Bitcoin Forum

I have only one NEMA 6-20 (220v) plug in my garage. I ran only one asic at a time before the halving which was not a problem.

I see there are more efficient machines out from Antminer (like 1700w at 50+ths) Problem is that they require two (2) power cables.

is there any alternative you guys can think of so I can turn one outlet into 2? Or is it not advised since 2 circuits are needed at 10 amp each and my single 6-20 is only 20 amps? (which would not give me enough headroom).

Just trying to think outloud before I commit to a used antminer , cant seem to find them new for now. from what I read buying directly from them is the best route.

If it's really a 20A 220V circuit:

220V * 20A = 4400W

Since you really do not want to go above 70% full time power pull 4400 *.7 = 3080 round down to 3000 for even more of a margin. An S17+ is 2800 so you still have a 7.5% space on top of that in terms of what is good to do.

You can get a PDU to split it to the 2 inputs.

Not recommending this one or even sure it is the correct one, but something like it is what you need: https://www.ebay.com/itm/233486154937

-Dave

To be sure also check the breaker. When I bought my house I found all sorts of outlet ratings (50, 40,30, 20), running on a mix of 20 and 30 amp breakers.

The 2 power cords do not require 2 different circuits (his used to be done by people running S9's on 110V circuits), it's actually just to reduce the load on the power cord and it's connections. Dave gave you the basic breakdown of how to calculate your load and good advice on a PDU. That's a better option than say wiring another plug onto the same circuit.

At the moment my internet is down. Storm knock me out. I would need to see the wall socket  that you have. There are a few ways to hook the gear up. But I need to see your wall socket.

happy to provide a picture of my socket. it was put in by an electrician I hired for rather cheap. i think It is a true 20 amp, as it has 2 20 amp breakers, I assume one for each of the 2 positives.

https://i.ibb.co/m9YsVtN/IMG-20200726-202919.jpg

The PDU seems like the answer to what I need. I googled 220v power strip and obviously got nothing.

You can also look for a power cable splitter - 1 male 6L-20 end with 2 female ends that are C15(?) such as Stayonline has (https://www.stayonline.com/cordbuilder/custom-splitter-cable.asp)

this is what I was thinking originally!  Now I have an alternative to a PDU, though I may go with the PDU for peace of mind/safety.

THANK YOU as always.

thanks for shedding some light on all of this.

Your outlet is a NEMA 6-20.

I'm personally not a huge fan of NEMA 6-15/6-20, and prefer the locking kind... but that's what you've got, so you'll need to match your PDU up to that.

It's more common to find PDUs with L6-20 than 6-20 so you might need to get an adaptor or swap out the plug or outlet (it's pretty easy to swap out an outlet, assuming it was wired up correctly in the first place... turn off the breaker, unscrew it.. move the wires over...).

Just saw the pic. You have a standard outlet box so easiest would be to replace the single NEMA 6-20 with a duplex version like this from McMaster (https://www.mcmaster.com/9096T34/) The outlet cover for it is standard duplex, same as a normal 120v 15A outlet. Home Depot and such should also carry the outlet and cover. Yes it is a dual 20A 250v outlet but that rating is TOTAL amps for either a single cord or 20A split between 2 cords.

As always, current ratings should be de-rated to 80% for sustained loads like miners putting you at 16A total load and on par with what the miner pulls.

Query: Did the miner come with any cords? If so, what kind? That outlet ^ mates with either 6-15 or 6-20 plugs.

Bitmain doesn't ship any power cords with their miners, unlike MicroBt, NFW, according to your experience how safe is it you use screw wire terminal/connectors?

https://www.armacostlighting.com/wp-content/uploads/2013/02/terminal_block.jpg (https://www.armacostlighting.com/wp-content/uploads/2013/02/terminal_block.jpg)

These come with 30Amps ratings, I use them on 99% of my miners and never an issue, I find them a lot more robust than using the regular plug, he would need to take that socket out (while the MCB is disconnected) and then directly wire the power cord to the source wire, of course, this could be against the law/standards in his country, so he needs to confirm that, but here we can do anything because are cool  8) "kidding".

Mikey, it is not recommendable in any way to do it like that. One of your miners start burning and you need to go to the distribution panel and find the right MCB to disconnect it? Hell no.

Thats against the code in many places, Finland at least. And a serious safety hazard.

You need a safety switch if you connect the power cord directly without an outlet: https://www.katko.com/products/enclosed-isolators/

This has been my set-up for years and so far 0 problems, we did this even on a med-sized farm of 300KVA, but I sure won't recommend it if it's against the standards in someone else's coutry.


That makes sense, but many farms are not guarded 24/7, so there is always a chance that one miner will catch fire and it makes no difference if it's plugged this way or another, so I just have to make sure that no miner gets set on fire, also if something serious like this happens and I happen to be around I would simply disconnect the main breaker, the distance between the breaker and the socket "if there was any" is only a couple meters anyway.


Ya, I figured that much out, that's why I asked, thanks for letting me know.


HagssFin, how does this differ from the regular main 3/4 pole breaker like this one? https://breakeroutlet.com/circuit-breakers/abb-s5h-sace-s5-400-a-circuit-breaker/

They differ in their design purpose. A MCB (Molded Case Breaker) is NOT designed to be used as a switch. They are purpose designed strictly for overload protection and to be used for occasionally manually interrupting power for maint/service operations.

btw: yes there are breakers designed to be installed into lighting power distribution/switching panels but they are purpose-designed for frequent switching and are identified & sold as such.

Power disconnect switches, fused or un-fused, are just that - power switches - and are designed for frequent usage as a main disconnect to switch power to equipment on & off. Also most will have provision for LOTO (Lock Out, Tag Out).

When it comes to 'on the fly' splitting of wires I love the WAGO 'Lever-Nuts" (https://www.amazon.com/gp/product/B07CJR8MH4/) that Haggs mentioned a long while ago. They beat the hell outta the twist-on nuts I used to use and are available in 2,3,4,5 and I think 6 wires per block.

I would never use those nylon terminal strips for power distribution - too flimsy and too little material in them to hold up when things go bad. Think of what happens to nylon PCIe connectors when they get burnt - not pretty... Use real barrier strips or terminal blocks that will much better withstand overloads and poor connections.

Because we has a tropical storm roll through here a few days ago and I have been doing cleanup work on replacing blown PCs and stuff since then.

If you have the $ you might want to invest in a UPS big enough to handle the miner. Not cheap but you might just save your miner, or your next miner, or the one after that.
Yeah, used with batts you are probably looking at close to $1k. But you can skip getting the PDU.

Not really affordable if you have a large farm, but for one circuit it you might want to think about it. Don't know where you are so if you don't have issues like coastal storms and the such it becomes less of an issue. If you are in coastal Florida you might want one.

-Dave

I got a few high quality power conditioners that could work for him.

I will look for ebay link.

sold out on ebay I got mine for 200 they are great to run 1 s17 pro

this company wants to much  $$$
http://www.tynex.com/item.asp?PID=37538&CID=1236&menutype=P

these are great for 200 bucks. I grabbed 4 of them last year.  which is less then the guy wants for 1 .

let me look to see if I can find some.

https://smartpowersystems.com/wp-content/uploads/2020/04/AVRPlus-UG.pdf

they really run voltage tightly

https://smartpowersystems.com/automatic-voltage-regulators/