How to use Bitmain APW series power supplies? (Electrical setup)

Power Supply Compatibility Verification

1. Confirm the APW series model number matches the ASIC miner’s voltage and amperage requirements. APW3++, APW7, APW9, and APW12 each support distinct output configurations—APW9 delivers 12V/160A while APW12 supports 12V/200A with dual 12V rails.

2. Cross-check the miner’s input connector type: most Bitmain units use a 6-pin or 8-pin ATX-style main power connector alongside a 4-pin auxiliary input. APW7 requires both connectors to be engaged for stable operation under full load.

3. Validate AC input compatibility: APW3++ accepts 100–240V AC; APW9 and APW12 require 200–240V AC only. Using lower input voltage on APW9 may trigger undervoltage lockout or thermal throttling.

4. Inspect PSU firmware version via QR code label or serial number lookup. Older APW7 units shipped with firmware v1.2.5 may not recognize newer S19j Pro hashboards without an update.

AC Input Wiring Procedure

1. Use UL-listed 14 AWG or thicker copper conductors for runs up to 3 meters; reduce to 12 AWG for distances beyond 3 meters to limit voltage drop below 2%.

2. Connect live (L), neutral (N), and ground (G) to the rear IEC C14 inlet with torque set to 0.5 N·m. Reversed L/N wiring causes internal relay misfiring and failure to power on.

3. Install a dedicated 20A circuit breaker per APW9 or APW12 unit. APW3++ can operate on a shared 15A circuit only if total connected load remains under 12A continuous draw.

4. Ground the PSU chassis directly to a certified earth rod or building grounding busbar using a 6 AWG bare copper wire—never daisy-chain grounds between PSUs.

DC Output Configuration

1. Match the 12V rail color coding: yellow wires carry +12V, black wires are common ground. APW12 uses two independent +12V rails labeled “V1” and “V2”, each rated for 100A max.

2. Distribute miner hashboard power across both rails when using APW12—loading only V1 beyond 100A triggers automatic shutdown even if V2 is idle.

3. Secure all Molex 4-pin fan headers to corresponding miner fan zones. APW9 supplies 12V/1.5A per fan header; exceeding that draws from primary 12V rail and reduces available hashboard current.

4. Do not parallel outputs from separate APW units without isolation diodes—backfeeding between PSUs creates destructive circulating currents and MOSFET failure.

Cooling and Physical Mounting

1. Maintain minimum 5 cm clearance around all air inlets and exhaust grilles. APW9 draws 120 CFM at full load; obstructed airflow raises internal temperature above 75°C and forces PWM fan speed to maximum.

2. Mount vertically with fan facing downward for natural convection assist. Horizontal mounting increases internal case temperature by 8–12°C under identical ambient conditions.

3. Replace stock fans every 18 months in environments with airborne dust concentrations exceeding 0.1 mg/m³. Clogged heatsinks reduce thermal efficiency by 35% before visible debris accumulation.

4. Avoid mounting near HVAC ducts emitting condensate—humidity above 65% RH corrodes PCB traces on APW7 control boards within 6 months of exposure.

Troubleshooting Common Electrical Faults

1. No LED illumination after AC application indicates blown internal fuse F1 (5A/250V). Replace only with fast-blow ceramic fuse matching exact specs—substituting with slow-blow types permits catastrophic overcurrent damage.

2. Miner powers on but hashboards show “No Response” suggests incorrect 12V rail assignment. Verify multimeter reads 11.8–12.2V at each Molex pin; variance beyond ±0.15V points to failing DC-DC converter stage.

3. Intermittent reboot under load correlates with undersized AC feeder cable. Measure voltage at IEC inlet during full-hash operation—if reading drops below 210V on a 230V supply, upgrade conductor gauge immediately.

4. Fan spins at full speed continuously despite ambient temperature below 30°C signals failed thermistor on U12 (NTC sensor). Replacement requires desoldering and soldering of 0603 package with thermal paste reapplication.

Frequently Asked Questions

Q: Can APW3++ safely power an Antminer S19 XP?APW3++ lacks sufficient current capacity—S19 XP demands 180A at 12V while APW3++ delivers only 160A max. Overload triggers OCP shutdown within 90 seconds.

Q: Is it safe to run APW9 with only one AC input connected?No. APW9 has dual AC inputs for redundancy and phase balancing. Single-input operation disables half the PFC module, causing harmonic distortion above IEEE 519 limits and potential upstream transformer heating.

Q: Why does APW12 report “Fan Error” when using third-party 40mm fans?APW12 monitors fan tachometer signal amplitude and pulse width. Many aftermarket fans output TTL-compatible signals below 3.0V peak-to-peak, which the controller interprets as stalled rotation.

Q: Does APW7 support 12V-only mode without 5VSB standby?No. APW7 requires 5VSB presence to initialize its digital PWM controller. Removing 5VSB disables all regulation logic—even if 12V is externally applied, no output is enabled.