ZHUCO HZ12-40/08 OFFON Two-Position Two-Section Machine Tool/Lathe Electrical Cabinet Interlocking Power Cut-Off Changeover Switch

The HZ12-40/08 is a safety-type two-position (OFF-ON) power disconnect switch with a rated current of 40A. The product comes standard with an incoming line protective cover, and the emergency stop model uses a yellow panel and red knob for identification. It is specifically designed for equipment safety regulations. The cabinet door can only be opened when the switch is in the "OFF" position, forcibly achieving "power off upon door opening." Both the "OFF" and "ON" positions support padlock locking, providing a complete access control solution for equipment maintenance and operational status management.

1. Main Technical Parameters and Characteristics

Electrical Parameters: Conventional Free Air Heating Current (Ith): 40A (clearly indicated by "40" in the model number).

Contact Configuration and Function:

Position "1" (ON): All four main contacts 1-2, 3-4, 5-6, and 7-8 are closed.

Position "0" (OFF): All contacts are completely open, providing electrical isolation.

Core Safety Features:
Forced Door Interlock Mechanism: Linked to the cabinet door via mechanical linkage and cam mechanism. Before opening the door, the switch must be turned to the "OFF" position to unlock it; when the door is opened, the switch is mechanically prevented from turning to the "ON" position.

Dual-position padlock function: Padlock holes are available in both the "OFF" and "ON" positions (locks must be purchased separately). The "OFF" position is used for safety maintenance; the "ON" position is used to prevent unauthorized shutdowns and ensure production continuity.

Inlet cable protection cover: A protective cover is included as standard to prevent accidental contact with live terminals.

Wiring and structure:

Wiring capability: M4 wiring screws, suitable for larger cross-sectional area wires: 4.0 – 10 mm² (suitable for 40A current), tightening torque 2.0 N·m.

Structure and materials: Flame-retardant and high-temperature resistant shell; internal thickened copper conductors and silver alloy contacts ensure reliability and long lifespan under high current.

Operating Environment Conditions:

Temperature: -25°C to +40°C (24h average ≤ +35°C)

Altitude: ≤ 2000 m

Humidity: ≤ 50% at +40°C; up to 90% is permissible at lower temperatures (e.g., +25°C).

2. Application Scenarios

Core Application: Safety isolation of main power supply for high-risk industrial equipment

Large Machine Tools and Heavy Machinery: Used in CNC machining centers, power distribution cabinets, large stamping machines, injection molding machines, and electrical control cabinets for metallurgical equipment. The door interlock function mandates that maintenance personnel must disconnect the power before opening the cabinet door for maintenance, which is essential for compliance.

Automated Production Lines and Robotic Units: Serves as the main power switch for the entire workstation or equipment within a safety fence, ensuring the system is in a completely de-energized state when entering the fence for maintenance.