Smartscan India Pvt. Ltd.

Trapped Key Interlocks for Access Control with Secondary Release Key (Stainless Steel)

Access control trapped key interlocks with a secondary release key ensures that a guard door is locked closed under normal operating conditions. Once the first key is inserted, a second key can be released (also known as a personnel key). The operator then takes the personnel key into the hazardous area to minimize the possibility of inadvertent start-up occurring. The first key remains trapped until the second key is returned.

Access control on a trapped key interlocking system refers to the method for controlling access to hazardous areas of machines and equipment. It involves granting users the ability to gain access, either in full- or part-body by following a sequential key process.

Trapped Key Interlocks are widely used in various industrial settings to safeguard workers and prevent accidents. It is a highly effective in ensuring safety protocols are strictly adhered to and that access to hazardous areas is only granted to authorized personnel.

Access control trapped key interlocks in 316 grade stainless steel are suitable for pressure washing with detergent at high temperatures. Each product is tested to IP69K, meeting the rigorous demands associated with food, beverage and pharmaceutical manufacturing.

Trapped Key Interlocks

Trapped Key Interlocking uses a proven mechanical method to control the safe sequence of operations for machinery and equipment, ensuring dangerous areas remain inaccessible until it’s safe to enter. A Trapped Key System works through the controlled release and transfer of coded keys, which become trapped or released in a specific order. This enforces strict safety procedures without the need for electrical wiring, offering a highly reliable solution where electronic systems may fall short.

Trapped Key Power Isolation Switches (Die-Cast)

Trapped key power isolation switches ISP and ISB can be used for electrical isolation of hazardous energy. They are ideal for use in harsh environments for isolation of power to machinery or switching currents up to 63A.

Each trapped key power isolation unit has up to 4-pole switching contacts when the key is inserted and in the ON position. Turning the key changes the switching contacts to the OFF position, stopping the hazardous electrical energy.

Upon isolation, the key can be freed and transferred to the next stage of the trapped key interlocking system. Only when the key is returned, can the electrical energy be restored and the hazardous process be reinstated.

Light Curtain Prohibitive Blocking Device with Personnel Key to Prevent Unexpected Start-Ups (LCB)Light Curtain Blocking Device (LCB) is a highly versatile trapped key safety solution designed for both new installations and retrofit applications. It is an optoelectronic device that provides a robust blocking function to enhance safety when used with light curtain systems, which improve machine or production line accessibility by reducing the need for mechanical guarding. The LCB ensures a secure lock-off, preventing the reactivation of the light curtain barrier when installed correctly.

Key exchange systems for trapped key interlocking are used when a single point of isolation requires entry to multiple access points at the same time.

Once the source of hazardous energy has been isolated, the isolation key is transferred to the key exchange system. Inserting and turning the key releases the access keys – this causes the isolation key to become trapped until all access keys are returned.

Our vertical key exchange systems are robust, compact and suitable for installation on guard frames.

More complex systems can be achieved using an MX panel, which can accept up to 5 keys IN and 15 Keys OUT. This is especially advantageous when there are multiple points of isolation or the use of “authority keys” is required to access the machinery.