Safety interlock switch

Sep 02, 2023

By Leslie Langnau | June 13, 2019

The HS1T interlock switch with solenoid delivers 5,000 N of locking force. Many features are included to maximize protection in machine and equipment guarding applications.

The amount of locking force delivered in a small size is due to a metal head integrating the locking and mounting functions, an improvement over older designs where the head could break away from the mounting body. To maximize installation options, the remaining actuator portion can be independently rotated from the high-strength head using only one screw. With a slim form factor and many mounting options, the HS1T can be installed virtually anywhere, providing greater flexibility for designers.

Simpler wiring and safer operationWhile much of the HS1T's strength is provided by the metal head, the cam design also plays an important role. IDEC has included three independent rotary cams, instead of a single cam commonly used. Two cams control the locking mechanism and one drives the door monitor contact. This arrangement provides redundancy, additional strength and ensures the monitoring function continues to work even if a locking cam is damaged.

The HS1T meets the requirements of ISO 14119:203 for Lock Monitoring and are marked as such. This means both the status of the position and the locking function of a protective door can be monitored through the lock monitoring contact. The net result is that fewer on-board contacts are needed to achieve redundant safety circuits and additional monitoring circuits, reducing the amount of wiring on the device. For additional integrity, the device structure is designed so the lock monitoring contact can never indicate closed if the door is not positively closed, thereby preventing the associated machine from being turned on with risks exposed.

Installers will appreciate the HS1T's multiple available cable entry ports, with faster and more reliable wiring connections made possible by spring clamp terminals. These connections resis vibrations, prevent wires from loosening, and never need tightening. Designers can choose from spring lock or solenoid lock styles, with several options for contact configurations. These flexible installation options are complemented by an IP67 and Type 4X indoor use only rating.

An energy-efficient solenoid consumes only 200 mA while actuated, reducing electricity costs and allowing controls to activate the device directly without a relay. This is 25% less power compared to other models and among the lowest rating in industry.

Added featuresStructurally, the HS1T interlock switch can't be turned on unless the door lock is positively closed. As an additional protection against improper operation, designers can take advantage of the HS1T's compact size and mounting options to install it in normally unreachable, covered or hidden locations to minimize defeat possibilities.

Mechanical durability has been improved to two million operations. An optional manual rear-side unlock button allows personnel to release the device if they are inside a guarded area and need to exit. A rear unlock mechanical indicator, a first in the industry, allows the lock status to be identified from the front and the back.

IDEChttp://us.idec.com/HS1T