What type of contacts may be added to a contactor when a momentary pushbutton switch is used?

When a momentary pushbutton switch is used in conjunction with a contactor, the appropriate type of contact that can be added is normally open. This is because a momentary pushbutton is designed to complete the circuit only when it is actively pressed.

Normally open contacts are designed to remain open until they are energized, meaning they will close when the pushbutton is pressed. This functionality is ideal for controlling a contactor, as it allows for a temporary connection. When the pushbutton is released, the circuit opens again, de-energizing the contactor.

Using normally closed contacts in this scenario would not be effective. Normally closed contacts are continuously connected until they are activated to open, which would not complement the momentary action of the pushbutton switch. This means that the device would remain active even when the pushbutton is no longer pressed, which is not the desired outcome in most control applications. Thus, normally open contacts are the correct choice for this setup.