# Mining operations and SAFETY?



## Carsomyr (Apr 6, 2021)

1. Is using a pcie extension riser cable safe for mining?
2. Which kind is safest? 
3. How many GPUs could an asrock Z390 phantom gaming handle (for mining) 
4. How many WATTS or GPUs must one have in a rig before needing MODIFICATIONS to your room or house? (220v outlets etc) 
5. Are there other precautions I must take to avoid fire hazards or damage to my house?


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## qubit (Apr 6, 2021)

Depending on how many graphics cards you use, the standard mains socket won't cut it as you'll overload it. So, you must factor your house wiring into the equation and your electricity bill. Not an obvious or easy thing to sort out at all, I'm afraid. Actually making a profit from a mining rig is a very delicate balancing act.

I'd Google for info on this and see what comes up. Don't just wait for replies here.


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## Chrispy_ (Apr 6, 2021)

I'd like to know what domestic UK wiring code allows.

My two mining rigs suck down about a KW each, and I plug each of them into a double wall socket. I've never thought twice about it as my electric kettle is 2.5KW and it's not even a rapid-boil modle. If I'm ironing the laundry as I boil the kettle, that's over 4KW being drawn from the same outlet in the kitchen. Why would I worry about a couple of KW from two mining rigs.

With the ETH prices being so good lately, I'm considering scaling up, and wondering just how much I can push the house wiring.


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## dgianstefani (Apr 6, 2021)

Only power the risers with molex. Sata is only rated for 50w and pcie socket can pull 75w.


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## qubit (Apr 6, 2021)

Chrispy_ said:


> I'd like to know what domestic UK wiring code allows.
> 
> My two mining rigs suck down about a KW each, and I plug each of them into a double wall socket. I've never thought twice about it as my electric kettle is 2.5KW and it's not even a rapid-boil modle. If I'm ironing the laundry as I boil the kettle, that's over 4KW being drawn from the same outlet in the kitchen. Why would I worry about a couple of KW from two mining rigs.
> 
> With the ETH prices being so good lately, I'm considering scaling up, and wondering just how much I can push the house wiring.


Sounds like you could be in line for a potential house fire, or at least trip the circuit breaker.

The typical UK ring main is designed to deliver 30A. However, if you can really pull this much safely depends on the age and condition of your wiring.

Bottom line, is that it’s not wise to advise others to draw so much current without even thinking about it.


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## P4-630 (Apr 6, 2021)

Mining operations and SAFETY?​




__





						Standards and Regulations | Mine Safety and Health Administration (MSHA)
					

The Code of Federal Regulations (CFR) is published and updated annually by the Office of the Federal Register. MSHA rules are in Title 30 of the CFR, Mineral Resources, Chapter I.




					www.msha.gov


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## Chrispy_ (Apr 6, 2021)

qubit said:


> Sounds like you could be in line for a potential house fire, or at least trip the circuit breaker.
> 
> The typical UK ring main is designed to deliver 30A. However, if you can really pull this much safely depends on the age and condition of your wiring.
> 
> Bottom line, is that it’s not wise to advise others to draw so much current without even thinking about it.


That's why I'm asking. If your wiring isn't up to code, then all bets are off; With wiring faults, plugging in a 5W phone charger could cause a fire - let's not get into the symantics of something I didn't ask.

I asked for domestic wiring code. If that means that UK domestic circuits are supposed to handle 30A, then that's good news. 2KW is only 9A at 230V AC

As for suggesting I haven't even thought about it - that's a little unfair. I clearly gave you the single most common domestic appliance in the UK and told you that it draws 2.5KW. Why would a PC that draws less than a kettle be a problem? Realistically when preparing food it's not unreasonable to expect a kettle, toaster, and microwave oven to all be operating off the same circuit at once - drawing somewhere in the ballpark of 5KW. This happens daily in millions of houses.


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## qubit (Apr 6, 2021)

Chrispy_ said:


> That's why I'm asking. If your wiring isn't up to code, then all bets are off; With wiring faults, plugging in a 5W phone charger could cause a fire - let's not get into the symantics of something I didn't ask.
> 
> I asked for domestic wiring code. If that means that UK domestic circuits are supposed to handle 30A, then that's good news. 2KW is only 9A at 230V AC
> 
> As for suggesting I haven't even thought about it - that's a little unfair. I clearly gave you the single most common domestic appliance in the UK and told you that it draws 2.5KW. Why would a PC that draws less than a kettle be a problem? Realistically when preparing food it's not unreasonable to expect a kettle, toaster, and microwave oven to all be operating off the same circuit at once - drawing somewhere in the ballpark of 5KW. This happens daily in millions of houses.


I wasn't answering a question, but responding to your statement.

You say that you draw 4KW from the same outlet in the kitchen. I presume that's a double socket? Technically, that's not an overload for the ring main, but it's rather high, especially when taken from the double socket, rather than two sockets far apart. The plugs will get physically hot at that power draw and that's the main problem. 1KW will cause heat from one socket, let alone 2KW and the socket and wiring will degrade over time with that kind of stress.

