Allen Bradley 808 Speed Sensing Switches

The Bulletin 808 speed-sensing switches are Allen Bradley switches or pilot devices that can control squirrel cage motors. These switches provide electrical signals at specific speeds, and they can provide plugging, anti-plugging, direction of rotation, and speed-sensing signals. Common applications for 808 speed-sensing switches include machine tool applications, conveyor sequencing applications, and fan or pump rotation applications. Switches that are used in plugging applications have normally open contacts, while switches that are used in anti-plugging applications have normally closed contacts. In plugging applications, 808 switches can be used with reversing starters to stop a motor quickly. In anti-plugging applications, 808 switches can be used to prevent system power from reversing suddenly. In direction-of-rotation and speed-sensing applications, switches with normally open or normally closed contacts can be used, depending on the requirements of the specific direction-of-rotation and speed-sensing applications. The precision bearings in the 808 speed-sensing switches are designed to have long operating lifespans and they are permanently lubricated. Additionally, these switches support double shaft seals that can be replaced when they wear out.

The Allen Bradley 808 speed-sensing switches support speed settings between 15 and 1000 RPM. They can handle motor shaft speeds of up to 2000 RPM. The 808 speed-sensing switches are available with different enclosures, including NEMA Type 7 and 9 enclosures and NEMA Type 1, 4, or 13 enclosures. These switches support different mounting brackets depending on their enclosure types. The 808 speed-sensing switches with NEMA Type 1, 4, or 13 enclosures can support 3 different types of mounting brackets that are all interchangeable. These interchangeable mounting brackets include base-type mounting brackets, 3-point flange mounting brackets, and 4-point flange mounting brackets. The 808 speed-sensing switches with NEMA Type 7 and 9 enclosures only support base-type mounting brackets. All 808 speed-sensing switches must be wired with wires that are suitable for temperatures of at least 90 degrees Celsius. The 808 speed-sensing switches can support optional lock-out solenoids for safety. These lock-out solenoids are solenoids with covers that can be mounted on top of the 808 switches.