Question about powering Antminer S9s in Singapore

[cekolaw]

Hi Folks,

Greetings from Singapore.

My apology if this is not the thread to post here, please help to redirect, thanks!

I have just bought 2 used units of Bitmain Antminers S9 with PSU from eBay US sellers and they are on the way as I will be starting my home mining.

But after reading the posts here, it seems quite a concern on the wall outlet power as my thought that the miner is just like the hair dryer, and plug into a normal 3 pin UK 220/240v 13 AMPS outlet with do, or I am wrong now ...  

Can anyone advice me, please?

And i just ordered another L3+ x2 ....   worried now ... I may burn my house down...

Thank you.

[HagssFIN]

For 24h operation (0.8  x  max. nominal load):
0.8  x  (13 Amps  x  230 Volts)  --> 2392 Watts.

This is how much load you can safely have running 24h
on one 13  Amp circuit.

[mikeywith]

what is your rated voltage? it's very important specially in your case, as the numbers are very tight.

ok, just so you don't have to keep asking for every other miner you get, here is how to do the math.

you first need to know the miner consumption in wats, for S9 , it's about 1350w.

secondly you need to know how much can your circuit breaker take which is done by  calculating amp * volts.

i will assume that the voltage at your house is rated at 240v  so the equation goes like this

                                                    amp * volts.
                                                    13   *240
                                                      = 3120 wats

now at stage you are going full load, which is not the best thing to do, also keeping a lot of margin is bad , you want to stay in a very close range so that you don't overload the breaker and you don't allow much "unused" current because then your the circuit might never break in case something goes wrong.

just like HagssFIN mentioned, except that i do not agree with the number " it might be the number in the books" but to me 0.9 has been a good enough rule for years.

so you take the result from the above equation, and do multiply it by the 0.9 factor

                                                     3120 * 0.9
                                                     = 2808 wats

you can safely run 2 S9s on that breaker, provided your volt is 240.

but to be even safe, let's make it 230v . so we get thsi

                                                     13*230*0.9
                                                    = 2691w

2 s9 will need 1350*2 = 2700w so it is still some how "safe" to run 2 s9s on a 13amp circuit breaker with 230v, but it's not advisable, there is not much room for error , should the voltage drop, things will get hot and ugly.

so the best practice would be this, calculate how many miners in total you want to have on that breaker, and get another breaker.  you mentioned you getting two L3s, so you can actually safely run 1 s9 and 1 L3 on the this 13 amp cb. and get another one for the other l3 and s9.

[HagssFIN]

90% might be risky depending on his setup,
I would go with 80% like I posted earlier.

[philipma1957]

you do not have enough power to run 2 s9's and 2 l3+ on one circuit.

but the s9's now have new power saving firmware

three speeds for the s9

top speed = 1400 watts
middle speed = 1250 watts
low speed = 800 watts.

the l3+ has free firmware to lower watts

700 watts vs 800 watts at full speed.

so let us do some fast math.

1250 x 2 = 2500
700 x 2 =   1400

total = 3900

13 x 240 =  3120 watts x 80 % = 2496 watts

13 x 22  =  2860 watts x 80%  =  2288 watts

so if you do the s9's on low speed  you would use 2 x 800 = 1600

if you do the l3+  with power saving firmware     2 x 700  = 1400

3000 watts  so all four on 1 circuit is not safe.

how many circuits do you have?

note empty circuits  not used ones?

btw I will help you load software  for power savings  when you get the gear.
one last thing did you get apw3++ power supplies?

[gt_addict]

90% might be risky depending on his setup,
I would go with 80% like I posted earlier.

I Agree with HagssFIN. He is an electrical engineer after all 

[Artemis3]

Hair dryer? Please think of them like an air conditioner unit. You see how they usually dedicate a separate circuit for those? Same thing.

An S9 (1400w) can take around 8amps at 208v or 5amps at 240v, so at 230 it would be like 6 i think. But that was before asicboost, they are probably a little less demanding nowdays....

Now of course you DON'T plug BOTH of them on the SAME circuit, you just don't. There is the 80/20 rule as well (don't exceed over 80%, leave 20% margin). If you have a 13amp circuit breaker (with 13 amp rated wiring) that only serves a SINGLE S9 unit, períod.

You may serve two units with 20amps. The L3+ are 800w, you could squeeze two to a single 13a circuit as they should be like 4a each. No, you won't burn your house down if everything was installed correctly, meaning the cabling and circuit breakers. If you foolishly swap a circuit breaker with a higher rated one without upgrading its corresponding circuit wire, then you COULD cause a fire...

Do you happen to have a clothes dryer? those usually have a 30amp circuit, you could power 3 units from that.

Please note that according to EMA, it is currently unprofitable to mine in Singapore. You will lose more money in electricity than what the miners produce at current rates. If your plan is hold for the future, you are essentially purchasing bitcoins.

You will be losing about 4 USD per day per S9. You will also be losing about 2 USD per day for each L3+.
That is, unless you plan to invest in solar panels, etc.

[tim-bc]

Please note that according to EMA, it is currently unprofitable to mine in Singapore. You will lose more money in electricity than what the miners produce at current rates. If your plan is hold for the future, you are essentially purchasing bitcoins.

Not only that, but you would be purchasing them at an insane premium: 3.5x the price you would pay if you simply bought them on an exchange (based on 26c/kwh). And you run all of the risks and inconveniences of mining... the heat, the noise, the possibility of various failures...

[mikeywith]

Hair dryer? Please think of them like an air conditioner unit. You see how they usually dedicate a separate circuit for those? Same thing.

not really, the average hair dryer consumes 1500 wats, an S9 consumes a bit less than that.

the difference however is that you don't run your hair dryer 24/7.  so different set up is needed indeed.