Thing is, stuff like that can indeed cause a fire without ever tripping the circuit breaker, since the current is never high enough, as the connection degrades, increases resistance, degrades some more and so on until it enters a heat spiral and potentially catches fire.

I suggest you put your hand on those plugs after the equipment has been running for a while and you'll see that they'll be rather warm. That's not a good place to be for safety, especially.

Look, don't take it from me. Put your scenario to a qualified electrician and see what he says. There are electrician forums around the web where you could get an authoritative answer to this question.


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## Chrispy_ (Apr 6, 2021)

Hmm interesting.

I posed a question to the electrician at work, he said that houses built to code in the last 35 years with RCD breakers are absolutely fine for sustained loads as long as you stick to the limits - 13A for a single socket and 20A for a double socket. The 2.5mm wire that connects each socket to the breaker box is good for 26A before dangerous heating occurs, and of course that value has a safety margin built in to assume the worst-case scenario of an old cable stuffed into dense insulating foam with zero ventilation to cool it. The reality is that interior walls are usually open ventilated spaces.

Anyway, a 32A breaker doesn't trip instantly when 33A are applied - it uses resistive solder that melts over time. The higher the current the faster it will melt but it could take several minutes to trip at 33A and fast trips that occur within a second or two are usually hundreds of amps associated with a short circuit. The reason 32A breakers are used for domestic circuits is because the 2.5mm wire used is rated for 36A indefinitely and 46A for at least an hour. That means that you should never run into dangerous wiring/socket temperatures if you stick to the 13A single, 20A double socket current limits. You'll trip the breaker before any wiring gets too hot and 20A from a double socket is 4.8KW _from the wall._ Even with a couple of 2KW PSUs per rig, a double wall socket is still overkill in a good way.

As always, don't run multiple high-current devices off a single plug. That 6-way power bar is not going to handle three mining rigs


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## Carsomyr (Apr 7, 2021)

Chrispy_ said:


> Hmm interesting.
> 
> I posed a question to the electrician at work, he said that houses built to code in the last 35 years with RCD breakers are absolutely fine for sustained loads as long as you stick to the limits - 13A for a single socket and 20A for a double socket. The 2.5mm wire that connects each socket to the breaker box is good for 26A before dangerous heating occurs, and of course that value has a safety margin built in to assume the worst-case scenario of an old cable stuffed into dense insulating foam with zero ventilation to cool it. The reality is that interior walls are usually open ventilated spaces.
> 
> ...


Thank you very much


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## qubit (Apr 7, 2021)

Chrispy_ said:


> Hmm interesting.
> 
> I posed a question to the electrician at work, he said that houses built to code in the last 35 years with RCD breakers are absolutely fine for sustained loads as long as you stick to the limits - *13A for a single socket and 20A for a double socket.* The 2.5mm wire that connects each socket to the breaker box is good for 26A before dangerous heating occurs, and of course that value has a safety margin built in to assume the worst-case scenario of an old cable stuffed into dense insulating foam with zero ventilation to cool it. The reality is that interior walls are usually open ventilated spaces.
> 
> ...


Very interesting info, especially the bit in bold. At first glance, you'd think it would 13A and 26A, but no it's actually only 20A. I reckon the main reason for this is heat, as more current could lead to thermal runaway.

Also, modern RCD breakers don't use a soldered fuse since they can just be reset by pushing a switch back to its original position, but some other way of sensing overcurrent (I'm guessing some electronic means) and react much faster, so are safer should an overload occur, even a "mild" one of the 33A or so variety.


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## Chrispy_ (Apr 7, 2021)

qubit said:


> Very interesting info, especially the bit in bold. At first glance, you'd think it would 13A and 26A, but no it's actually only 20A. I reckon the main reason for this is heat, as more current could lead to thermal runaway.
> 
> Also, modern RCD breakers don't use a soldered fuse since they can just be reset by pushing a switch back to its original position, but some other way of sensing overcurrent (I'm guessing some electronic means) and react much faster, so are safer should an overload occur, even a "mild" one of the 33A or so variety.


Yeah, 20A for a double is because although each socket in a double can handle 13A, the copper bus bars that feed the two sockets don't necessarily handle 26A. The BS1363 standard tests at 14A+6A for a 48H period.

As for RCDs, you made me do some more learning - Most of them are dual-action:

There's a solenoid that _instantly_ trips the spring trigger if the current through the solenoid overcomes the spring tension. This is made to trigger at 3-5x the rated current of the RCD. This will stop the sort of currents that will kill you.
There's a bimetalic strip that slowly unhocks the latch of the spring trigger if too much current warms it up. This is made to trigger at about 1.3-1.5x the rated current of the RCD. This will stop the sort of currents that slowly heat up your house wiring to dangerous temperatures.
Interesting too, then, that the 32A breaker won't trip until at least a sustained ~41A load. I guess that's why house wiring must be rated to handle 46A for an hour, because that's the worst-case scenario for a 32A RCD breaker, plus a margin of tolerance/safety.

