Topic: Farm on fire 2.0 (Read 409 times)

I hope now the OP has calculated the load correctly and it will no longer lead to such sad consequences, the attitude of users who use cheap peripherals to power expensive equipment with a high load and even 24/7 is always surprising.

yeah we take no chances.  every 3000 watt plus miner is on a dedicated 30amp l6-30r socket.

better safe than sorry.

these 3000 watt plus units pull heavy power. and we know our 240 volts sometimes drops to 190 volts the 30 amp circuits cover us when this happens.

Ya fake products make things a lot worse, but then even the original wall sockets can't do with mining for the most part, at least not where I live, the standard wall socket is rated at 15amps, so at 220v they are maxed at 3.3kw, all the new miners are either just about that or slightly below, so even the original ones will eventually fail and burn given that they don't get to cool down as mining runs 24/7.

The next issue would be the wire size that connects to that socket, the standard here is 2.5mm copper wire for wall sockets, which should easily handle 20-30A if it's just a hairdryer and say your hair is pretty long and needs an hour of drying, but then going past that you might run into issues, so even if you replace that socket with a 20A socket the wire won't be able to handle it and the results will be the same.

I don't know about the U.S and other countries, but here, it's completely unsafe to run something like a Whatsminer m21s that sucks nearly 3500w 24/7 on any residual socket.

Sigh, this is a wrong wiring at its best, I nearly burnt down my home too months ago because I use a bad built socket that pretended to be original, I held the seller responsible because he sold the extension socket to me telling me its original but we later work things out, when it comes to mining never cheap out on anything, we are playing with electricity here, its the last thing you want to F word with.

They could probably do, but I don't use them on miners directly, I have 400a 3P contactors, each hold 5*80A 3P MCB, I just connect the Sonoff to the contactor so I can control the 5 MCBs with a single smart switch.

Also since the direction of wind is pretty funny where the farm is, also temps changes a lot during the day, I use these smart switches to control the wall fans, so I connect the fan wires directly, but I don't think any set of fans I have go past 10A so the smart switches are not being stressed at all.

While these are cheap, I don't think buying 1 for every individual miner makes economical sense, it would be better to just buy a smart PDU, a smart PDU that can power 24 S19s will be priced at below 1K at most, somewhere near double the price of the basic version, so we can say that all you to pay is 20$ more per miner if you wanted smart vs basic PDU, despite the fact that the smart switch is cheaper than 20$, the smart PDU beats it in terms of safety, installation and a few other things.

Now if you have just 2 miners, then ya 500/2 = $250 more per miner, so I'd stick with the smart switch.

That's quite smart. I just checked Sonoff website, it seems like they have a pretty cheap 16 amps "Smart Switch" https://sonoff.tech/product/diy-smart-switch/minir3/ , which should be fine with Antminer S19 86TH (consuming only 3 kWh)? It will be loaded at ~86% though...



That's very interesting, I think many in the mining industry, including myself, never thought much about the long term effects of dirt on the active contacts. Thanks for sharing 

Something that was told to me that I don't follow, and it was long before BTC / miners existed but.....

Not sure how true it is, but years ago I was told NEVER touch the prongs of plugs with your bare fingers unless your hands are clean.

Been working, moving equipemnt, touching some dirty things. You then touch the prongs and transfer some of the oil (not a big deal) and dirt (big deal) to them.

On 99.999% of things it does not matter. High power, for long term without being plugged and unplugged which would scrape off the crud you stand the chance of adding resistance.

As the person who explained it to me said, even though the chances are small it has been procedure in certain industries for years, and nobody would come up with something so silly if something bad had not happened.

-Dave

The one I bought was basic PDU, but they do have smart pdus, however, they are not as big as the basic one, they are rated at 125a max, with 3.4kw max on each port at 220v, it could still run most miners but not with much room.

However, they told me I can send my own design and specs and they will make the PDUs accordingly, but I think that will require some MOQ.

Also smart PDUs usually cost a lot, it is cheaper to just install some contactors and control them with smart wifi devices like Sonoff, that will also allow you to install voltage protection, phase sequence and other types of controls.
 

That's nice, especially if they are remotely controlled.

It's common sense that If you can't afford proper PDUs simply cut the cable ends and use a wire-end on a busbar that can take the load, even if that goes against your local code -- it is a million times safer than using those power strips, if you check the wiring and connections inside them, you will notice that they can hardly run anything, mostly 1mm2 wires soldered in the cheapest possible way.

Furthermore, it's not only about the wire size, I had some power strips that used fairly large wirings inside that could easily handle a couple of miners, but then socket martial was pretty bad, and the plug was a little lose, I have a general rule that if I can unplug something without worrying about the whole socket coming out, that thing will likely catch fire. So if you can easily plug and unplug the power cord -- there is probably something wrong, electricity does not like "loose", like most of the men electricity likes "tight".

