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Hi All - I have an Avalon A741, T9, and 2x APW3+ 1600w on the way. i'm looking for ~5 min of failover support (enough time to rush over and turn them off normally) and some decent current filtration, even though the brownouts are infrequent and slight, i'm going for longevity. Is it better to have 1x UPS for each or OK to have one big UPS for both? I think i'd rather go with something like APC instead of the cheaper appearing brands?

Thanks!

thanks!
so is it still the same 75-80% load rule ~1600/.8=2000w per?
also are there specific APC units that boast better filtration vs failover support time?
some of them don't appear to mention current filtration..

First of all, be aware that most UPS's are what is known as 'off-line' types. What that means is that when your power drops below the trip point the is several ms of time before the UPS kicks in. If the UPS has voltage control, that too is relay switched and will have the same transfer time.

Check what that transfer time is! Since most PSU's will hold up and continue to provide DC for 10ms (at-best) the transfer time MUST be less than that. Even then the miners still might not like it. Mine first ones even back in s1 days didn't :(

What I use are called 'on-line' UPS's from Cyberpower, specifically these https://www.cyberpowersystems.com/product/ups/ol3000rtxl2uhv/
On-line UPS's are well, always on. They continualy take the AC line, change it to DC voltage close to what the battery pack provides, and then use that DC to power the output stage all the time. The output is a near-perfect AC sinusoidal waveform and on-the fly adjusted to whatever voltage you set it to.

Even better, if ran at 1/2 load it will still provide perfect power even down to 50% AC nominal in without going to battery.

I have 2 for the 2x s9's in my basement and love 'em. Pricey but you can find better pricing if you search online.

edit: also must add those are ONLY at my home where voltage will occasionally sag from the normal 230ish VAC to as low as 180VAC during summer. My main farm (32kw) is at work with excellent power service so only 1 UPS there and that powers just the network equipment.

thanks FW!  :D

ya that appears to be slightly overkill for my situation lol, although an incredible unit..
i need to find a way to exactly measure the 'sag' in my home voltage before going any further, what is the easiest way?

also, what do you consider 'excellent power service', a variance of what %/sag?

greatly appreciate the info given in this thread and others!

edit: something like this to measure sag? i can look over throughout the day and then see how much voltage regulation i need with a UPS?
http://www.ebay.com/itm/Blue-LCD-Digital-Voltage-Volt-Meter-AC-110-300V-US-Style-Plug-110V-220V-/271102731277

For one, get a digital voltmeter. Even a cheap one from a hardware store or whatever will be fine. From measuring the AC line to what voltage a PSU is providing, a meter is a must have.

As for recording sag not sure. I used to just check the AC line during very hot days. Now just consult what the UPS's report ;)

Excellent is never dropping more than 5% below nominal. The line going high is rarely an issue for most equipment.

We are in an industrial park at work and have 500KW 480v heavy power so it is pretty damn good. After step-down to 208v for areas that use it like the offices, without dropping a phase completely I think the lowest my monitoring gear there has even seen is 201v - about 1% drop. Also have 75KW backup generator there fed from the natural gas line to keep the front-office, heating/cooling and my miners alive.... ;)

thanks! thanks!!

Buying a UPS will add to the amount of money you need to spend on your mining equipment, and they only have a limited life, even if the power does not go out. With margins on mining being razor thin, it may not always make economic sense to invest in UPS's to use in conjunction with mining -- I would opine that you probably should not connect your miners to a UPS.

On the whole I have to agree.

Yes most of the UPS's you find will in 1-2 years start beeping about needing battery replacement. Top-end ones made for use in critical ares such as data-centers and network racks like the Cyberpower Smart-App one I linked to do far better. My oldest is 3 years old and yes, reports a drop in life but the extremely heavy yet easily replaceable battery pack still has 90% capacity due to intelligent battery control. So, you get what you pay for.

If you only care about voltage regulation - and don't care about taking about a 5-10% efficiency hit - then look at constant voltage transformers like those found here about 1/4 the way down the page https://www.mcmaster.com/#ac-to-ac-power-distribution-transformers/=17dcwa9

Yes, pricey but work very very well, are nearly bullet-proof and, are zero-maintenance. I know of some customers that have ones in use for decades. Again, look around online and ya might find better pricing. Weigh a lot so shipping probably not included...

edit:
Yes, that would be perfect.
Me likey :)

agreed as well
however

i think it completely depends on the scenario, if sags are small enough and infrequent enough, accompanied with little to zero power outages per year, it seems like a UPS doesn't provide much benefit.
i will have to rig up a digital voltmeter (on the circuit the miners are planned to go on) with a timelapse camera or something to see exactly what kind of behavior i'm dealing with.. admittedly, power outages are very rare around here and so are 'dimmed lights'..
@NFW - if your home voltage didnt sag as much as it did, and was more similar to the stability of your workplace, would you still use 2x UPS for the S9s?

