What Is The Technical Requirement Of UL Certificate For Safety Interlock Switch?

Safety door switches must have sufficient mechanical strength to withstand various external forces in industrial environments. For example, the operation of machines at the production site will generate vibrations, and personnel may accidentally bump into the door lock safety switch during operation. These situations require the interlock switch to be able to operate stably without damage. When locked, it must withstand a static tensile force of ≥1300N to ensure that the locking safety switch does not fail under abnormal external forces (such as forklift collisions or personnel leaning on it).

When the safety interlock door switch is closed, the switch contacts must be in a state without mechanical pressure (non-pressurized) to avoid elastic failure caused by long-term compression of the spring. Because ordinary switches rely on spring reset, long-term compression can easily lead to elastic failure; the forced disconnection structure avoids long-term compression of the spring, prolongs its life and prevents the risk of "contact sticking". Ensure that the normally open (NO) and normally closed (NC) contacts of the switch are physically interlocked - when the NO contact is closed, the NC contact is forced to open, and vice versa, and the two cannot be closed at the same time (to prevent the risk of short circuit).

The protection level is an important indicator to measure whether the industrial safety door switch can resist the invasion of external harmful substances. Common protection level requirements are such as IP65, IP67, etc., which means that the door switch can effectively prevent dust, water, oil, etc. from invading its interior. In some industrial sites such as food processing and automobile manufacturing, equipment needs to be cleaned and disinfected frequently, and splashing of water and detergent is inevitable. If the protection level of the door switch is insufficient, moisture and impurities enter, which may cause problems such as short circuit and rust of mechanical parts, thereby affecting the normal operation of the door switch and posing safety hazards.

It is necessary to pass a mechanical cycle test of ≥1 million times (typical requirement for elevator door locks) to verify long-term reliability.

The conductive parts, such as the metal casing of the safe lock interlock, must have reliable grounding measures. Once a leakage fault occurs in the equipment, the grounding device can quickly conduct the leakage current to the earth, thereby reducing the risk of electric shock. The grounding resistance must comply with the relevant standards, and the grounding connection should be firm and reliable, and will not loosen due to factors such as vibration and movement of the equipment. In actual industrial production, poor grounding of electrical equipment is one of the common causes of safety accidents, so ensuring the reliability of the interlock switch grounding is crucial to overall industrial safety.

Multiple groups of contacts (2/4/6 groups) need to be physically isolated to prevent short circuits from causing safety function failure; explosion-proof scenarios need to suppress switch arcs (such as fully sealed arc extinguishing design).

The installation location must be "inaccessible or invisible" (such as hidden installation or protective cover); fasteners must rely on special tools for removal (such as hexagonal/star screws), and easy-to-remove cross/slotted screws are prohibited.

Enhanced testing of electrostatic discharge (±8kV), electrical fast pulse group (±2kV), and surge (±1kV).

reaching a certain protection level, such as IP65, IP67, etc., is suitable for dusty and humid environments, ensuring long-term stable operation in complex industrial environments. It is not only related to whether the interlock switch can resist the erosion of daily water, oil and other substances, but also ensures long-term stable operation in complex industrial environments. For example, in an electronic manufacturing workshop, the air may contain trace amounts of chemical vapors. If these substances invade the inside of the door interlock switch, they may corrode circuit boards and electronic components, affecting the normal function of the door switch. Door safety switches with high protection levels can effectively avoid such problems.

Moderate operating force and reasonable operating stroke design enable operators to easily and accurately complete locking and unlocking operations. During long-term operation, excessive operating force will cause operator fatigue, affect work efficiency, and may even lead to operating errors. Reasonable stroke design can ensure that operators have enough space and clear feedback during operation, improving the accuracy and convenience of operation.

Clear and unambiguous labels and instructions are the key to ensuring safe and convenient operation. For example, set obvious lock status indicators and unlock direction indicators on the safety interlock switch with guard door locking so that operators can intuitively understand the working status of the door switch and avoid misoperation. At the same time, labels and instructions should have good visibility and durability, and will not be difficult to identify due to wear, fading and other factors during the operation of the equipment, ensuring that operators can accurately obtain relevant information about the interlock safety switch at any time.

TUV certification requirements for industrial magnetic interlock safety switch cover mechanical performance, electrical safety, functional safety, environmental adaptability, ergonomics and ease of operation. These requirements are designed to ensure that industrial magnetic safety interlock switch can operate stably and reliably in various complex industrial environments, effectively protecting the safety of personnel and equipment. Enterprises should fully understand and strictly follow these requirements, optimize product design and production processes, improve the quality and safety of industrial mechanical safety interlock switches, and safeguard the safe operation of industrial production.