Anyway, I found a great source of PDUs in China, the manufacture for some US vendors under a different brand, I ordered a 3P 160A PDU from them which should be here soon, it has 24 ports, and each port should easily handle 4.4KW at 220v, that means it can easily handle 24 of most miners out there, I will be posting pictures and stuff when we set it up.

As a connection gets warm it will oxidize. Resistors are made out of metal oxides. As power continues to flow through the resistive material it only gets hotter and eventually compass or melts the receptacle. Heavy duty receptacles have greater holding force, more points of contact and higher temperature plastics/ceramics. A stronger holding force can reduce the amount of oxygen reaching the junction mitigating one factor. More points of contact distributes the flow over wider surface reducing the initial temperature increase. And the other factor just allows the receptacle to function much longer through the degradation. There is one Super cheap option that might just allow you to continue without upgrades, dielectric grease. The only purpose of dielectric grease is the cover surfaces and prevent oxygen interaction and oxide formation.
J

Its a good thing that it didn't turn out into an uncontrollable situation that renders all your equipment and even the structure where you house your equipment bad. It is a lesson learnt and a lesson to everyone to always seek professional assistance from people when it comes to anything that has to do with electricity or electrical wirings. If that had been what you did, this situation would have been avoided because they would have brought to your notice on time that those cheap outlets are not suitable and cannot handle the load and high temperatures from your equipment.

The stuff that was used here was mostly consumer grade, electricians waned about the outlets not capable to withstand high loads, but somehow their warnings were ignored  . Same applies to the power wires, they get heated a lot, but it's expensive to have thicker ones. Anyways, it's all part of the history now, lessons learned 
Best advise to anyone mining is to keep fire extinguisher nearby. The one that was used during this accident is dry powder based, it works just fine, no need for the expensive stuff. After a cleanup with isopropyl alcohol miners are in the working condition again.

 Yeah lightning can do magic when it comes to killing gear.

My home is grounded for lightning.
My cable is grounded for lightning.
I have a whole house surge protector.
I have my main circuit breaker grounded in two spots.

I have all kinds of extra surge protection.

Here comes the magic of ligtning.

I had a $1000 dollar good quality marantz home theater avr.

a lighting bolt hit very nearby july 2021.

one thing broke in the entire home.

the hdmi input on the marantz.

out of warranty by a few months so oh well.

so I grabbed a good quality denon avr last july 2021

about 900.

this august a nearby lightning strike and guess what broke

the hdmi input on the denon.

now i did research marantz and denon are related companies .

they are known to have some hdmi board issues.

but whether the surge entered in the power lines or the cable line I do not know.

I will be looking to add more filters to my system.

as breaking 1000 dollar avr’s every 13 months is not acceptable.

The avr has a tv connection that could have sent the hdmi surge
the avr has a dvd connection that could have sent the hdmi surge
the avr has a pc connection that could have sent the hdmi surge
the avr has a cable connection that could have sent the hdmi surge.

all units still work fine  other than the avr.

lastly it is 32 days since denon repair has the avr I am due a replacement from denon.

no hdmi boards available so I get a new unit.

point is even with thousands in protection gear breaks.

It's not just without knowing what you are doing. It's not using industrial rated equipment, I had this happen to me early this year.

https://bitcointalksearch.org/topic/its-not-just-power-supplies-its-the-cables-the-pdus-protect-everything-5383773

I'm sure there are 1000s and 1000s of people with 1000s of stories that we never see or hear about when something that was "good enough' went poof and destroyed a miner or 2.
They might not even know what caused the issue, they just moved on.

-Dave

Again it must be said: When building mining platforms one MUST follow local industrial wiring codes for distributing the power. If local codes are non-existent then follow international ones.. The pics above are just more proof of what WILL happen when ya 'just run a lot of wires' without knowing what you are doing...

I've had power strips die on me for no apparent reason, and there wasn't even a miner attached to them, just normal devices.

But one of the signs of a cheap mode is in its LED, if you look closely at it and parts of the red light are subtly flickering on and off. I'd stay away from those for mining.

what a mess! but did you use normal power strips? they are not the best for asics .. they support 2500w at most those.

Cheap power outlets are causing problems. Confirmed this summer 




High loads combined with the high temperatures caused some irreversible damages.



The fire spread from the board where the outlets were assembled.



Some machines burned.





And some power wires as well.





Here is a short video overview: https://imgur.com/Kte0KG2

The good thing is - those were the old S9 models.
Lesson learned - no more outlets.
The new setup with S19 machines looks much better without them.



When this farm was established, we marked BTC price on the newly laid concrete floor - it was around $8.6k, which is a reminder that there is always light at the end of the tunnel and we shall make it through the hard times again.