No I would not use them. If power is good and you have properly sized server PSU's then be happy.
Also see^^ about the meter. Nice.

 This the dumbest shit I ever heard. If power flinches.. sobeit! Your actual loss vs. buying high dollar UPS is insane if not stupid to ask! I mean no offense man, but 2 fucking s9's in the grand scheme are jack shit!

 Buy 1 good UPS for your main pc that runs your wallet. That is better advice I promise.

Scrapp' out

Riiiight.....
It all depends on ones situation.

I got the 1st Cyberpower UPS in 2014 originally to power my Ant s1/3's. It 'cost' me nothing as they were paid for in BTC from farm income. At the time was running 6 miners at home and that was about 1/2 my hash power. Considering I travel a LOT having the backup was pretty necessary since I could not get to the miners sometimes for weeks. The 2nd UPS was bought after the s5's came out and again just for the home farm.

UPSs are definitely worth it, just make sure you're getting the UPS from a reliable brand like APC. I've had great experiences from their UPSs and I even use it to run a home server. Server hasn't gone offline in a year with a single APC UPS.

UPS are a giant waste of money. I dont even understand the thought process.

I have to know....what exactly do you think is a 'normal' shutdown that requires a UPS?

The proper way to shut down a miner is simply to remove power. A power outage does this for you. Thats it, theres nothing else to do. They run read only firmware so its not like you can damage anything by just randomly losing power. Also...the PSUs are internally regulated, you shouldnt have to worry about power fluctuation at all.

 a smaller ups  for the router is okay.  I have one ups  it covers my router  my gigabyte  switches and 1 pc.  not a single miner is covered.




@ op
where are you living  that power fluxes up and down so bad it hurts your psu's

On the whole you are right -- with Bitmain and other stand-alone miners, PSU's drop out and everything including the controller shut off. With Avalon's, up to you how you power the RiPi but do realize that the 5v supply to the RiPi will probably hold up longer than the hash board power does. So far seems twitchy with my Avalon's on recovering from a power blip but a full hard boot fixes that.

Where possible problems can happen is when the power comes back on. Rarely is it a clean on-again, the voltage WILL briefly bounce around - IF the controller happens to be writing to a flash memory address or SD card and the process is munged by a couple false-restarts, that is when memory corruption can happen. The old s2 was a prime example of that. In the case of the Bitmains it is not the ROM segments that can be affected - it is the flash memory holding user settings and whatever Auto-tune comes up with. Knowing Bitmain I doubt they properly implemented any kind of power-fail-stop-writing logic. Ideally the IP-Reporter reset button trick *should* reinitialize/format the flash subsystem.

Do take note of the 'if' and 'can' -- unlikely to happen but cannot be dismissed. Is probably the reason that Bitmain always states something along the lines of waiting several min or (much) more after updating before you do a reboot.

All that said, again, I have a reason for the 2x 3KVA UPS's I use at home. For most folks, not needed. Then again I also have a permanent genset tied to the gas line for whole-house backup. UPS's handle the brief time between power and generator kicking in and xfr time when power comes back on so it's non-stop mining for me at home :P

I have managed over 6-8000 Avalon6's in my time and never had an issue that required a UPS. Maybe the 7 series act different? I have had plenty of SD cards corrupt themselves in that time but that is just normal behavior with old RPi's and a hacked together OS. The fix for that is to just have a spare on hand if you dont want to take 3 minutes to reflash the SD card when that happens. Ill take the $4 fix over the hundreds of dollars a UPS would cost.

It could still possibly cost you a few hours of hashing as not everybody is home all of the time when something goes wrong. It's not required but it's also a small hassle when it does happen. I just happen to use UPSes because I have em from servers and they help keep miners up for practically nothing in my scenario.

For the Avalons, ja. Not so easy with the Bitmain products. Still as I keep saying, for most operations UPS is overkill. In my case the reason for the always on-line UPS's at home was sag. Some summer days the nominal 230v went as low as 180v and of course the generator does not kick in until it goes below 178v. Can't adjust the trip point so got the Cyberpowers. They will supply the miners perfect 240v even with the line below 160v so no-mans-land dead-zone is covered.

Sidenote to that: Got the whole-house generator after the 2-week long blackout that hit Michigan, Ohio, and part of Ontario several years ago. Up until 2 years ago when a huge storm literally blew out the local substation and grid it was needed several times a year. After those repairs, power has been much better, last year worst sag was only down to 208 so very happy with the new grid lines they installed everywhere and outages have been rare :)

If is a mega-farm then my plan would be to have backup genset(s) yes but manually control changeover.
eg.
Power drops out, let miners go offline and remain powered down(network gear IS of course on a UPS).
Start generator if not automatic.
Contact power company.
If after a few min still no power - change over to generator
Start miners

When stable power returns:
shut down miners
Change over to Utility power
restart miners
Kill genset

Whole point there of course is to minimize how many times all those $&^#! miners of yours need to be restarted.

