Converting Antminer T21 Power Supply to 220V Guide

A detailed guide to upgrading the PSU of the T21 miner to run from a standard single-phase 220 V grid using VNISH firmware.

The Antminer T21 is practical in terms of energy efficiency and comes close to the flagship S21 series. However, the stock T21 is designed for three-phase power (380V), which makes it difficult to deploy at sites without access to 380 V.

Fortunately, the device can be adapted to a regular single-phase 220V–277V grid. Below you will find a comparison of the basic specifications, a list of the required components, and the conversion procedure.

■ Specifications comparison: T21 vs S21

Parameter	Antminer T21 (Stock)	Antminer S21
Algorithm / Coins	SHA-256 (BTC/BCH/BSV)	SHA-256 (BTC/BCH/BSV)
Hashrate	190 TH/s (±3%)	200 TH/s (±3%)
Power consumption	3610 W (±5%)	3500 W (±5%)
Energy efficiency	19.0 J/TH	17.5 J/TH
Power supply (native)	3-phase (380–415 V)	1-phase (220–277 V)

Components required for the conversion

To convert the T21 miner to a single-phase 220 V grid, you will need to combine the busbars with an original Bitmain 220V power supply unit of one of the following models:

Bitmain APW121215 PSU (Versions: a / b / c / d / e / f)
Bitmain APW171215 PSU (Versions: a / b / c)
Matching power busbars from the PSUs listed above.

■ Step-by-step modification process

1
Remove the stock PSU: Disconnect the power, then carefully remove the three-phase 380V power supply and the standard busbars.
2
Install the busbars and the 220V PSU: Mount the new busbars for the APW121215 or APW171215 model and install the compatible single-phase PSU.
3
Flash VNISH firmware for T21: Install VNISH for Antminer T21. The firmware recognizes the changes to the power circuit and ensures the correct initial voltage supply.
4
Startup and auto-tuning: After flashing, the miner will start normally from a 220V grid. Thanks to the VNISH algorithms, you can precisely adjust power consumption and optimize hashrate.