Mitsubishi Electric FR-A840-3.7K-1 FR-A800 Variable Frequency Drive

SKU FR-A840-3.7K-1

Disponibile

12-month warranty
Free returns within 30 days

Manufacturer: Mitsubishi Electric
Product No.: FR-A840-3.7K-1
Origin United States
Product Type: Variable Frequency Drives
Payment: T/T, Western Union
Weight: 4.5 kg
Shipping port: Xiamen
Warranty: 12 months

Product Description

Description

Engineered to deliver exceptional motor control performance, the Mitsubishi Electric FR-A840-3.7K-1 is a highly versatile three-phase 400V class variable frequency drive from the robust FR-A800 series. Designed for demanding heavy industrial applications, this inverter provides precise speed and torque regulation with an output rating of 3.7 kW and an output current of 9 A. Integrated serial communication protocols make this drive highly compatible with diverse automation architectures.

Key Features

Real sensorless vector control and advanced magnetic flux vector control for precise low-speed torque.
Embedded RS-485, RS-422, and RS-232 serial ports for seamless communication.
Inherent energy-saving algorithms optimizing efficiency in fan and pump networks.
Compliance with international functional safety standards including CE, UL, and cUL.

Industrial Applications

Conveyor and material handling networks requiring strict speed profiles.
Industrial fans, centrifugal pumps, and secondary aeration blowers.
Mixers, extruders, and packaging machinery needing robust starting torque.

Technical Specifications

Parameter	Specification
Manufacturer	Mitsubishi Electric
Model Number	FR-A840-3.7K-1
Series	FR-A800 Series
Applicable Motor Capacity	3.7 kW
Input Voltage Class	Three-phase 400 V Class
Output Voltage	Three-phase 380 to 500 V
Output Rated Current	9 A
Output Capacity	6.9 kVA
External Communication	RS-232 / RS-422 / RS-485
Certifications and Standards	CE, UL, cUL
Width	150 mm
Height	260 mm
Depth	140 mm
Shipping Weight	4.5 kg

Control Terminal Connections

Terminal Symbol	Terminal Function & Description
STF	Forward Rotation Start (Short STF-SD to start forward rotation, open to decelerate to stop)
STR	Reverse Rotation Start (Short STR-SD to start reverse rotation, open to decelerate to stop)
SD	Common Terminal for Contact Inputs (Isolated from circuit common)
PC	24 VDC Power supply output / External transistor common terminal
10, 2, 5	Frequency Setting Voltage Analog Inputs (0 to 5 VDC, 0 to 10 VDC)
4, 5	Frequency Setting Current Analog Inputs (4 to 20 mADC)
A, B, C	Relay Contact Alarm Output (Indicates drive fault protection activation)

Empirical Engineering Insights

Alternative Models & Compatibility

The drive functions as a modern replacement for legacy FR-A740-3.7K units. While installation dimensions align closely, control terminal spacing and auxiliary terminal mappings should be verified. Users looking to load parameter files from older iterations should use FR Configurator2 software to ensure non-compatible parameters are modified prior to deployment.

Application Pitfalls & Engineering Notes

Operating at carrier frequencies higher than 12 kHz may trigger thermal-related current derating. If motor cable distances exceed 30 meters, high-frequency voltage spikes (reflected waves) can degrade motor insulation. In such layouts, installing a dV/dt or output reactor is necessary to safeguard the system.

Commissioning & Wiring Tips

Always ground the drive chassis to a dedicated earth terminal using a low-impedance conductor. Route all low-voltage analog control wiring (such as 0-10V or 4-20mA signals) through shielded twisted-pair cabling, separating them from high-voltage motor and input power leads by a minimum of 100 mm to suppress noise coupling.

Installation Guidelines

CRITICAL WARNING: Hazardous voltage levels remain present inside the drive capacitor bank even after mains isolation. De-energize all primary and auxiliary power lines. Allow a minimum of 10 minutes for electrical discharge, then verify the DC bus voltage across terminals P/+ and N/- is below 45 VDC using a calibrated voltmeter before handling terminal connections.

1 Securely mount the inverter vertically on a flat, non-flammable surface to facilitate proper airflow through the heat sink channels.
2 Wire the input power supply lines to input terminals R/L1, S/L2, and T/L3. Connect motor phases directly to output terminals U, V, and W. Do not connect AC mains power to output terminals.
3 Terminate control inputs and verify appropriate digital logic sink/source parameters are matched by positioning the internal slide switch correctly.

Shipping & Returns

Global Express Shipping

Standard Delivery: 4–6 business days via DHL, FedEx, and UPS.
Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
Worldwide Coverage: Serving over 150 countries.

Returns & Warranty

30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
12-Month Warranty: Every industrial component is backed by our technical warranty.

FAQ

What is the primary communication configuration supported by this variable frequency drive?

It features integrated RS-485, RS-422, and RS-232 serial interfaces supporting Modbus RTU communication protocols for direct link to industrial PLCs and HMIs.

Can this drive be used with standard induction motors and PM motors?

Yes, it supports multiple motor types through advanced control algorithms, including standard induction motors and permanent magnet (PM) motors.

What safety standards and regulatory approvals does the unit carry?

The drive is compliant with CE, UL, and cUL international standards, meeting requirements for demanding industrial deployments.

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