The Allen-Bradley 849-Z0D32 Pneumatic Timing Relay is an electro-pneumatic device that provides a configurable time delay before changing its operating status after being energized. More specifically, after the coil is energized, this type of timing relay will retain the electrical status of its contacts for a user-defined amount of time before changing from the normally open status to the closed status. The Allen-Bradley 849-Z0D32 Pneumatic Timing Relay is simple to adjust by turning a screw-type needle valve to regulate the speed of the air flowing inside the pneumatic mechanism. Its basic principle of operation is a normally-open electrical contact that is physically connected to bellows and which actuates the contact to close the circuit when the coil is energized. The bellows are also connected to a spring that will return them to their resting position when the coil is de-energized.

The Allen-Bradley 849-Z0D32 Pneumatic Timing Relay is a common industrial control component that is often used in applications in environments with a hazardous or explosive atmosphere, such as applications in the oil and natural gas industries, or applications with any type of flammable materials in suspension. The relay also has other advantages over electrical timers because it is immune to high humidity or variations in atmospheric pressure and environmental temperature. The Allen-Bradley 849-Z0D32 Pneumatic Timing Relay can be used in both outdoor applications and indoor applications, but like any industrial control equipment, placing it in a protected enclosure will extend its lifespan. It is important to guarantee a clean air supply for the device because excess moisture inside the relay may lead to faults.