Exactly. Besides, when I got them I was making BTC hand over fist and since the now-defunct TigerDirect accepted BTC, well, was just the thing to do.

Now 1st place I look is Overstock.com 'cause they take BTC :)

I found brand new EATON 9130i Rack Mount 2000 VA 1800 Watt UPSs with 2 yr warranty on eBay for $400. Can't beat that.

So you can put one miner on a UPS. You have also increased its ROI time by 3 months. Thats like 1700 hours of hashing to pay for the UPS that will in its lifetime prevent maybe 6 hours of downtime?

I am so not understanding where you people think this is a good idea? Its like you are looking for ways not to ROI

Well maybe they have terrible power quality.

Here in NJ  they rebuilt a lot after Hurricane Sandy  so I  get 121-122 at mains  and 243 for 240 power.

All my wiring was done by me other then the main box.

My home was built during Vietnam war.  USA was short copper and I had all aluminum wires.  Many 1966-1973 built homes in

NJ  were done with aluminum.  I replaced 100% of the wires in the 90's Well before BTC  came around.

A homeowner in NJ can do their own wiring if they continue to live in the home.

Since I was saving a lot of money DIY  I did every upgrade with better guage wires.

So all my 12 gauge 15 amp circuits are 10 guage 20 amp circuits
I get very little power drop.
I put in a whole house surge protector.

I consider those upgrades to be far better to do then to buy lots of UPS gear.

We can go 6 months with no power failure as the norm.

Hey NotFuzzy, regarding your back-up power source being a genset, have you ever had to run your miners off of that back-up? I'm curious is there's any power quality issues from a genset that would require some kind of protection for your miners, say a UPS or something in between? I'm curious to know what I will need to consider in regards to design if I also use a back-up genset.

Yes I've had miners running on the generators both at home and at work with no issues (as expected).

The only power quality issue a generator usually will have is frequency control when large loads like AC or a refrigerator turn on/off (speed of motor changes briefly making freq change) and miner PSU's could care less about it. If the only thing on the genset is miners then the load will be very steady anyway.

As for UPS's - that is another story. Depending on just how much freq changes a UPS may pick that up as a problem and switch over. The brief transfer time may cause another blip in load causing another blip in freq, rinse and repeat. The specific Cyberpower UPS's I use have a generator-mode to address that.

The way I see it you need a pretty damn big farm to justify a UPS and back up generator if it's just for the miners.

In terms of design, I've never seen a back up gen used without also using a UPS but it can be done.  You will have to consider how your going to transfer the load between the gen and utility power. For uninterrupted power you would need an ATS (automatic transfer switch) and UPS.  The UPS holds the load while the gen fires up, when the gen is ready the ATS transfers the load onto the gen.  When utility power returns the ATS moves the load back to normal utility operation.

Always use an online UPS with a generator (as noted above)

No UPS and load drops when utility fails and gen starts up.
No ATS and you will have to manually transfer the load between utility and gen.

Most normal electricians are not qualified for this kind of work, consult and hire a real professional for this kind of work. And lastly do the math and make sure its worth it for mining LOL!!

Definitely agree with you Hellfish!
For data-critical operations seamless hold-over until the generators come online is essential.

In my example above, since mining can afford to be offline and more casually restarted in a manual orderly manner, not needing the UPS system to say least saves mega $$$.

As for companies qualified for it, Schneider Electric is first to mind. Hell they will even do cooling needs along with designing the buildings...

2x1600 = 3200/120 = 26 amps (RMS) or not this is a lot of power on a normal 14 gauge home wire. Not knowing what you have going as far as a power distribution center as in LOAD CENTER you may want to have a qualified individual check your wire for correct size for the power being drawn through them and all connections in the load center. Drawing that kind of power I would have a separate circuit each - 10 gauge copper on a 30 amp circuit breaker. Connections that run hot as in too small of wires cause connections to become loose over time and unsafe. Have the qualified individual check all neutral wires as in a home wire environment  neutral connections are one of the main spots for intermittent power losses.
Personally I have 2 heavy duty 10 gauge power extension cords from home depot each on a 20 amp circuit for each machine directly from the load center.
This way I don't have to worry about someone plugging in any appliances that may affect my power - Like a hair dryer lol.
 ::)

14 AWG wire is rated for 15 amps MAX by the NEC.
12 AWG wire is rated for 20 amps MAX.

 You need to go to at least 10 AWG.

 It's not practical to use a generator without a UPS unless you are willing to suffer through a short power outage before the generator can kick in, *OR* the generator is running all the time (EXPEN$IVE) and you have a VERY fast automatic transfer switch setup (ALSO expen$ive).



 IMO it's not cost effective to use a UPS on a miner - if your power drops out more than once every couple of months you're going to have issues with mining anyway, as you're probably going to lose your internet connectivity as well fairly frequently.

You should a 30kV UPS and connect it to a gas generator, this way you have endless power. :)