Bitcoin Forum

Bitcoin => Mining support => Topic started by: scyc on March 05, 2020, 09:04:11 AM



Title: Warm cables/power cords
Post by: scyc on March 05, 2020, 09:04:11 AM
Hi all,

I've been running several machines, and over time I've experienced very warm power cables to the point they melt. The standard 1mm(2) or 1.5mm(2) just can't cut it for 1600W devices.

So I've made my own. 2.5mm(2) cores, with MK plugs and power amp socket adaptors. Seems to be holding well (for now!)

https://pasteboard.co/IXEVZGn.jpg


Title: Re: Warm cables/power cords
Post by: DaveF on March 05, 2020, 12:12:08 PM
<Removed due to false virus warning>
See here: https://bitcointalk.org/index.php?topic=5182222.msg53969243#msg53969243 (https://bitcointalk.org/index.php?topic=5182222.msg53969243#msg53969243) seems to be an interment issue with the image hosting site.
-Dave


Title: Re: Warm cables/power cords
Post by: philipma1957 on March 05, 2020, 12:40:17 PM
I get a good link with zero issues
it looks to be secure

and his cables look attractive

I used a mac and safari browser

I wonder why you got other then what I did.

https://i.imgur.com/0B4t7tC.png (https://i.imgur.com/0B4t7tC.png)


Title: Re: Warm cables/power cords
Post by: mikeywith on March 05, 2020, 02:13:49 PM
I get a normal image view just like phill stated, Dave might be having an issue with his browser or his ISP blocks the website.

OP, if 1.5mm2 melts over a 1600w then it is one of two:
1: your voltage is terribly low
2: the wire size is mislabeled which is normal for most of those cables to be 0.5mm2 and the manufacturer claims they are 1mm.

1mm(2) is more than enough for 1600w if your voltage is above 200v.


Title: Re: Warm cables/power cords
Post by: DaveF on March 05, 2020, 02:32:30 PM
Yes the cables do look good.

3 different PCs on 3 different networks popped as malware.

Blocked by malwarebytes on one, a sonicwall on another and a barracuda on the 3rd.

With that being said, it might be that there is / was an ad that was being displayed that is / was causing the issue.

googling a bit there have been issues from pasteboard.co on and off for a while now with this.

-Dave


Title: Re: Warm cables/power cords
Post by: philipma1957 on March 05, 2020, 02:45:02 PM
Better safe then sorry.


Title: Re: Warm cables/power cords
Post by: mikeywith on March 06, 2020, 03:04:24 AM
Blocked by malwarebytes on one...

I got the same results when trying with a different PC that has Malwarebytes on it, blow is the warning I get when trying to access pasteboard.co.

https://i.ibb.co/MNZc0tK/blocked.jpg (https://i.ibb.co/MNZc0tK/blocked.jpg)


Title: Re: Warm cables/power cords
Post by: scyc on March 06, 2020, 04:44:50 AM
Apologies for the malware issues. I won't use that image site again.

The problem with buying cables in Hong Kong for mining is that the quality of the copper isn't so good on these mass produced items. I was told to go and buy them from Germany instead.

These cables cost around 1700 HKD at least premade, but I got them made up for 200 HKD sourcing each part individually that I felt seem good quality.

One rig did melt all the cables when I put in 3x S9 14T's on a standard 13 Amp power strip (+another server). Lasted for a year before the cables, power bank all disintegrated. The plugs were welded into place  :o

I'm now running DragonMint T1's but they seem to be pulling tons of power.


Title: Re: Warm cables/power cords
Post by: philipma1957 on March 06, 2020, 04:55:28 AM
do you run the t1s at factory or at performance modes.

try balanced.

i had five of them they pulled a lot of power unless you dropped to balanced.


Title: Re: Warm cables/power cords
Post by: scyc on March 06, 2020, 05:45:57 AM
I'm so glad you mentioned this, I'll need to check but that might explain why the fans are like twin turbo jet engines 24/7.

To be safe, I'm running 2x T1's off a standard 13 Amp, 220-240 power strip. If I set the miners down to Efficiency Mode, do you think I can safely run 3 in total?

Thanks,
Stephen.


Title: Re: Warm cables/power cords
Post by: lightfoot on March 06, 2020, 05:49:33 AM
What kind of power supplies are you using? Power cables are usually rated in amps, but do not take power factor into their calculations. If a power supply has a PF of .8 then you'll actually be pulling 20% more Volt Amps than the watts you think you are pulling. Good power supplies can have a PF of .9 to .95, big difference.

Moral: You have to size your cables and plugs for volt amps more than watts. I've seen this happen a number of times.


Title: Re: Warm cables/power cords
Post by: scyc on March 06, 2020, 06:50:30 AM
What kind of power supplies are you using? Power cables are usually rated in amps, but do not take power factor into their calculations. If a power supply has a PF of .8 then you'll actually be pulling 20% more Volt Amps than the watts you think you are pulling. Good power supplies can have a PF of .9 to .95, big difference.

Moral: You have to size your cables and plugs for volt amps more than watts. I've seen this happen a number of times.

I'm using the 1600W power supply from Halong. I'm not sure of their PF?


Title: Re: Warm cables/power cords
Post by: Artemis3 on March 09, 2020, 04:14:06 PM
Cables meant for servers (rack) or large photocopiers usually do the trick, sometimes the ones for (large) laser printers are also thick enough.

Indeed, the higher the voltage the less amps you need to run across those wires given the same consumption. This is why 240v is better than 120v...

Note that China uses 230v, so, they might get away over there with a (fake thick) cable that would melt using 120v... I guess cutting the thing is the only way to find out the truth. HK should be on 230v too... (Originally 220v, not sure if updated to euro levels).

I think importing from Germany is a bit overkill :)


Title: Re: Warm cables/power cords
Post by: lightfoot on March 09, 2020, 05:57:13 PM
I'm using the 1600W power supply from Halong. I'm not sure of their PF?

Interesting, I just got a Dragonmint in here as a reference box for the repairs and it came with a Halong power supply. Damn thing is reading a power factor of 99% at 450 watts (one board, econo mode, 110v input) which is pretty damn good.

Went out and checked two other miners in the workshop: The Bitmain 1600 PSU has a power factor of .99 under a thousand watt load and the HP datacenter power supplies also have a .99 at 600 watt load each. By comparison the ATX cheapo power supplies have around .8 and the ATX Gold/80 certified ones are .9

Moral: Bitmain and Halong may have their own problems, but their power supplies are pretty good. The watts you are pulling match the volt amps that are heating up the cables.