Bitcoin Forum

Alternate cryptocurrencies => Mining (Altcoins) => Topic started by: Vann on December 12, 2017, 11:24:40 AM



Title: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: Vann on December 12, 2017, 11:24:40 AM
Wanted to share what happened when I used a dual 4-pin molex to a single 8-pin PCI-E VGA power adapter with a Sapphire Nitro+ RX 570 dual mining ETH that also had the 6-pin plugged in from a different PSU cable. The PCI-E 8-pin connector is rated for up to 150 W and clearly the 18 AWG copper wire wasn't able to handle the constant draw despite being split over two molex connectors.

A heads up to those who use 18 AWG wire in adapters and spitters to power 8-pin PCI-E VGA power connectors. If you're PSU doesn't have enough 8-pin connectors for all your cards, you NEED to get a bigger PSU or use a dual PSU setup so that you have enough connectors fto run all your cards safely.

https://image.ibb.co/jBK57w/Burned_Dual_Molex_To_8_pin_Adapter.jpg


Title: Re: 18 AWG Wire And 8-Pin VGA Power Connectors
Post by: Turkish88 on December 12, 2017, 11:30:04 AM
Шt happened because you used defective converer from molex to pci-ex
Bad contact will be on 12V connector. Best way cut of connector and solder wires directly


Title: Re: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: Vann on December 12, 2017, 11:34:19 AM
I made sure the molex connector pins were fully seated. The cable was burned through on both sides from the high constant draw from dual mining.


Title: Re: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: nc50lc on December 12, 2017, 01:10:45 PM
It's clearly a low quality converter!
Believe me, I have a good eye on catching knockoffs.

The Plastic used for the 4pin - Molex has too many sharp-edges and untrimmed excess plastic around the sides.
The 8-pin PCI-E Power too, it's too sharp, I can literaly cut my skin with that.
I highly doubt the material used for the wires.

But you were right about using a bigger PSU.
If the rig is dedicated for mining, make sure the total power required by the whole system (at stress) is at 40-80% of your PSU's.


Title: Re: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: nshyamkrishna on December 12, 2017, 06:01:15 PM
Its is due to improper contact between molex pins and wire. 


Title: Re: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: P00P135 on December 12, 2017, 06:10:31 PM
Moral of the story don't use shitty adapters on your rigs that are running full load 24/7.  If the adapter is questionable at all... don't use it.


Title: Re: Burned 18 AWG Wire And 8-Pin VGA GPU Power Connectors
Post by: Vann on December 12, 2017, 06:17:25 PM
The problem is not the connector or the molex pins, it's that 18 AWG wire is rated at 10 A MAX, which at 12V is 120 W and that is for a short run, not a constant draw. A PCI-E 8-pin connector is rated for 150 W which is 12.5 A at 12V. That is why the 18 AWG wire burned up from being overloaded with a constant high draw exceeding it's capacity from dual mining.

I felt that splitting the load over two molex connectors would be enough to reduce the draw on the wires. Clearly that was not the case. If you're going to use adapter's for a 8-pin on a mining rig, go with at least 16 AWG which is rated for 20A and 240 W at 12V.

https://image.ibb.co/i495Cw/Screenshot_from_2017_12_02_13_05_36.png

http://www.rowand.net/shop/tech/wirecapacitychart.htm