400uH 20A Toroidal PFC Inductor – Bitmain APW17 PSU Repair

400uH 20A Toroidal PFC Power Inductor – Bitmain Antminer APW17 (1215A / 1215B / 1215C) PSU Repair for S21 / S21XP / S19jXP / KS5 / L9

This 400 µH, 20 A toroidal PFC power inductor is developed specifically for the repair and replacement of Antminer APW17-series power supplies — APW17 1215A, 1215B and 1215C. It uses flat copper enamelled wire wound on a toroidal core and sits in the PFC (Power Factor Correction) circuit of the PSU. It fits the APW17 that powers Antminer S21, S21 Pro, S21XP, S21++, S19jXP, KS5, KS5 Pro, L9 and L11 miners, and resolves the standard PFC-inductor failure family: inductor overheating, magnetic saturation under load, coil burnout, and PSU that refuses to start up.

Built with industrial-grade components and drop-in fit to the original APW17 mounting dimensions, so it swaps directly into the board with no PCB modification — the standard bench repair when the OEM inductor has failed.

5 Core Features

1. Flat enamelled copper strip winding — stronger current-carrying capacity and lower DC internal resistance than a round-wire winding. Less heat generation under high-current operation, and lower risk of tripping the PSU's high-temperature protection.
2. Toroidal low-loss magnetic core — excellent saturation characteristics under high-frequency PFC switching, prevents magnetic saturation at full load, keeps power factor stable across the miner's load range.
3. Coil bottom reinforced with black epoxy resin — prevents the coil from fraying or detaching under the high-frequency vibration of a running mining rig chassis.
4. Wide operating temperature: -40 °C to +125 °C — designed for the high-temperature environment inside a PSU running 24/7 at full load.
5. Purpose-developed for the APW17 PFC circuit — a core replacement component for APW17 PSU repair, not a generic industrial part retrofitted to fit.

When to Replace the APW17 PFC Inductor

• Inductor overheating — visible discoloration around the coil, PSU throttling on temperature protection under load.
• Magnetic saturation — PSU output collapses under full miner load even though secondary-side components test fine.
• Coil burnout — open circuit on the winding, blackened epoxy, visible damage.
• PSU won't start — no boost stage output, PFC front-end reports fault, miner cannot power on.
• Preventive replacement during a full PSU rebuild — when other primary-side components (SiC MOSFETs, PFC controller) are already being swapped.

Application Scenarios

1. Repair and replacement of Antminer APW17 1215A / 1215B / 1215C PSUs — the primary use case, drop-in fit.
2. PFC circuit fault repair for S21, S21 Pro, S19jXP, KS5, KS5 Pro and L9 miner PSUs that use the APW17 platform.
3. PFC power factor correction circuits in industrial switching power supplies of comparable rating.
4. High-current filtering and boost circuits in high-power AC-DC supplies where the 400 µH / 20 A footprint matches.

Installation Notes

Disconnect mains and discharge the PSU capacitors before opening the enclosure — an APW17 carries lethal stored energy. Locate the failed inductor on the primary side of the PSU (in the PFC boost stage between the input rectifier and the main switching MOSFETs). Desolder the PCB pins carefully — the epoxy-potted base means the part sits firmly on the board, so use a proper desoldering pump or braid rather than yanking the housing. Clean the pads, drop in the new 400 µH / 20 A inductor with the pin orientation matching the original, and reflow. Verify no cold joints under magnification, close the PSU, and re-energise via a variac under progressive load — confirming the PFC stage boosts to spec and the main output holds under full miner load before returning the PSU to service.

400uH 20A Toroidal PFC Inductor Specifications

Related Bitmain APW17 PSU Repair Parts

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• NSi8100N Isolator Chip – APW17 PSU (Control-Loop Isolation)
• LTV-817C Optocoupler 5 kV – APW8 / APW9 / APW17 PSU
• P14 Power Socket Connector – APW17 PSU

Repairing APW17 PSUs in volume or building out a bench spares kit? Contact us at contact@lys-sz.com for tray-quantity pricing on the 400 µH / 20 A toroidal PFC inductor and matched APW17 repair-kit bundles.

Worldwide shipping from our Shenzhen warehouse.