POWER SUPPLY MODULE A06B-6110-H026 A06B6110H026 AO6B-611O-HO26

Fanuc A06B-6110-H026 | Alpha i Power Supply Module PSM-26i (aiPS-26) — 29.8kW, 200–240V AC 3-Phase, 106A, 283–339V DC Bus, Active Regeneration — Replaced by A06B-6140-H026

Overview

The Fanuc A06B-6110-H026 is the PSM-26i — the 29.8kW power supply module in Fanuc's first-generation alpha i (A06B-6110) power supply series.

It holds the same position in the alpha i drive system that the PSM-26 (A06B-6087-H126) holds in the original alpha system: the mid-range power supply that covers the most common machine configuration, where a mid-power spindle and multiple servo axes draw simultaneous power within the 29.8kW continuous envelope.

The distinction between the A06B-6110 alpha i series and the A06B-6087 alpha series is architectural, not merely generational. These two module families serve fundamentally different drive system generations.

The A06B-6087 PSM-26 powers the original alpha SVM amplifiers (A06B-6079, A06B-6096 series) and the original alpha SPM spindle amplifiers. 

The A06B-6110-H026 PSM-26i powers the alpha i SVM amplifiers (A06B-6114 series) and the alpha i SPM spindle amplifiers (A06B-6120 series) — modules that communicate with 16i/18i/0i CNC controls via the FSSB optical servo bus rather than the older Type A/B electrical interface.

A CNC machine cannot substitute one family's power supply for the other's; the DC bus architecture and control power distribution circuits are different.

The A06B-6110-H026 is the first generation of the alpha i power supply, and it has been replaced in the active Fanuc product line by the A06B-6140-H026 — the second-generation equivalent. Both modules serve the same alpha i drive system, deliver the same 29.8kW output class, and maintain compatibility with the same downstream A06B-6114 SVM and A06B-6120 SPM amplifiers.

The transition from H026 to H140-H026 brought revised board designs and improved component longevity, but machines running A06B-6110-H026 modules continue to operate on active support from the specialist aftermarket.

Key Specifications

Alpha i vs Alpha — What the Generation Change Delivered

The transition from the original alpha drive system to the alpha i generation brought improvements that mattered to machine builders and operators: higher encoder resolution in the motors (from 65,536 to 1,000,000 and eventually 16,000,000 counts per revolution), FSSB fiber optic communication replacing the older electrical servo interfaces, higher servo loop bandwidth enabling tighter following error performance, and improved IPM transistor technology in the amplifiers.

The power supply module's role in delivering these improvements is indirect but essential — the A06B-6110-H026 provides the DC bus that the improved alpha i SVM and SPM amplifiers depend on.

The PSM-26i's 283–339V DC bus output range is slightly wider on the upper end than the original PSM-26's 283–325V. This reflects refined power supply regulation in the alpha i generation, providing more headroom for regenerative energy handling before overvoltage protection needs to intervene.

The power factor correction above 0.98 is also a meaningful engineering improvement — the original alpha PSM series operated at lower power factors, and the harmonic current content returned to the facility supply was higher.

The PSM-26i's PFC circuit presents a nearly unity power factor load to the three-phase supply, which reduces the apparent power demand relative to the real power consumed, and reduces harmonic distortion on the facility supply bus.

Dual Fan Monitoring — AL-2 and AL-A

The A06B-6110-H026 is one of the few alpha family power supply modules with a separate alarm code for the external heatsink fan (AL-A) in addition to the internal fan alarm (AL-2). This distinction is operationally significant:

AL-2 — Internal cooling fan (A90L-0001-0441#39) stopped. The internal fan manages airflow within the module housing, cooling the control board and power electronics. AL-2 requires immediate fan replacement.

AL-A — External cooling fan (A90L-0001-0509) stopped. The external fan is mounted on the heatsink and draws air through the fins to remove heat from the IGBT transistor modules. Without the external fan, the heatsink temperature climbs toward AL-3 (over-temperature) shutdown.

AL-A also warrants immediate fan replacement.

Distinguishing between AL-2 and AL-A on the module's display allows a maintenance technician to identify which fan has failed without opening the module — AL-2 means the internal fan, AL-A means the external heatsink fan.

