FANUCA06B-6057-H004Single-Axis Digital AC Servo Amplifier Unit, 185 V Input Type, for Model 0S / 5S Motors

Product Description

What this part is

A Fanuc A06B-6057-H004 digital AC servo amplifier unit — a single-axis drive from Fanuc’s first generation of digital AC servo amplifiers. It takes a PWM serial command from a digital Fanuc CNC and drives one AC servo motor, closing the current and velocity loops in the drive itself. This is the amplifier normally paired with Fanuc AC servo motor models 0 and 5 (the 0S / 5S series) on lathes and machining centres.

Construction is an anodised metal frame with an open wiring section, and the intelligence is the control PCB A16B-1200-0670 fitted inside. This is a complete amplifier unit — not a bare board.

Decoding the order code

A06B – Fanuc drive and motor prefix, covering servo amplifiers, spindle amplifiers and motors.6057 – the drive family. The 6050 / 6057 / 6061 groups are Fanuc’s first digital AC servo and velocity-control generation, using the PWM serial interface from the CNC.-H – and this is the field that decides what arrives in the crate. In Fanuc A06B numbering an H suffix denotes a complete unit; a J suffix denotes a service part or component of that unit, typically a board. Buying an H-number gets you an amplifier; buying a J-number gets you a PCB. This is an H-number, so it is the amplifier.004 – the specific build within the family. On the 6057 group the build number sets the axis count and the input voltage class: -H004 is the single-axis, 185 V input type, whereas -H201 in the same family is a two-axis unit of the same voltage class.

Published specifications

Type: digital AC servo amplifier unit, PWM serial interface from CNCAxes: single axisInput type: 185 V classMotor pairing: Fanuc AC servo motor model 0 / 5 series (0S, 5S)Internal control PCB: A16B-1200-0670Construction: anodised metal frame, open wiring section

What these specs mean in practice

Axis count is the trap on this family. The 6057 group contains single-axis and multi-axis builds that look broadly similar and mount in the same way; the build number is the only reliable way to tell them apart. An -H004 will run one axis. If your machine has a two-axis 6057 in that position, this is the wrong unit — look for the 2-axis build instead.

The 185 V input type also matters: these amplifiers are fed from a dedicated servo transformer, not straight off the mains, and the transformer secondary has to suit the amplifier’s voltage class. And because this generation is parameter-set from the CNC rather than by pots on the drive, the CNC servo parameters and the motor ID must be right for the motor you actually have fitted. A mismatched motor ID is the commonest reason a good drive alarms on first power-up.

What is not included

Amplifier unit only. This listing does not include the servo motor, the pulse coder or resolver, the servo transformer or line reactor, PWM command cables, feedback cables, motor power cabling, connector or terminal-block kits, the mounting plate or cabinet hardware, fuses, a braking or regeneration resistor unit, spare control or power boards, or any CNC parameters, servo software or documentation. It is one amplifier, not a drive package and not a donor kit.

Quantity and configuration

Sold as 1 piece — one single-axis servo amplifier unit. Takeout, tested, in an opened box.

Installation and setup notes

Servo amplifiers hold a lethal charge in the DC link after power-off. Isolate, lock out and confirm the bus is discharged before touching the terminals or opening the wiring section. Check the servo transformer secondary voltage against the amplifier’s 185 V class before energising. Back up CNC servo parameters, confirm the motor ID matches the motor fitted, and on first power-up run the axis with the machine clear, the travel limits verified and the emergency stop within reach. If the unit has been stored for a long period, bring it up gently to re-form the DC link capacitors rather than energising at full voltage from cold.

Interchange guidance

Searchable equivalents of the same part: A06B-6057-H004, A06B6057H004, A06B 6057 H004, A06B-6057H004. Related but not interchangeable: A06B-6057-H201 (two-axis build of the same family) and other -H0xx builds in the 6057 group, which differ in axis count or voltage class. A06B-6057-J0xx numbers are service parts — boards and components, not amplifiers — so they are not substitutes for this unit either.