Ninjastic
PostEdited versionsQuotes to this post
Post
Topic
Board Hardware
Re: ANTMINER S4 Discussion and Support Thread
by
NotFuzzyWarm
on 30/10/2014, 11:52:14 UTC
Quote from: dogie on October 30, 2014, 12:00:38 AM
Quote from: NotFuzzyWarm on October 29, 2014, 11:23:48 PM
Quote from: dogie on October 29, 2014, 04:03:23 PM
Quote from: NotFuzzyWarm on October 29, 2014, 02:35:10 PM
As for US residential powerlines... this should be a major design concern for Bitmain or any other miner mfgr because PSU's do NOT like low lines... In Detroit area home power is 110v - not 120 - and during summer will often drop to 100-105v. The '220v' incoming reflects the same drops. This year it got so bad (hit 95v for 2 weeks) I had to wire in a boost transformer to make up the difference...

I'm not sure anything can be done for that. The vast majority of the market doesn't have that problem, and one which will affect all electronics.

'All electronics' - and more. Gas clothes dryers and stoves did not want to work either because the igniters would not come up to temp...

In this instance the problem only really affects PSU's being pushed to near max output. What to be done? Easy answer, appropriately de-rate the PSUs like HP did with their CS server PSU's so it can run on a low line and still produce required power. Then it is just a matter of balancing cost/benefit. Frankly, given how vocal folks can be here when there is an issue I'd err on making sure they can go down to at least 100v to cover wiring in old homes & apartments.

1400w miners aren't designed for old homes and apartments, and its not fair to make every customer pay another $20 a unit for that small minority. Frankly I'm surprised your derating problem is even legal in the US.
They may not be designed for old homes/neighborhoods but without a caveat about that you know folks will buy them and try to use them there... As for the low voltage being legal, well, MI utility rules say that power must be within +/-10% of nominal. Since our nominal is 110v that means even down to 99v is 'in-spec'.

As for that 2-week spate of 95v (and lower), that was a pure bad timing - a big storm ripped through a couple weeks before taking out power lines, while those were being repaired another big storm rolled through and did the same thing again so I guess we were lucky to have power at all. My whole-house generator got a good workout during that time as I said screw it and killed the main feed into the house until the lines were repaired...