I have an electric dryer (Samsung DV42H5000EW) and it is connected to a 30A (I believe it dual 30A as there are 2 arms that are connected to each other both saying 30A) 240V breaker. The wall socket is a 10-30R connection at the dryer. I believe 10-30R sockets require 240V if I am not mistaken. The house was built maybe 10/15 years ago. I am guessing the wiring is still good and nothing wrong (that i have seen so far)
I am running some bitcoin/altcoin mining equipment from this wall socket when the dryer is not in use. The equipment came with China GB2099 to C19 power cords. They use 2100w. I am in the USA so these cords will not work for me.
What I ended up doing is getting a 10-30P to L6-30R converter, and purchasing a L6-30P to C19 so that I can connect it to the mining equipment.
This works perfectly. I can run one of the machines off of this all day with no issues.
I figured since it's 30A 240V I can technically run 2 of the 2100w machines on the same power outlet as I am below the 5760w (80% continuous load threshold). I purchased a C20 to x2 C19 splitter so I could connect both machines. I ran it for 2 or 3 days with both of them running without any circuits popping or issues with the machines themselves.
My wife asked me to turn off the equipment so she could use the dryer. When I did I noticed the plastic receptacle (10-30P) was warm to the touch as was the first 6 inches of the wire. But both of the hot (Left/right) prongs on the 10-30P were HOT. I could only touch them for a few seconds without having to take my fingers off. The top/bottom prongs were just warm. I checked the rest of the cables and nothing was hot/warm anywhere else. Just on the 10-30P and first 6 inches of wire.
Once my wife was done with Laundry, I checked the 10-30P (for the laundry machine) and it was not warm at all. I reconnected the mining equipment and ran
both of the machines again for a few hours and checked the 10-30P. Same thing. Receptacle was warm but the hot prongs were HOT.
I let it cool down and connected it once again but only one of the machines this time for a few hours and the 10-30P was not warm and the prongs were barely warm. I know the circuit can handle the load as I am well below the 80% threshold.
Do you think the wall socket (10-30R) needs to be replaced. The 10-30P to L6-30 connection? Should I not be running this load on this socket/circuit? Did I put myself in danger by running them both on the same circuit?
I am a little confused as to why it's getting so hot if it is rated to handle that load. I figured I would try to get some help here before I call and pay an electrician.
Thanks in advance.
— Edit
Thank y'all for the help. I instead opted to setup a co-location contract with a local data center that will provide the power/cooling/facilities at almost the same cost it was for me to run it in my garage. Safer and much more of a legitimate location for the equipment. I am having an electrician come out to replace that plug with the 14-30 like suggested. i did not know it was outdated.
Best Answer
The reason that certain sized wire must be used for a given amperage is because the wire gets hot when electricity is pulled through it. That said, some equipment from China isn't known for complying to all the regulations we have, and the conductors in the adapters could be undersized.
Many conductors and connectors are rated for 75C, which is 167F, and certainly hot enough to burn you. However I don't think anything that you can easily touch should get that hot while in use, so I would assume that something is wrong. I would suspect the adapter first, but you should also measure the amount of current the equipment is using. It could be pulling a lot more than you think (closer to 7000W) which would overheat an adapter that was probably meant for closer to 4000W.
If you wanted to tinker with the wall outlet, you can make sure the wire clamping screws are tight, and they have a good, solid connection. The dryer works, and the computers work, so I don't think anything is "wrong" with the wiring itself.