Question 20Electricity & Electronics - 1st Asst/Chief

The correct answer is D) maintaining type push button with a mechanical interlock. The symbol shown in figure "6" of the illustration EL-0026 represents a maintaining type push button with a mechanical interlock. This means that the push button will remain in the actuated position until it is manually reset, and it is mechanically interlocked with another device or mechanism. The other options are incorrect because: A) A limit switch with normally open contacts would have a different symbol. B) A normally closed contact held open mechanically by an interlock would also have a different symbol. C) A maintaining type push button with an electrical interlock, rather than a mechanical one, would have a different representation.