Mitsubishi Electric FR-A840-18.5K-1 FR-A800 Series Variable Frequency Drive

Description

Regulating three-phase induction and permanent magnet synchronous motors in heavy industrial networks is the primary function of the Mitsubishi Electric FR-A840-18.5K-1 variable frequency drive. This high-performance inverter from the elite FR-A800 series delivers an output capacity of 18.5 kW under Normal Duty (ND) conditions, offering superior speed and torque vector control. Operating on a 400V input voltage class, it integrates a specialized FM terminal configuration for high-speed pulse train monitoring. Embedded with standard RS-485, RS-422, and RS-232 serial interfaces, this unit supports smooth automation network integration while maintaining strict compliance with CE, UL, and cUL regulatory requirements.

Features

• Advanced Real Sensorless Vector Control and Full Vector Control when paired with encoder feedback.
• Built-in FM terminal configured for high-precision pulse train monitor output.
• Multiple integrated serial interfaces supporting RS-485, RS-422, and Modbus-RTU protocols as standard.
• Dual overload rating capacity: 150% overload for 60 seconds (Normal Duty) and 120% overload for 60 seconds (Light Duty).
• Integrated EMC filter reduces high-frequency electrical noise to enhance surrounding system reliability.
• Built-in safety-stop function compliant with EN ISO 13849-1 Category 3/PLd and IEC 61508 SIL2 standards.

Applications

• Heavy-duty extrusion and compounding systems.
• Industrial hoisting, crane long-travel, and overhead gantry systems.
• High-capacity positive displacement pumps and centrifugal fans.
• Metal wire drawing machines requiring precise tension control.
• Automated materials handling conveyors and sorting lines.

Technical Specifications

Empirical Engineering Insights

Alternative Models & Compatibility

This unit replaces legacy FR-A740-18.5K models. While physical mounting footprints are highly similar, wiring layouts and the digital keypads differ. Use Mitsubishi's FR Configurator2 software to import existing FR-A700 parameter profiles and convert them directly to FR-A800 compatible formats. Ensure that terminal "FM" (pulse output) configuration is matched, as the alternative "AM" (analog voltage) variant has distinct hardware wiring requirements.

Application Pitfalls & Engineering Notes

The FR-A840-18.5K-1 features dual overload ratings: Normal Duty (ND) and Light Duty (LD). For heavy cyclic applications like escalators or reciprocating compressors, keep parameter settings configured to ND (150% overload capacity). Operating in LD mode (22 kW output) on heavy torque loads will trigger premature E.THT (Inverter Overload) or E.OC1 (Overcurrent during acceleration) trip states. Ensure minimum clearance guidelines (100 mm top and bottom) are strictly maintained inside electrical panels to ensure proper heat sink thermal convection.

Commissioning & Wiring Tips

The FM feedback loop is susceptible to electromagnetic interference (EMI). Run all pulse monitoring cables in dedicated grounded steel conduits or use shielded twisted-pair (STP) lines. Ground the shield exclusively at the drive’s protective earth terminal (PE) and avoid routing control wires parallel to high-power motor cables (U, V, W) to prevent noise induction on the pulse train signals.

Installation Guidelines