Mitsubishi MELSEC-K Series Modules | K62P Power Supply Unit

Technical Dossier

Product Details And Specifications

Mitsubishi MELSEC-K Series: Comprehensive Module Range and Technical Overview

The Mitsubishi MELSEC-K Series is a mid-range programmable logic controller platform developed by Mitsubishi Electric for deployment in heavy industrial environments. It has accumulated significant installed base across petrochemical complexes, nuclear auxiliary systems, refinery process control loops, and large-scale discrete manufacturing lines. The K Series occupies the architectural tier between the earlier MELSEC-A Series and the later MELSEC-Q Series, providing a stable, rack-based control infrastructure that remains operational in thousands of facilities globally. Its continued presence in aging plant infrastructure makes lifecycle parts sourcing a critical operational requirement for maintenance engineers and procurement teams.

The Evolution of MELSEC-K Series Architecture

The MELSEC-K Series was introduced by Mitsubishi Electric as a successor to the MELSEC-A Series, incorporating an enhanced backplane bus architecture capable of higher I/O throughput and improved noise immunity for industrial environments. The platform uses a proprietary parallel bus structure across its base units, with module slots governed by a fixed addressing scheme that differs from the later MELSEC-Q Series' dynamic slot assignment model.

Early K Series deployments used discrete wiring for I/O termination. Later revisions introduced connector-type terminal blocks and compatibility with MELSEC-NET/MINI-S3 network adapters, enabling limited distributed I/O configurations. The series does not natively support CC-Link or PROFIBUS, which creates integration constraints when interfacing with modern field devices. Engineers maintaining K Series installations must account for this protocol gap when planning system expansions or hybrid architectures.

The MELSEC-K Series has entered the end-of-life phase. Mitsubishi Electric has formally discontinued production of most K Series modules. The recommended migration path is to the MELSEC-Q Series or MELSEC-iQ-R Series, both of which offer backward-compatible programming environments via GX Works2 and GX Works3. However, full migration carries significant re-engineering cost, making long-term spare parts support the preferred strategy for the majority of existing K Series installations.

MELSEC-K Series Full Catalog & Functionalities (SKU List)

Power Supply Modules

• K62P: AC100–240V input power supply unit for K Series base units, 5VDC output, standard rack mount form factor.
• K61P: DC24V input power supply module, designed for installations with DC-only power infrastructure.
• K63P: High-capacity power supply unit supporting extended I/O rack configurations with increased current output.

CPU Modules

• K3CPU: Base CPU module for MELSEC-K Series; supports ladder diagram programming via MEDOC or GX Developer.
• K3NCPU: Enhanced CPU with expanded program memory capacity and faster scan cycle performance.
• K7CPU: High-performance CPU module with extended data register capacity for complex process applications.
• K7NCPU: Network-capable CPU variant supporting MELSEC-NET/MINI-S3 peer-to-peer communication.

Digital Input (DI) Modules

• K1X16D: 16-point DC24V digital input module, sink/source selectable, standard density I/O.
• K1X32D: 32-point DC24V digital input module for high-density discrete signal acquisition.
• K1X16A: 16-point AC100–120V digital input module for legacy field device compatibility.

Digital Output (DO) Modules

• K1Y16T: 16-point transistor output module, NPN open-collector, DC24V load, 0.5A per point.
• K1Y32T: 32-point transistor output module for high-density actuator control applications.
• K1Y16R: 16-point relay output module, 2A per point, suitable for AC/DC mixed load environments.

Analog I/O Modules

• K2AD4: 4-channel analog input module, 12-bit resolution, 4–20mA / 0–10V selectable input range.
• K2DA2: 2-channel analog output module, 12-bit resolution, current and voltage output modes.

Communication & Network Modules

• K6ADP: MELSEC-NET/MINI-S3 network adapter module for K Series master/slave token-ring configurations.
• K6RS4: RS-422/RS-485 serial communication module for SCADA and HMI interface connections.

Sourcing Hard-to-Find & Obsolete MELSEC-K Series Parts

DriveKNMS maintains a dedicated inventory program for discontinued Mitsubishi MELSEC-K Series components. As Mitsubishi Electric has ceased production of the K Series platform, the secondary market is the primary procurement channel for replacement modules. DriveKNMS sources K Series parts through verified industrial surplus channels, decommissioned plant equipment, and authorized distributor overstock.

All sourced units are subject to pre-sale inspection covering physical condition, connector integrity, and where applicable, functional power-on verification. For CPU and communication modules, firmware version documentation is provided where retrievable. DriveKNMS maintains stock records for the most frequently requested K Series SKUs and can respond to emergency procurement requests within 24 hours. For obsolete models with no available stock, DriveKNMS provides cross-reference guidance to compatible MELSEC-Q Series equivalents and can assist with migration bill-of-materials preparation.

Quality Control for the MELSEC-K Series Range

MELSEC-K Series modules present specific quality control challenges due to the age of the platform and the complexity of its backplane bus communication architecture. DriveKNMS applies the following inspection protocol to all K Series units prior to dispatch:

• Visual Inspection: Examination of PCB surface for corrosion, capacitor bulge, burn marks, and connector pin deformation. K Series edge connectors are inspected under magnification for oxidation and mechanical wear.
• Power Supply Verification: K62P and all K Series power supply modules are bench-tested under rated load conditions. Output voltage stability and ripple are measured against Mitsubishi Electric factory specifications.
• Backplane Bus Integrity: CPU and I/O modules are tested in a reference K Series rack to verify correct bus communication, module recognition, and error-free initialization.
• I/O Point Testing: All digital input and output points are individually cycled. Analog modules are calibrated against reference signals at 0%, 50%, and 100% of rated input/output range.
• Communication Module Validation: K6ADP and K6RS4 modules are tested for correct frame transmission and reception using protocol analyzers configured for MELSEC-NET/MINI-S3 and RS-485 respectively.
• Documentation: Each unit ships with an inspection record noting test date, technician ID, and pass/fail results per test category.