Both fans are separately available as spare parts and can be replaced without exchanging the complete module.

Leakage Detection and Regeneration Efficiency

The built-in leakage detection circuit monitors for ground fault currents in the DC bus and connected motor wiring. In the alpha i system, the higher encoder resolution and tighter servo performance of A06B-6114 SVM modules means that minor position errors and velocity irregularities caused by motor winding insulation degradation become visible at the CNC before a complete winding failure occurs.

The leakage detection circuit provides the power-stage early warning that complements this — detecting the current path forming to ground as insulation breaks down.

The >0.98 power factor correction means the A06B-6110-H026 draws current from the three-phase supply in a nearly sinusoidal waveform, closely in phase with the supply voltage. From the facility's power infrastructure perspective, this means the apparent power (kVA) drawn by the PSM-26i is very close to the real power (kW) it actually consumes.

This matters for industrial facilities with power factor penalties in their electricity tariff, and for generator-powered installations where reactive current capability is limited.

FAQ

Q1: Can the A06B-6110-H026 replace an A06B-6087-H126 (PSM-26, alpha series) if the older module has failed?

No. The alpha (A06B-6087) and alpha i (A06B-6110) power supply modules are not interchangeable.

The control power distribution architecture and DC bus interface between the PSM and the SVM/SPM amplifiers differ between generations. 

The A06B-6110-H026 is designed to operate with A06B-6114 SVM and A06B-6120 SPM amplifiers; the A06B-6087-H126 operates with A06B-6079/6096 SVM and A06B-6088/6102 SPM amplifiers.

A machine running original alpha amplifiers must use the original alpha PSM family.

Q2: The A06B-6110-H026 has been replaced by the A06B-6140-H026 — is the H026 still adequate for an operational machine, or should it be upgraded to the H140?

The A06B-6110-H026 is fully adequate for machines it currently serves — it delivers the same 29.8kW output, maintains the same 283–339V DC bus, and supports the same A06B-6114/A06B-6120 amplifier families as the replacement A06B-6140-H026.

The H140 is the current production designation with revised internal board designs for improved longevity, but it is not a functional upgrade in any meaningful operational sense for a machine running correctly with the H026.

When the H026 eventually requires replacement, the H140 is the natural successor and is plug-compatible with the same drive rack.

Q3: What CNC alarm appears on a 16i or 18i control when the PSM-26i develops a fault?

The alpha i power supply module alarms appear on the module's front panel display as AL-1 through AL-7 and AL-A, AL-E. On the CNC screen, the corresponding alarm presentation depends on whether the fault also causes the connected SVM or SPM modules to alarm.

If the PSM bus collapses (AL-4, voltage drop) or the PSM shuts down, all connected servo axes lose power and SV-0401 (servo amplifier disconnect) or SP alarms (spindle disconnect) appear simultaneously for all axes — this pattern of simultaneous alarms across all axes is itself diagnostic of a PSM-level fault rather than an individual axis amplifier fault.

Check the PSM front panel display directly for the specific PSM alarm code.

Q4: What facility electrical provisions are needed for the A06B-6110-H026's 106A rated input?

A 106A continuous rated input at 200V requires a circuit breaker rated for 125–150A, with a tripping characteristic that accommodates the startup inrush transient without nuisance operation. Cable cross-section for 106A at the installation's ambient temperature must comply with relevant electrical standards.

An AC reactor appropriate for this current class is recommended to limit harmonic current injection and reduce startup inrush. 

The facility transformer feeding this circuit should have adequate capacity for the 29.8kW real power demand plus the reactive power drawn during startup.

Q5: Can the A06B-6110-H026 power the beta i servo amplifier units (A06B-6130 series) in addition to the alpha i SVM modules?

Beta i servo amplifier units (A06B-6130 series) have their own self-contained power supplies and do not draw from the main PSM DC bus — they connect directly to an AC supply and generate their own internal DC bus.

The alpha i PSM-26i bus supplies only the A06B-6114 alpha i SVM and A06B-6120 alpha i SPM modules. Beta i units are connected to the CNC's FSSB chain alongside the alpha i amplifiers but powered independently. 

The A06B-6110-H026 does not need to be sized or selected based on any beta i unit's power demand.