Hello!

This adapter is probably not going to work for you. The S19 series loves 240V source voltage. This adapter will give you 120V at each cable outlet which will likely max out the current rating on the cables going to the miner.

The other thing is technically a code limitation in Canada at least… NEC is similar I believe. Plugs cannot be fed with a breaker bigger than their rating. So the 50A breaker feeding the adapter with 20A plugs would be too large. If a cable shorts plugged into the adapter it could burn up because the breaker feeding the adapter will allow a higher short circuit current.

If you want to adapt down from a 50A plug, as an electrician, I would recommend using a small sub panel with a couple 2-pole breakers feeding each miner. I know that’s a bit more work and cost but it’s a lot safer and will help keep everything safe reducing risk of fire.

What I did for my setup was run a wire from a 2-pole 20A breaker in my panel to a junction box. I cut off the male cord ends for the miner cables and entered those cables into the box. Then spliced those wiresonto the wires from the breaker. Avoids the plug code limitations and also makes the miner easier to turn on and off because both cables feeding it switch with the breaker.