The goal of the spring trigger is to minimise arcing. Whether the RCD trips due to solenoid or bimetalic strip, the end result is a rapid snap opening of the circuit. After all, a short or ground fault could draw hundreds of amps and create an arc circuit inside the RCD. The snap, as well as ceramic-insulated arc-splitter plates means that arcs of hundreds of amps have been considered in the design and accounted for.

I certainly feel a lot more confident in my house wiring now. I'm not pulling more than 9A from any double socket rated at 20A, and even if my house was wired badly by someone ignoring code and connecting a spur to a spur to a spur, the "36A indefinitely" rating on the wire means that it shouldn't be a problem even if four double sockets are daisy chained in a very illegal and very stupid way.


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## sepheronx (Apr 7, 2021)

Here, we are 110/120v outlets.  I just ran a separate line to a new breaker.  15A so that gives me roughly 1800W to work with minus 20% (since we are told to never exceed 80% usage). 

I am not entirely sure the code in the UK, but I assume its about the same.  Only difference is that since you are on a 220V, multiply that by 13A (if the breaker is that), then that gives you 2860W of total power from that line.  Now multiply that by .8 and that gives you 2,288W to work with in an outlet.


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## trog100 (Apr 7, 2021)

my 7 card mining rig six 3070 cards and one 3080 card draws about 1k from the wall.. i think some folks think gpu mining draws a lot more power than it really does.. 

i am in the UK and could run to of them from one 13 amp socket with plenty to spare.. 

trog


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## Chrispy_ (Apr 7, 2021)

sepheronx said:


> Here, we are 110/120v outlets.  I just ran a separate line to a new breaker.  15A so that gives me roughly 1800W to work with minus 20% (since we are told to never exceed 80% usage).
> 
> I am not entirely sure the code in the UK, but I assume its about the same.  Only difference is that since you are on a 220V, multiply that by 13A (if the breaker is that), then that gives you 2860W of total power from that line.  Now multiply that by .8 and that gives you 2,288W to work with in an outlet.


Having just looked up British Standards 15 minutes ago, I believe the 80% safety standard is built-in; 

The BS1363 code requires that a single 13A socket must be able to handle a sustained 3KW load, which is 13A exactly at 230V. I guess that's why we get 2.5KW electric kettles and 3KW plug-in heaters over here, they'd just trip a US circuit breaker immediately!


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## sepheronx (Apr 7, 2021)

Chrispy_ said:


> Having just looked up British Standards 15 minutes ago, I believe the 80% safety standard is built-in;
> 
> The BS1363 code requires that a single 13A socket must be able to handle a sustained 3KW load, which is 13A exactly at 230V. I guess that's why we get 2.5KW electric kettles and 3KW plug-in heaters over here, they'd just trip a US circuit breaker immediately!


Gee, that makes things easier for you guys. Half the time I'm running around, plugging in my wattage meter and doing calculations to make sure I'm not hitting the 80%.  Also reason why I have been running multiple lines. I'm no electrician but I might as well be one now.


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## qubit (Apr 8, 2021)

sepheronx said:


> Gee, that makes things easier for you guys. Half the time I'm running around, plugging in my wattage meter and doing calculations to make sure I'm not hitting the 80%.  Also reason why I have been running multiple lines. I'm no electrician but I might as well be one now.


Did you know that the mains power to the home in the US is actually 240v in a split phase arrangement? Yup, that’s why there are 3 wires there. The neutral transformer centre tap and the two hot wires.

Between any hot wire and the centre tap is 120v and between the two hot wires is 240v. This can lead to dangerous fault conditions where if the centre tap fails, you can suddenly get 240v across an appliance, which promptly goes bang.

I saw this demonstrated with a low voltage demo and a couple of lamps, in a YouTube video. Fascinating.


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## sepheronx (Apr 8, 2021)

qubit said:


> Did you know that the mains power to the home in the US is actually 240v in a split phase arrangement? Yup, that’s why there are 3 wires there. The neutral transformer centre tap and the two hot wires.
> 
> Between any hot wire and the centre tap is 120v and between the two hot wires is 240v. This can lead to dangerous fault conditions where if the centre tap fails, you can suddenly get 240v across an appliance, which promptly goes bang.
> 
> I saw this demonstrated with a low voltage demo and a couple of lamps, in a YouTube video. Fascinating.


yeah, but that is why our electrical box is as basic as basic gets - to prevent idiots like myself from causing real damage.  Essentially, if I need to put a 240v line in, I need a very specific breaker (and get the corresponding gauge cabling).  I would rip off my electrical panel to show you guys but....that actually requires work and I am lazy.  It is more or less just a larger breaker of the same design that is roughly 40A or so.



			https://www.hunker.com/12280994/how-to-install-a-240v-circuit-breaker
		


What I hate, is how every company has to be specific about how their breakers work.  I have a GE (Garbage Electric) breaker panel and I had used a Siemens UL breaker in it before (since it is supposed to work and works perfectly fine now).  But they changed the Siemens UL breakers now so that they purposely cannot fit inside.  Now I am stuck finding only GE brand breakers and for being a generic company, their breakers are much harder to find here.

Anyway, this is off topic.  Sorry.


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