Topic: Announcement: Bitmain launches AntMiner solution, 0.68 J/GH on chip - page 109. (Read 368330 times)

Curious to see how that's no problem when a single OC ant @ 400Mhz already uses over 500w
(let alone the indicated 1000w is not only 12v and you should never push a PSU to it's max for a long time)

Yes, that will be no problem.

Question for you PSU gurus out there - do you think 2 ANTS OC'd @400mhz/200ghs will run fine/safe on an OCZ 1000W 80+ gold PSU rated @90% efficiency?  They will be on their own 20A/125V circuit.

Thanks in advance for any guidance.

With 650 or 750 bronze PSU and 220V.

http://www.reddit.com/r/Bitcoin/comments/1vu7z0/ghash_8_rejected_blocks/

Well the suppliers cutout (fuse) that is sealed to prevent the customer interfering with it, is just before the metering (usually no more than .5 mtrs from the switch board) so it is protecting very little before the outgoing circuits. Really its true purpose is to protect the incoming cable (although its on the wrong side, not the best design.)  But it stops you overloading the main cable.

I haven't been in the UK for a while, but just checked a uk wholesalers website and they are still selling the Switchboards with a Double Pole 100A Main Switch so am guessing they haven't moved on there yet.

Technically the Main Switch is only for consumer Isolation, it provides a minimum gap (Air) for safe work.

Here in Australia it has been common to replace the Main Switch with an MCB, as the use of overhead lines here is common and this cabling more often than not travels some of the roof space before reaching any consumer protection, this is a very good idea.

However, (and I could be wrong here) as far as I was aware an MCB does not provide a significant air gap to be classified as a Main Switch or Dis-connector for the purpose of Isolation and safe work.

Am really interested how this pans out for Aussies, am sure the Electrical Safety Office is aware of this issue as they have directed us to remove the main link (solid fake fuse) before caring out work however this requires resealing by the supply authority afterwards..

So Technically Aussies have no safe electrical disconnection on the consumers side.

Anyway this has gone way off topic now   so let me just say.

If in doubt contact an Electrician

Anyone know how to manually switch pools on the Antminer?
Ghash is down and all of them are stuck

Yes, I suppose I should have been more specific there. The derating is for your main circuit breaker. That's interesting that in the UK there is no customer side main protection in the form of a fuse or CB. I don't imagine that's current code, but how long ago was it standard to have the main fuse on the supply side and only branch fuses on the customer side?

Further note: Just because your Main Switch or Main Isolator are rated at 100A or 200A does not mean you have that supply available.

Most Old UK and Australian domestic services will have 100A Switch Disconnectors as a Main Switch however they are fused at 60 or 80A on the supply side (in the street). Which is why Main Switches are being replaced with MCB's of a sutible rating so the supply authorities fuse will not blow ( as the supply authority have recently started to charge the customer when it does).

Things are never straight forward.

A Main Switch is just a switch, If it is rated @100A it is designed to switch 100A on occasion. (manual switching). It could possibly take double that current for short periods without problems (I would not recommend this). It is just a switch.. and provides zero protection only a means of disconnection and Isolation.

To confuse the matter further sometimes MCB's are labeled Main switch, as they are providing a means of disconnection and additional protection.

At my current location it is favorable to use an MCB instead of a main switch. I would not recommend exceeding 80% of its current rating for continuous use. Unless you want nuisance tripping.



Most domestic MCB's are type C on sub-circuits, if you are happy that you have a decent sub-circuit (short and correct cable size with few additional outlets) you can always replace this with type D if you wish to limit tripping ( these are predominantly used in industry for items like motors to get over the start surge, but maybe useful if you switch the whole rig on at the same time and your mcb trips)

More common in new installations now are combined mcb/rcd or RCCD's and in some countries RCD protection is compulsory on circuits containing socket outlets. I am not aware of any RCCD's that are not of type C without great expense. These provide an additional layer of protection by monitoring the current on the live and neutral conductors and disconnecting if there is an imbalance between them. Test them every 3 months.

Each circumstance is very different and blanket statements can be dangerous, I would not like to comment on the above case as I have never dealt with US 110V, most electricians will give advise for free in hope of further work..

If you are getting close to the ratings of your circuits consult an electrician, think about your future plans first as a sub-board would probably be beneficial to many of you guys in the US.

It appears that you are also probably right.

I work at a power utility however, I am not an electrician so I don't know for sure.

You are correct, and I didn't say otherwise. What I said is that you don't derate it twice. Derate the main breaker 80% for continuous use (160A in your example), and derate each branch by 80% (12A).

I know for a fact that 99.99% of all mainswitches are 80% rated.

I got a stock Antminer with a i700 CoolerMaster PS it use's 388 VA or 386 Watts @.99 PF at wall on 120 volt.

No, your branch circuits are rated for no more than 80% continuous use. I don't know why you're derating the main service twice. You should derate your main breaker as well but the branch circuits don't affect that, it's just a function of the breaker. You can still have 16 10A loads on that breaker and be safe. Each branch shouldn't be run more than 80% except intermittently (eg, a big temporary draw like a microwave or kettle) though, and since mining is hopefully 24/7, no more than 12A on a standard 14 gauge 15A branch.

That being said, I wouldn't run even 12A continuously on a standard house branch circuit. 14 gauge wire has a resistance of 2.525mOhm/ft, so if you have 50 feet of NMD-90 between the panel and the outlet you are running through 100ft of wire (hot+neutral). 12A*12A*0.2525Ohm = ~36W burning up just in the house wiring.

Short runs of thick wire, why waste power when you don't need to?

The mainswitch is 80% rated but I think the branch circuits are 100% rated.

If the branch circuits where also 80% rated then a 200A service would only be good for 128A continuous.

No, no, no. Do not run a circuit at 100% 24/7. You max 80% continous load.

15 amp circuit: 12A @ 120V = 1440W.
20 amp circuit: 16A @ 120V = 1920W.

+ 1 on the PSU

In order to get the best efficiency from you PSU you can only load it 50% and the more efficient it is the less power it will use at the wall.  Comparing a Plus 80 to a Plus 80 Titanium for example using the formula [PSU utilization] + losses = [Power at wall].

350W + (350W - (350W * 0.80)) = 420W * 4 = 1680W

350W + (350W - (350W * 0.94)) = 371W * 4 = 1484W

So just by running efficient PSU's loaded 50% can be the difference between being able to run 3 miners or 4 on 1 breaker.

With this in mind, I would recommend running nothing less than 750W bronze PSU's for each miner.

I don't think you could run 5 on one breaker but if someone could show me some numbers I would be interested to take a look at them.

It really does depend on how good your PSU is.

15A * 110V = 1,650W

Stock clocked ant on a very good PSU pulls 350W, overclocked pulls 400W. 4 ant's is your maximum but if your house circuitry is old then personally I would only use 3 ant's because of the burnout risk from old cable.

Ah I see. So 440W at the wall with what PSU and what voltage (120/240?)