Overview - BITMAIN APW12 Manual

Overview

The APW12 Bitmain power supply is a robust, high performance power supply that is
capable of powering most Bitmain X19 and X21 mining rigs, but in its factory
configuration, it requires at least 200V AC at its input to work properly. This guide gives
instructions for modifying the APW12 to allow it to run from 120V AC.
The APW12 has 2 input power legs. Each input leg has its own brown out detector
circuit that prevents the APW12 from fully powering on if the input voltage of either leg is
below 200V AC. This ensures that the APW12 has enough input voltage to supply the
fully specified output power. Unlocking the APW12 to work with 120V AC requires
adding 2 resistors to the brown out detectors' sense resistor networks on the back side
of the PCB. See the "Modifications Steps" below for more details.
Before proceeding, it must be understood that running the APW12 from 120V AC will
significantly reduce its maximum output power capability. The APW12, in its factory
configuration, is capable of delivering up to 3600 watts of power when powered from
240V AC. If powering a modified APW12 from 120V AC, care should be taken to not
overload the 120V circuit. See the "Hashing from 120V AC" section below for more
information.
Unlocking the APW12 will enable it to power most Bitmain X19 and X21 mining rigs
from 120V AC, but the miner's power draw must be significantly reduced to avoid
overloading the circuit. See the "Limiting Miner Power Draw" section below for more
details.
There are many variants of the APW12 (e.g. APW121215a, APW121215e,
APW121417a, etc.). At the time of writing this guide, it is believed that the modifications
outlined in this guide will work for all APW12 variants.
Document Revision 3
3
2024-02-01