Quote from: john139 on May 07, 2019, 07:35:33 PM

Most of second hand miners are supplied by Chinese and As the BTC price rises they increase the price. Today I inquiry from China for 20 second hand, S9s , 13.5 TH (30 days warranty remains) including psu for 246 $ without shipping cost.

You can buy that it's too cheap but are those used units strong ? No.

Everywhere Alibaba Aliexpress eBay etc. I've asked sellers about lifespan of an used S9s and their response was "if you run it 24/7 it will be dead after 6 months."

So buying used S9s cannot calculate profits, they say 6 months but it may be dead after few weeks, who knows.

Quote from: philipma1957 on May 07, 2019, 05:58:09 PM

... OffordScott is good.

He has a link here.

https://bitcointalk.org/index.php?topic=5138318.0

he also has telegram channel.

on telegram.

I do not trust him, what I see he have sold many miners but no one have rated him here, that's why I do not trust also his personal website is a joke not from a professional.

Quote from: NotFuzzyWarm on May 07, 2019, 05:17:24 PM

One big enough to handle the amount of power you are using. That in turn depends on your power line voltage, if using 208v then the 40kw you mentioned = 192.3amps feeding the circuit breaker panel. That gets split up depending on how much power each individual miners uses. For s9 and such (around 1,250w each) you can use a 15A outlet to power 2 miners.

You need to work with a licensed electrician to get the proper power outlets and circuit breakers wired per your area codes. If you do not do this for a living DO NOT just follow internet opinions about wiring. The risk of electrocution or fire is too great.

I've asked a electrican and he told me for that power it's needed a cable 35kV, cost is very high for 35kV in my country. He told me may cost 3-5kEur.