Here is the professional English translation of the emergency stop switch document, preserving the original structure, formatting (headings, tables, bold text), and technical accuracy:

I. Core Mission of the Emergency Stop Switch
The Emergency Stop Device (ESD, compliant with IEC 60947-5-5) is a mandatory safety component in industrial control systems. Its core objective: To quickest cut off hazardous motion/energy sources in an emergency, preventing personnel injury, equipment damage, or environmental hazards. Adhering to the "fail-safe" principle (fault leads to a safe state), it is applied in high-risk fields such as machinery manufacturing, automated production lines, robots, and power systems.

II. Core Working Principle

• Positive Opening Operation
  • The actuator (mushroom head/pull-cord/foot pedal) directly drives the contacts via mechanical linkage, no spring dependency.
  • Even if the spring fails or jams, pressing the actuator forces the contacts open.
• Normally Closed Contacts (NC)
  • Contacts are closed in the normal state, connected in series within the equipment's main control circuit.
  • Upon activation, contacts open → control circuit loses power → equipment stops (Stop Category 0/1, compliant with IEC 60204-1).
• Latching and Reset
  • Mechanically latched after activation, requiring manual rotation/pull for reset, preventing unintended restart.
• Redundancy and Monitoring (High Safety Level)
  • Two sets of NC contacts connect to a safety relay, monitoring contact status, synchronization, and circuit integrity.
• Fail-Safe Design
  • Spring failure: Contacts can still be forced open.
  • Contact welding: Redundant contacts ensure shutdown.
  • Mechanism jamming: Pressing the actuator can overcome jamming.

III. Key Performance Parameters
Electrical Performance

Mechanical Performance

Environmental Parameters

• Operating Temperature: -25℃~+70℃ (Industrial Grade)
• Humidity: ≤95% RH (+25℃)
• Pollution Degree: PD 3 (Industrial Environment)

IV. Core Materials and Processes

• Contact Material: Silver alloy (AgSnO₂ based), arc-resistant, anti-welding.
• Housing Material:
  • Engineering Plastics: PA (Nylon), PC (Polycarbonate), flame-retardant V-0 grade.
  • Metal: Stainless Steel (SS304/316), for corrosive environments.
• Actuator: Red thermoset plastic (conforms to RAL 3000), UV-resistant.
• Processes:
  • Precision injection molding/stamping.
  • Laser welding of contacts.
  • 100% testing of operating force, contact status, and dielectric strength (≥2Ui + 1000V).

V. Application Fields

VI. Installation Specifications (ISO 13850 / IEC 60204-1)

• Location Requirements:
  • Accessibility: Quickly reachable by operators and personnel in hazardous areas.
  • Visibility: Red mushroom head + yellow background, unobstructed.
  • Coverage: Large equipment requires multiple points (per operating station/hazard entrance).
• Installation Methods:
  • Panel Mounting: M22/M30 threaded fixing, sealing ring ensures IP rating.
  • Pull-Cord Switch: Cord height 0.8m~1.7m, with cord break detection.
  • Foot Pedal Switch: Securely fixed to floor, non-slip pedal.
• Safety Circuit Design:
  • Contacts connect to safety relay/PLC (not ordinary control circuits).
  • Redundant contacts connected in series for dual-channel monitoring.
  • Distinct wire color (e.g., orange), isolated from power cables.

VII. Selection Guide

• Safety Level: PLd/e or SIL 2/3 requires 2 NC groups + safety relay.
• Operation Method:
  • Mushroom head (General purpose), Pull-cord (Long boundaries), Foot pedal (Hands-busy scenarios).
• Environment Adaptation:
  • Food factory: IP69K + Stainless steel housing.
  • High-temperature workshop: Materials resistant to >70℃.
• Certification: CE, UL/cUL, CCC (Mandatory for target markets).

VIII. Maintenance & Testing

• Periodic Testing:
  • Trigger E-stop at least annually to verify complete equipment stop (record results).
• Routine Inspection:
  • Visual damage, contamination, loose fixing.
  • Operation smoothness (no jamming/abnormal noise).
• Replacement Principle: Replace immediately upon damage, malfunction, or reaching lifespan limit.
• Safety Culture:
  • Train operators for "emergency use only", prohibit bypassing E-stop function.
  • Keep access paths clear.

IX. Development Trends

• Intelligence: Integrated diagnostics (contact status monitoring), LED status indication.
• Networking: Signal transmission via safety buses (e.g., PROFIsafe).
• Ergonomics: Optimized actuator texture/force curve, easy-to-clean design.

X. Conclusion
The Emergency Stop Switch is the "final safeguard" of industrial safety. Its reliability depends on:

1. Positive opening + redundant contact design;
2. Selection compliant with standards (electrical/mechanical/IP rating);
3. Correct installation (location/circuit monitoring);
4. A culture of regular testing and maintenance.