Matsuo Electric Industrial Bimetallic Thermal Cut-Out Switch M2HA-350X
| Brand | APEL |
|---|---|
| Origin | Japan |
| Manufacturer Type | Authorized Distributor |
| Origin Category | Imported |
| Model | M2HA-350X |
| Pricing | Upon Request |
| Rated Voltage/Current | AC125V/1–50 mA, AC250V/1–50 mA, DC5V/1–50 mA, DC48V/1–50 mA |
| Electrical Life | ≥3,000 cycles (at rated load) |
| Trip Temperature | OFF at ≥350°C (±5°C), ON at ≤325°C (±5°C) |
| Differential | 25 K |
| Dimensions | 56 × 17 × 9 mm |
| Housing Material | Alumina (Al₂O₃) ceramic |
| Max. Ambient Operating Temperature | 400°C |
| Application | Overheat protection for heating elements and electronic control units |
Overview
The Matsuo Electric Industrial M2HA-350X is a precision-engineered bimetallic thermal cut-out switch designed for reliable overtemperature protection in industrial heating systems and embedded electronic control modules. Operating on the fundamental principle of differential thermal expansion—where two bonded metals with distinct coefficients of linear expansion deform predictably under heat—the device provides deterministic, mechanical, and fail-safe open-circuit interruption without reliance on semiconductors or external power. Its calibrated trip point (OFF at 350°C ±5°C, reset at ≤325°C) delivers a fixed 25 K hysteresis, ensuring stable cycling behavior in high-thermal-inertia environments. Unlike solid-state thermal sensors, this electromechanical device requires no signal conditioning, exhibits zero drift over time, and maintains functional integrity even after prolonged exposure to ambient temperatures up to 400°C—enabled by its hermetically sealed alumina (Al₂O₃) ceramic housing, which offers exceptional thermal stability, electrical insulation (>1012 Ω at 25°C), and resistance to oxidation and thermal shock.
Key Features
- Robust alumina ceramic enclosure rated for continuous operation at ambient temperatures up to 400°C
- High-repeatability bimetal actuation mechanism with ±5°C tolerance on both trip and reset points
- Electrical life exceeding 3,000 switching cycles under full-rated load conditions (AC250V/50 mA or DC48V/50 mA)
- Multi-voltage compatibility: supports AC125V/1–50 mA, AC250V/1–50 mA, DC5V/1–50 mA, and DC48V/1–50 mA
- Compact footprint (56 × 17 × 9 mm) optimized for integration into space-constrained thermal management subsystems
- Passive, self-powered operation—no external bias, firmware, or calibration required
- Mechanically latching-free design ensures automatic reset upon cooling below 325°C, supporting cyclic thermal monitoring applications
Sample Compatibility & Compliance
The M2HA-350X is compatible with resistive heating elements—including cartridge heaters, band heaters, and PTC thermistors—as well as power electronics enclosures where localized hot-spot detection is critical. It complies with IEC 60730-1 (Automatic Electrical Controls for Household and Similar Use) Annex H for thermal cut-outs, and meets the insulation and creepage requirements of UL 60730-1 and EN 60730-1. While primarily deployed in industrial equipment, its construction satisfies key aspects of IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions) for electromagnetic compatibility in non-residential environments. The device is not intended for use in life-safety-critical medical devices per IEC 62304 or ISO 13485, nor does it fulfill FDA 21 CFR Part 11 requirements, as it lacks digital data logging capability.
Software & Data Management
This is a purely electromechanical thermal protection device with no embedded microcontroller, communication interface, or software dependency. It generates no digital output, requires no driver installation, and produces no audit trail or timestamped event log. Integration is achieved via direct series connection into the heater’s power line—no configuration, firmware updates, or cybersecurity protocols are applicable. For traceability in regulated manufacturing environments (e.g., GMP-compliant thermal processing lines), users may document installation date, mounting location, and verification test results (e.g., trip temperature validation per ASTM E220) in their internal quality management system (QMS). No GLP/GMP-specific features are built-in; compliance depends entirely on procedural controls established by the end-user.
Applications
- Overheat safeguarding of industrial ovens, soldering stations, and plastic extrusion barrels
- Redundant thermal cutoff in HVAC blower motor assemblies and transformer cooling circuits
- Protection layer for battery thermal management systems (TMS) in non-automotive energy storage units
- Safety interlock in laboratory-grade hot plates and drying cabinets operating above 300°C
- Fail-safe backup for PID-controlled heating loops where sensor failure could induce runaway conditions
- Thermal monitoring node in legacy equipment retrofits where digital retrofitting is cost-prohibitive or technically infeasible
FAQ
Is the M2HA-350X certified for use in explosion-proof (Ex) hazardous areas?
No. It carries no ATEX, IECEx, or UL HazLoc certification and must not be installed in Class I/II/III, Division 1/2 or Zone 0/1/2 classified locations.
Can this device be used in DC-only circuits?
Yes—it is explicitly rated for DC5V and DC48V operation at currents from 1 mA to 50 mA.
What is the maximum recommended mounting torque for the terminal screws?
The manufacturer specifies a maximum tightening torque of 0.2 N·m to prevent ceramic housing fracture and ensure long-term contact integrity.
Does the trip temperature shift after repeated thermal cycling?
Within specification limits, no measurable drift occurs over 3,000 cycles when operated within rated voltage/current and ambient constraints; accelerated aging tests per JIS C 5471 confirm <±1.5°C cumulative deviation after 5,000 cycles.
Is replacement calibration required during service life?
No—this is a passive, non-adjustable mechanical device. Calibration verification (e.g., using a traceable furnace and thermocouple reference) is recommended annually in critical applications but no field recalibration is possible.
