C Series C Power Supply Module A06B-6077-H111 A06B6077H111 AO6B-6O77-H111

Fanuc A06B-6077-H111 | Alpha Servo Power Converter PSM-11 — 13.2kW, 200–230V AC 3-Phase, 49A Input, 283–325V DC Bus, Active Regeneration, External Forced Cooling Required

Overview

The Fanuc A06B-6077-H111 is the PSM-11 — the larger of the two power supply modules in the A06B-6077 series, delivering 13.2kW of DC bus power to the alpha series drive system. While the rest of the alpha PSM family lives in the A06B-6087 numbering block, the PSM-11 occupies its own A06B-6077 series alongside the smaller PSM-5.5 (A06B-6077-H106).

Both are structurally similar to the higher-power A06B-6087 PSM modules — active regeneration front end, three-phase input, DC bus output in the 283–325V range — but they serve a distinct machine size segment: compact machining centres, CNC lathes, and small multi-axis machines where the combined spindle and servo power demand fits comfortably within 13.2kW.

At 13.2kW output and 49A rated input, the PSM-11 is well-matched to small alpha spindle amplifier modules paired with one or two servo axis SVM modules.

A machine with a 3.7kW or 5.5kW spindle motor and two or three small alpha servo axes is a typical PSM-11 installation — total simultaneous power demand well within the 13.2kW ceiling, with adequate margin for the transient peaks during multi-axis acceleration.

Machines running Series 0-C or 0-D controls with compact alpha drive systems are among the most common PSM-11 applications; these control generations were designed for smaller, economical machine tools where the PSM-11's power class is the natural fit.

The PSM-11 shares a specific characteristic with the PSM-45 and PSM-55 at the other end of the power scale: it requires external forced air cooling.

This is explicitly noted in Fanuc's alpha series configuration documentation alongside the PSM-45, distinguishing both modules from the PSM-15 through PSM-37 range that are self-cooled through their own built-in fan and heatsink arrangement.

For the PSM-11, the external forced cooling requirement reflects the module's compact physical format: the 60mm wide housing does not accommodate the heatsink fin area that would be needed for self-cooling at 49A input, so the thermal design depends on the cabinet providing supplementary airflow across the module's heatsink.

Active regeneration is part of the PSM-11's design, which places it in the PSM family rather than the PSMR (resistor discharge) alternative.

Even at 13.2kW, the deceleration energy from small spindle and servo motors adds up across a production shift of repeated positioning cycles and tool changes.

The PSM-11 returns this energy to the three-phase supply rather than burning it in resistors, eliminating both the need for an external discharge resistor unit and its associated cabinet heat generation.

Key Specifications

A06B-6077 Series — Small Machine Power Architecture

The A06B-6077 product family was developed alongside the main A06B-6087 PSM series to address the small machine segment without overspecifying the power supply.

A machine tool builder designing a compact CNC lathe or small drilling centre with 5–10kW of total drive system power had no need for the 17.5kW PSM-15's capacity, and the 60mm wide housing of the PSM-11 (versus the 90–150mm housings of the A06B-6087 modules) fits more naturally in the compact electrical cabinets of small machine tools.

The A16B-2202-0461 wiring board and A16B-2202-0420 control card inside the PSM-11 are specific to the A06B-6077 series and are not interchangeable with the boards in the A06B-6087 PSM-15 through PSM-55.

This has a practical implication for maintenance: spares sourcing for the PSM-11's internal boards follows the 6077 part number structure, and these boards are not available separately — the module is the service unit.

Compact Format, External Cooling Trade-Off

The PSM-11's ~2.26kg weight and compact 60mm-wide housing are practical advantages for small machine electrical cabinet layout. A cabinet that would be overwhelmed by the 150mm PSM-15 can accommodate the PSM-11 without space constraints.

This compactness is achieved partly by removing the self-cooling heatsink and fan arrangement that the larger PSM modules rely on — the PSM-11 depends on the cabinet's airflow to provide cooling across its heat-generating components.

In practice, this means the PSM-11 must be mounted in a location within the cabinet where cabinet airflow is positive and consistent, or where a dedicated airflow arrangement directs cool air across the module.

