MCG BMC12H-INV Brushless Servo Amplifiers: B25A40ACH-MC1, B25A40ACL-MC1, B25A40ACK-MC2

Technical Dossier

Product Details And Specifications

MCG BMC12H-INV Series: Comprehensive Module Range and Technical Overview

The MCG BMC12H-INV series of brushless servo amplifiers represents a mature, field-proven drive platform deployed extensively across heavy industrial sectors including petrochemical processing, nuclear power auxiliary systems, offshore drilling rigs, and continuous-process refinery operations. MCG (Motion Control Group), operating under the Regal Beloit / Rexnord industrial drive umbrella, engineered the BMC12H-INV line to deliver closed-loop brushless DC servo control with integrated inverter topology, targeting applications where precise torque regulation, high-cycle duty, and long MTBF are non-negotiable. Installed base across North American and European process industries remains substantial, making reliable spare parts sourcing a critical operational requirement for maintenance engineers managing aging but still-productive machinery.

The Evolution of BMC12H-INV Architecture

The BMC12H-INV platform was developed during the late 1980s through the 1990s as a response to industrial demand for compact, rack-mountable brushless servo drives capable of replacing legacy DC brush amplifiers without full mechanical redesign. Early variants in the BMC series used analog command interfaces (±10 V differential) and relied on resolver feedback exclusively. The MC1 sub-designation (e.g., B25A40ACH-MC1, B25A40ACL-MC1) introduced enhanced current-loop bandwidth and improved thermal management over the base MC revision, extending continuous duty ratings in high-ambient enclosures. The MC2 sub-designation (B25A40ACK-MC2) further refined the PWM switching frequency and EMI filtering to comply with evolving CE and UL industrial standards.

The naming convention decodes as follows: B = Brushless amplifier family | 25 = 25A peak current rating | A40 = 40 VDC bus voltage class | AC = AC input rectification | H/L/K = hardware revision suffix | MC1/MC2 = mechanical/control board revision level | BMC12H-INV = base chassis/inverter module designation. Compatibility between MC1 and MC2 control boards and the BMC12H-INV chassis is revision-dependent; cross-substitution requires verification of firmware and feedback interface matching.

As the BMC12H-INV series has entered the obsolescence phase, MCG no longer manufactures new units. OEM replacement pathways include the Regal Beloit Unidrive M series and select Kollmorgen AKD drives, but mechanical and electrical retrofit costs are significant. For facilities committed to maintaining existing machinery, sourcing tested surplus and refurbished BMC12H-INV units remains the most cost-effective lifecycle extension strategy.

BMC12H-INV Full Catalog & Functionalities (SKU List)

The following SKUs represent verified models within the MCG BMC12H-INV brushless servo amplifier family, organized by control revision and current class:

Inverter Chassis / Base Amplifier Modules

• B25A40ACH-MC1: 25A peak, 40V bus, AC input, H-revision, MC1 control board, resolver feedback
• B25A40ACL-MC1: 25A peak, 40V bus, AC input, L-revision, MC1 control board, low-inductance motor optimized
• B25A40ACK-MC2: 25A peak, 40V bus, AC input, K-revision, MC2 control board, enhanced EMI filter
• B12A40ACH-MC1: 12A peak, 40V bus, AC input, H-revision, MC1 control board, standard resolver interface
• B12A40ACL-MC1: 12A peak, 40V bus, AC input, L-revision, MC1 control board, compact form factor
• B12A40ACK-MC2: 12A peak, 40V bus, AC input, K-revision, MC2 control board, updated PWM topology
• B50A40ACH-MC1: 50A peak, 40V bus, AC input, H-revision, MC1 control board, high-torque servo applications
• B50A40ACK-MC2: 50A peak, 40V bus, AC input, K-revision, MC2 control board, improved thermal dissipation
• B25A80ACH-MC1: 25A peak, 80V bus, AC input, H-revision, MC1 control board, higher voltage servo systems
• B25A80ACL-MC1: 25A peak, 80V bus, AC input, L-revision, MC1 control board, 80V bus low-inductance variant
• B25A80ACK-MC2: 25A peak, 80V bus, AC input, K-revision, MC2 control board, CE-compliant 80V class
• B12A80ACH-MC1: 12A peak, 80V bus, AC input, H-revision, MC1 control board, resolver feedback standard
• B50A80ACK-MC2: 50A peak, 80V bus, AC input, K-revision, MC2 control board, high-power 80V platform
• BMC12H-INV: Base inverter chassis module, accepts MC1/MC2 control boards, field-replaceable design
• BMC12H-INV/PS: Inverter chassis with integrated power supply section, single-enclosure configuration
• BMC12H-CB: Replacement control board assembly for BMC12H-INV chassis, MC1-compatible
• BMC12H-CB-MC2: Replacement control board assembly for BMC12H-INV chassis, MC2-compatible

Sourcing Hard-to-Find & Obsolete BMC12H-INV Parts

DriveKNMS maintains a dedicated inventory program for discontinued MCG BMC12H-INV series components. As MCG has ceased production of the BMC12H-INV platform, procurement through standard distribution channels is no longer viable. DriveKNMS sources units through verified industrial surplus networks, decommissioned plant auctions, and direct OEM overstock channels, applying full functional testing before any unit enters available inventory.

For facilities operating under long-term service agreements or regulated maintenance schedules (common in nuclear auxiliary systems and refinery SIS loops), DriveKNMS offers consignment stocking arrangements and priority reservation for critical spare quantities. Requests for multiple units, matched revision sets, or specific date-code ranges are accommodated. Customers are encouraged to submit full BOM lists for cross-reference and availability confirmation.

Quality Control for the BMC12H-INV Range

Each BMC12H-INV unit processed by DriveKNMS undergoes a structured inspection and functional test protocol specific to the amplifier's architecture. The test sequence includes: incoming visual inspection for PCB corrosion, capacitor bulge, and connector wear; static resistance checks on the IGBT/MOSFET inverter bridge; power-on sequencing under current-limited bench supply to verify control board initialization and fault code output; closed-loop servo test using a matched brushless motor and resolver simulator to confirm velocity loop stability, current limit response, and enable/disable logic; and final thermal soak at rated continuous current for a minimum of 30 minutes to validate thermal management integrity. Units exhibiting marginal performance on any parameter are either repaired to OEM specification or rejected from inventory. Test records are retained and available upon request for regulated-industry customers.