Vibro-Meter MPC4 Modules

Technical Dossier

Product Details And Specifications

Vibro-Meter MPC4 Series: Comprehensive Module Range and Technical Overview

The Vibro-Meter MPC4 series is a line of Mechanical Protection Cards engineered for continuous machinery protection in heavy industrial environments. Manufactured by Vibro-Meter SA (Switzerland), these modules are deployed across critical rotating equipment monitoring systems in chemical plants, nuclear power stations, oil refineries, and offshore platforms worldwide. The MPC4 platform interfaces directly with proximity probes, velocity transducers, and accelerometers to provide real-time vibration, position, and speed monitoring with relay-based trip outputs. Its modular architecture allows integration into both standalone protection racks and distributed control system (DCS) backplanes, making it a standard reference in turbomachinery protection engineering.

The Evolution of MPC4 Architecture

The MPC4 designation covers a family of configurable mechanical protection cards developed by Vibro-Meter to replace earlier single-function analog protection relays. Early MPC4 variants used fixed-function analog signal conditioning with hardwired relay outputs, targeting turbine OEM protection panels from the 1980s and 1990s. Mid-generation variants introduced programmable threshold logic, dual-channel inputs, and ATEX-rated enclosure compatibility for hazardous area installations. Later configurations — identified by suffix codes such as SSS, 1Hh, and numeric range codes (e.g., 200-510) — define the measurement range, output relay configuration, and safety integrity level compliance. The MPC4 series reached its mature phase in the 2000s and is now in the sustained-support lifecycle stage. Vibro-Meter has transitioned new project specifications toward the VM600 platform, but MPC4 remains the installed base standard at thousands of sites globally. Backward compatibility between MPC4 sub-variants is limited by backplane connector pinout and firmware version; cross-referencing suffix codes is mandatory before substitution.

MPC4 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly referenced MPC4 series part numbers. Each module is classified by primary function:

Mechanical Protection Cards (Core Measurement & Trip Modules)

• MPC4 200-510-SSS-1Hh: Dual-channel vibration protection card, 200–510 mV range, single relay trip output, standard rack mount.
• MPC4 200-510-SSS-2Hh: Dual-channel vibration card, 200–510 mV range, dual independent relay outputs for redundant trip logic.
• MPC4 200-510-DDD-1Hh: Differential vibration measurement variant, 200–510 mV, single trip relay, for shaft differential expansion monitoring.
• MPC4 200-510-DDD-2Hh: Differential vibration, dual relay output, used in steam turbine axial position protection loops.
• MPC4 100-1000-SSS-1Hh: Extended range single-channel card, 100–1000 mV, for high-amplitude vibration environments such as compressor trains.
• MPC4 100-1000-SSS-2Hh: Extended range, dual relay, high-amplitude vibration protection with independent alert and danger thresholds.
• MPC4 200-510-PPP-1Hh: Proximity probe input variant, eddy-current sensor compatible, single relay, shaft radial position monitoring.
• MPC4 200-510-PPP-2Hh: Proximity probe input, dual relay, for X-Y radial vibration protection on journal bearing machines.
• MPC4 200-510-VVV-1Hh: Velocity transducer input card, seismic velocity measurement, single trip relay, used on large frame gas turbines.
• MPC4 200-510-VVV-2Hh: Velocity transducer input, dual relay, for bearing housing vibration monitoring per ISO 10816.
• MPC4 200-510-AAA-1Hh: Accelerometer input variant, high-frequency vibration detection, single relay, gearbox and rolling element bearing protection.
• MPC4 200-510-AAA-2Hh: Accelerometer input, dual relay, for high-frequency structural vibration monitoring in compressor applications.
• MPC4 200-510-SSS-1Hh-EX: ATEX-certified variant of the standard SSS card, intrinsically safe input barriers integrated, for Zone 1 hazardous area installations.
• MPC4 200-510-PPP-1Hh-EX: ATEX proximity probe card, Zone 1 rated, for shaft monitoring in explosive atmosphere environments.
• MPC4 200-510-TTT-1Hh: Speed/tacho input card, magnetic pickup or proximity probe compatible, overspeed and underspeed trip relay output.
• MPC4 200-510-TTT-2Hh: Dual-relay speed protection card, independent overspeed and underspeed trip channels, used in steam and gas turbine governor backup systems.
• MPC4 200-510-SSS-1Hh-SIL: SIL 2-rated variant, functional safety certified per IEC 61508, for safety instrumented system (SIS) integration.

Sourcing Hard-to-Find & Obsolete MPC4 Parts

The MPC4 series is no longer in active production at Vibro-Meter SA. OEM lead times for new-old-stock (NOS) units are extended or unavailable through standard distribution channels. DriveKNMS maintains a dedicated inventory of MPC4 modules sourced from decommissioned plant assets, authorized surplus channels, and tested pull-out stock. All units are individually serialized and traceable. DriveKNMS provides lifecycle extension support for MPC4 installations including cross-reference verification between suffix variants, firmware compatibility assessment, and drop-in replacement identification from the VM600 platform where applicable. For sites operating MPC4 racks under long-term service agreements, DriveKNMS can supply buffer stock on consignment to eliminate unplanned downtime risk.

Quality Control for the MPC4 Range

MPC4 modules present specific test challenges due to their analog signal conditioning front-ends, programmable threshold logic, and relay output circuits. DriveKNMS applies a structured test protocol for each MPC4 unit: (1) Visual inspection of backplane connector pins, relay contact surfaces, and PCB for corrosion, cold solder joints, or component drift. (2) Functional signal injection test — calibrated input signals are applied at the sensor input terminals across the full measurement range to verify linearity, threshold accuracy, and relay actuation at programmed setpoints. (3) Relay output verification — each trip relay is cycled under rated load to confirm contact resistance and operate/reset timing. (4) Insulation resistance test on all isolated I/O channels. (5) 24-hour burn-in at rated supply voltage. Units that pass all stages are issued a DriveKNMS test certificate with measured data and are returned to stock with original or equivalent protective packaging.