1pc FANUC A20B-2101-0091 Servo Card Tested A20B21010091 A2OB-21O1-OO91

A20B-2101-0091 | FANUC Beta-i SVM1-20i Power PCB — FSSB and I/O Link / A06B-6130-H002 / A06B-6132-H002

Two Interface Variants, One Power Board

The FANUC Beta-i SVM1-20i servo drive is available in two communication interface configurations. The choice depends on which CNC communication protocol the machine tool uses:

FSSB interface (A06B-6130-H002): Uses FANUC's fibre optic Servo Serial Bus for axis communication — providing complete immunity to electromagnetic interference from the drive cabinet environment. Control board: A20B-2101-0050.

I/O Link interface (A06B-6132-H002): Uses FANUC's I/O Link serial bus for axis communication, addressing the servo axis as an I/O Link node. Control board: A20B-8101-0200.

Both variants use the A20B-2101-0091 as the power board. The high-current motor output stage, DC bus connections, and IGBT hardware are identical between the two interface versions — only the control board changes.

Key Product Information

Power Board vs Control Board — Division of Labour

Within the Beta-i SVM1-20i module, two active PCBs perform different functions:

A20B-2101-0091 (power PCB): Carries all the high-current hardware — DC bus input terminals, three-phase motor output connections, and current sensor circuits. It operates at bus voltage levels in normal service.

Control board (A20B-2101-0050 for FSSB, A20B-8101-0200 for I/O Link): Processes digital communication, runs current control algorithms, processes encoder feedback, and generates IGBT gate commands. Operates at logic voltage levels.

A failed A20B-2101-0091 typically manifests as output-related alarms — overcurrent under load, drive hardware protection trips — rather than communication faults. Distinguishing these symptoms guides targeted replacement to this board.

Application Scenarios

SVM1-20i FSSB drive power fault: A Beta-i SVM1-20i (A06B-6130-H002) develops an overcurrent alarm under normal load. The control board tests correctly. The A20B-2101-0091 power board is identified as the fault. Replacement restores normal drive output.

I/O Link variant service: A machine using the I/O Link SVM1-20i (A06B-6132-H002) requires a power board. The A20B-2101-0091 is common to both interface variants — one spare covers either configuration.

FAQ

Q1: Can A20B-2101-0091 replace A20B-2101-0090 (used in SVM1-4i)?

No. The A20B-2101-0090 serves the SVM1-4i (4A peak) while A20B-2101-0091 serves the SVM1-20i (20A peak). The current-carrying hardware inside each board is matched to its specific rating. They are not interchangeable even though they appear similar.

Q2: What safety procedure applies before accessing A20B-2101-0091?

The SVM1-20i module retains DC bus voltage after AC power removal. Wait for the charge indicator LED to extinguish and verify with a calibrated DC voltmeter before opening the module. Use an ESD-safe wrist strap when handling the board.

Q3: Does replacing A20B-2101-0091 require servo parameter re-entry?

No. Servo parameters are stored in the CNC's main memory, not in the drive PCB. After fitting the replacement, the CNC re-establishes communication and applies existing parameters automatically.

Q4: What symptoms indicate A20B-2101-0091 failure versus control board failure?

Power board failure: overcurrent alarms correlated with load, asymmetric motor phases, hardware protection trips under running conditions. Control board failure: FSSB/I/O Link communication errors, drive fails to reach ready state, erratic behaviour during initialisation. Load-correlated alarms point to the power board first.