FAQ02351 of Safety Limit Switches FAQ

SPST-NC + SPST-NO Contact (Snap Action) Example

The SPST-NC + SPST-NO contact snap action switches have the direct opening mechanism (forcibly opened contacts) defined under EN 60497-5-1. The NC contact side is the only side with a direct opening mechanism (forcibly opened contacts).

1. When contact welding occurs.

2. When contacts are being pulled apart.

Safety cam directly pushes up the movable contact blade.

3. When contacts are completely pulled apart.