current for the same power level so it's safer to calculate for 110V.

Thank you philipma1957 for taking the time to explain me all that but I'm confused. My electrician told me that each circuit/outlet is 120 V not 110V. I don't understand why you are referring to 110V, I live in Canada I think it's always 120V or 240V we use no?

I told him that I calculated with the 80% rule that I shouldn't go above 1920 Watts and he told me that I can go up to 2000 Watts no problem. He told me he's been electrician for 31 years  

I verified the wires for each 120V/20A circuit are 12 gauge .

It's good to know I can upgrade but I think I will nevertheless try to plug 3 mining rigs (waiting for the Veddha rack shipped from Hong Kong for the 3rd mining rig) on one 120V/20A if I don't go above 1920 Watts. I will monitor it closely.

it is 110/120

it is 220/240

power sag happens in summer
power sag happens on high loads

so 120 can sag to 110

240 can sag to 220

if you push a line say a 120 volt 20 amp line with 12 gauge wire running 1890 watts.

it will certainly sag in voltage if you run 24/7/365

but your can can handle a sag to 110


if you push a 240 volt  20 amp line with 12 gauge wire you need to get to over 3780 watts to push it hard as the 120 line above.

My home in the winter is around 242 volts in the main box at the 2 hot lines from the street transformer.
MY home in the summer at  3 pm  on a hot day is around 235 volts in the main box at the 2 hot lines from the street transformer.

if I go to the 240 outlets running the gear in my house in winter maybe 239-241 but in the summer 232-233.

these are typical sag numbers for my house.

So if you run your lines 24/7/365 with the loads you speak of you may find you are undersized in July and August.

My suggestion to upgrade 2 of the 4 lines should work very well for you.

This is something I don't understand the 220/240V, in North America it's 240V why 220V? What's the difference? Thank you

Yes 12 gauge is fine for a 20 amp 220/240 circuit.

Since I do not know what he used 12gauge or 10 gauge (bet you he used 12 gauge) 12 is way easier to  use then 10.

My assumptions are 20 x 110 x .8 = 1760 watts in the summer months not 20 x 120 x .80 = 1920

the op said 2 rigs are 1260 so 3 are 1890 and 1890 is just over my assumption that his safe number is 1760.

A lot depends on heat and wire length when you are near the line.

He has zero need to be near the line of overload.

He has spare circuits and upgrading 3 lines to 220/240 will make him be able to run 20 x 220 x .8 = 3520 with the 12 gauge that is most likely in this install .  It allows him to bump rigs to 8 cards so 3 x 8 = 24 cards a ciruit.

if 12 cards were 1260 watts than 24 cards are 2520 watts tack on 80 more 2500 is way under 3520. just better for future expansion.

3 x 3520 = 10560 upgrade to 220/240

and 1 x 1760  for the unchanged 110/120

if he wants to save some coin

upgrade 2 and keep 2

thus

2x3520 upgrade

2x1760 kept the same

total of 10560 watts.

actually this makes better sense  he has plenty of power and it costs less.

 the needs are:

2 more slots in the box.
2 20 amp 220/240 volt breakers
2 20 amp 220/240 receptacles

a good compromise for op.

I agree with everything you said and I'll take your word about the NEC code.
I didn't look anything up but I was concerned about the suggestion that if 10 gauge wiring was installed
a conversion to 220V would be trivial. My point was more about the actual wiring than the code.
But it's moot now if, as you say, 12 gauge can handle a 220V circuit.

Sure it can work for 220v.  More importantly 220v is more efficient in the psu. (go look at the efficienty charts). Thats the reason to go higher voltage.  The wire is rated to 600V.  You can run 20amps of either on it.  It requires diffenent breakers and outlets but the wire is the same. So keeping at 80% of breaker size (standard rule of thumb safety) 120v = 1860watts and 220v = 3840watts...all over the same 12-2 wire and on the appropriate 20a breaker for each. Check the NEC code book.

I see things a little differently.

110V is fine for GPU rigs.  220V would have been better for mining, and necessary for ASIC mining,
but 110 is more compatible with most houshold appliances in North America.

120V/20 Amp circuits likely have 12 gauge wiring, not 10, so converting those circuits to 220V is a no-go.

Three rigs @ 600W each for a total of 1800W is fine for a 20A circuit with a safety margin.
However, that's not an efficient rig design. Two rigs with either more GPUs or bigger GPUs
would be more efficient.

You are not going to be able to safely run 3 rigs at 1920 watts per circuit.

1920/2200 =  87.27%

WTF. where did 2200 come from. 20 x 110 = 2200 and once you have 4 circuits pulling 1920 volts  you will certainly have voltage sag to 107-115 in the hotter months.


So those circuits assuming the wires are 10 gauge and not 12 gauge could maybe do 2400 x .8 = 1920 watts.

MY suggestions are  kick the electrician in the butt as he provided you less than 10kwatts.

you are pretty certain to be able to do 20 x 110 x .80 = 1760 watts if the wires are 10 gauge.

I will rant like mad as electricians are fucking amateurs you are a constant endless hard load on those circuit.

and your guy cut fucking corners.

If I were you I would do 3x 5 card rigs which if you are correct drops you to a safe number.

you said 1260 watts on a meter for 12 cards.  so

10/12 x 1260 = 1050 for 10 cards x 1.5 = 1575 watts for 15 cards.  that will work for you.

Other things you can do tear  his work out on 3 of  the 4 breakers

the 4 th you leave.

the 3 you up grade to 20 amp 220/240 service. you need 3 more breaker slots as each 220/240 line uses 2 break slots.

so you end up with 3 x 2 = 6 slots to run 3x 220/240 breakers

and keep the one he did.

change the sockets to 20 amp 220/240 sockets

so the 220/240 will do

220 x 20 x .80 = 3520 watts that is 5 rigs on each circuit

Nope, just had some issues with my box and house and didn't want to spend a fortune at the time.  I set up the 20 amp circuits 3-4 years ago, before I even started mining

I was referring to 220/240v circuit (which are basically the same)

bretthexum, when you wrote "I did a similar setup and couldn't run 220 for variety of reasons.", are you referring to the new NVIDIA CMP 220HX?

Thanks

I did a similar setup and couldn't run 220 for variety of reasons.

I got a nice 20 amp Tripp Lite PDU from Amazon that shows amps.  80% would be 16 amps.  I never go over that.

I ran the electric a while back before mining, so it's what I got.  Eventually I'd like to get 220 setup somewhere but kind of out of space on the box.

Looper_U do you think I will run into problems if I plug 3 mining rigs (600 Watts each) on a 120V outlet?
I will never plug ASIC on a 120V outlet but for GPUs I thought it's starting small.

Thanks