My single Phase 235 volt T21

So there’s this cool thread by Danieleither. It covers the hassle of getting T21 units when you’ve got three-phase power. I ended up in the same boat as Daniel, ordered three units and only got two on the way. I’ve got single-phase 230 and I was pretty mad about it. But after some digging and brainstorming thanks to some ideas from Danieleither’s thread I managed to get my T21 up and running with a 230-volt PSU. Just to share, my meter shows 2782 watts for 157th which breaks down to about 17.72 watts per th. The software number is reporting higher, around 3050+.

spacer so some power numbers 157th with cold air 45f open garage door  burns 2750 around 17.7 140th with cold air 45f  garage door burns 2460 around 17.5 will do 175th next.

spacer. Parts needed a bitmain T21 miner the correct controller I have the Civtek it is no good. the epic controller with firmware 42 is mint and works. proper buss bars. I ordered them from Altairtech but got short ones. my s19xp has the right buss bars. a s19 psu. parts list from altairtech. controller https://altairtech.io/product/epic-umc/ psu https://altairtech.io/product/epic-umc/ four pin pwm fans as the fans that come with the t21 have wrong connector. epic controller wants standard four pin fans. https://altairtech.io/product/antminer-120mm-replacement-fan-for-s19-s17-s11-s15-and-s9-series/ Note the bus bars I ordered below are no good I will ask Altair-tech to check the rest of them. so they do not get sent to you and they are short mine were under cut by ¼ inch. https://altairtech.io/product/antminer-power-bar/ I am tired will post more later tonight.  edit the buss bars are not long enough

spacer garage door shut room kind of warm watts are  2868 hash 157 garage opened cools off around 20-30f with temps cooler watts drop 2758/  th 157 = 17.5 watts a th for the t21 pretty fucking good.

here it is set to 180 th. note it says watts are 19.1 meter gives me 18.5 and if I open the garage door to cool room meter gives me 17.5 watts a nice piece of gear. two more on the way.

I am very ambitious about these T21's I purchased an alpha miner psu. It can do 7000 watts it is meant for liquid cooling I intend to A) mod it for air cooling B) use a buck boost transformer to boost volts to 255 add this setup to the T21 the psu can do 300 volts the transformer can do 7000 watts. in theory the t21 can over clock to 230 th in theory the alpha psu can provide the watts needed. This will take until late may as the next 2 t21's come in may.

Happy to see folks trying to get T21 to work on single phase. We've done this on a couple of test rigs and can't really tell a performance/efficiency difference between T21 and S21. Yet the T21 is considerably cheaper, and comes with a Bigger PSU. One issue I've encountered is that after you change the PSU and power bars, there doesn't seem to be an easy way to cover the power bars etc, since T21 does not come with a PSU cover piece.

yeah and the s19xp psu I used the cover does not quite fit. I have three of these t21s i can get them to do 205th at 17.5 watts in a cold room. i am going to experiment with the alpha 7000 watt liquid cooled psu. in theory the t21 can clock to 231 th with the correct psu.

Hey Phillip! Any updates on this project? I have some T21's and some S19 PSU's. I'm thinking about trying this out. Frankenminer FTW! Altair makes a cover for the power bars for this conversion. Not sure if they sell it seperate or only in their conversion kit.

Runs great so far. I used black duct tape to cover the open buss  bars. I am getting two more t21 s maybe I will ask Altair tech to ship a cover for them. I will need some more parts. Get the epic controller and use firmware 42 or 44 I have run it 60th to 195th zero issues. And on colder days it can do 17.8 watts a th at 160-190 settings. Heat can make you do 17.8 to 21 watts

Just shipped you a couple of complimentary T21 Transformer PSU covers. The bars aren't a shock risk but still pose short circuit risk.

Is the epic controller necessary? Altair does not list it as part of their conversion kit. I'm thinking I can use the stock controller and flash it to vnish.

That's super cool Altair!

don't know if that works maybe it does.

T21 stock firmware errors out on APW12, so you would need aftermarket firmware to run after swapping PSU from APW11 to APW12. For the fully assembled 'T21 transformer' we just ship with vnish on stock AMLOGIC control board. We have tested this build with both ePIC UMC and MARA UCB and it works with both, but they do add some additional cost to the build. Both these CB options are nice since they have zero dev fees , so will likely pay themselves off over time. But if you're looking to save on upfront cost, you can just flash luxos or vnish on the stock AML CB and it works fine. Now if your T21 came with a CV1835 control board, that changes the math, since there is very few firmware option available. In this case, your best bet is to just remove the stock CB and replace with epic or MARA.

Yeah I had the cv1835. I ORDERED and received some epic boards for the two t21 units coming this month. I rave on about epic boards as I have found them to work better than any board I ever used. I will end up needing 3 covers to prevent shorts. The electric resistant duct tape is sloppy looking. I have a ton of psu's from my s19s. I hope to end up with 4 or 5 miners once I sell off all my other gear. One L7 THREE MODDED t21's Maybe a gpu rig. Oh two nano 3's This would do about 14kwatts an hour.

I'd be interested in buying some covers.

S21 is better than T21, most of our clients choose S21 instead of T21

I've listed the PSU cover as a variant on the T21 transformer listing https://altairtech.io/product/bitmain-antminer-t21-transformer/

Do you know you shipped the covers out the other day and in under 10 hours bitmain shipped my remaining  t21's I will soon have 3 of them up and running.