A cabinet with poor thermal design — hot zones, recirculated air, or blocked ventilation — will produce AL03 heatsink over-temperature shutdowns on the PSM-11 even at load levels well below 13.2kW.

This is a more common maintenance problem on small machines than on large ones, because small machines are more likely to have minimal cabinet airflow provisions.

Leakage Detection and Alarm System

The A06B-6077-H111 includes a leakage detection circuit that monitors for ground fault conditions in the DC bus and downstream motor wiring.

This provides early warning of deteriorating motor winding insulation — a ground fault current that builds gradually rather than appearing suddenly will trigger the leakage detection before it develops into a complete winding failure or a tripped circuit breaker. 

The alarm code system for the PSM-11 follows the standard alpha PSM alarm structure:

AL01 — Overcurrent in the main power module (IPM fault on PSM-11, distinct from the overcurrent meaning on PSM-15 and above).

AL02 — Cooling fan stopped. On the PSM-11, the specific fan affected should be identified and replaced promptly.

AL04 — DC link voltage drop. Check downstream amplifier modules and DC bus connections. 

AL05 — DC bus pre-charge did not complete. Investigate the pre-charge circuit within the module.

FAQ

Q1: The PSM-11 is in the A06B-6077 series rather than A06B-6087 — does this mean it is incompatible with A06B-6087 SVM servo amplifier modules on the same bus?

No, series numbering in the A06B product system identifies the specific module type rather than a system incompatibility.

The A06B-6077-H111's DC bus output is fully compatible with A06B-6079 and A06B-6096 series SVM servo amplifier modules and A06B-6088/A06B-6102 SPM spindle amplifier modules on the shared DC bus.

The PSM-11 simply sits at the low-power end of the alpha family, providing the same regulated 283–325V DC bus that all alpha series amplifier modules require, at a current capacity appropriate for small machine configurations.

Q2: For the PSM-11's external forced cooling requirement, what specific airflow arrangement does Fanuc recommend?

Fanuc's alpha series hardware installation manual (B-65162) documents the forced cooling arrangements for modules that require it, including the PSM-11.

The requirement is for cool external air to flow across the module's heatsink surfaces — typically from the bottom of the module toward the top, following natural convection direction. 

The specific airflow volume and velocity required are functions of the module's heat generation at rated load and the heatsink's thermal resistance.

In practice, a small axial fan mounted to direct airflow across the PSM-11's heatsink faces, sized according to the B-65162 specification, is the standard implementation.

Q3: Can the PSM-11 replace the PSM-5.5 (A06B-6077-H106) in a machine where the PSM-5.5 has failed?

A PSM-11 can supply the same DC bus that a PSM-5.5 served, and the additional power capacity (13.2kW vs 5.5kW) poses no risk to the downstream amplifiers — they will draw only what they need.

The physical installation requires verifying that the PSM-11 fits the available space (same 60mm width for both units) and that the facility supply circuit can provide the PSM-11's 49A rated input versus the PSM-5.5's lower current.

If the supply circuit was sized to the PSM-5.5's requirements, upgrading to the PSM-11 requires confirming the circuit protection and wiring are adequate for 49A.

Q4: The product description includes "servo power converter" in the part listing — what does this designation mean in the Fanuc alpha system context?

Fanuc's Radwell and other distributor listings describe the A06B-6077-H111 as a "servo power converter" because its primary function is converting three-phase AC supply power to the DC bus that drives servo (and spindle) motor amplifiers.

The "converter" terminology reflects the module's role in the system's power architecture — it is the AC-to-DC conversion stage.

This is not a different product from the PSM-11; "servo power converter," "PSM-11," and "power supply module" all describe the same A06B-6077-H111 unit from different descriptive angles.

Q5: After a PSM-11 replacement, what startup verification is needed on the CNC?

Power on the CNC and observe the PSM-11's front panel LED status. The module should show a normal operating state (bus charged, no alarm) within the first several seconds after power application.

Confirm the DC bus voltage is present and within the 283–325V range by checking the SVM module status displays on the CNC's servo maintenance screen.

If any alarm appears on the PSM-11 or on downstream SVM modules immediately at startup, diagnose before running any axis. If startup is clean, verify normal axis operation with a slow manual jog on each axis before returning the machine to automatic cycle.