Solenoids

Component Related Documentation

A solenoid is an electrical device which converts electrical power into mechanical movement. A solenoid consists of a coil of wire surrounding an armature, which is a movable metallic core and a spring. When an electric current is switched on to flow through the coil, an electromagnetic field is produced which, depending on the design of the solenoid, either pulls the armature into the field or pushes the armature out of the field. Either way, electrical energy is converted into linear mechanical energy. When current to the coil is shut off, the spring returns the armature to its de-energized position. The force developed by a solenoid is determined by the number of coil turns and the amount of current applied to the coil. In fluid power applications, solenoids are most commonly used to actuate valve spools or poppets. However, solenoids can control many other devices which can be operated by short-stroke mechanical motion.

Safety Related Notes

Before working on this machine, perform lockout-tagout procedures per the rules of your plant. Determine the sources of energy on this machine – electrical, pneumatic and hydraulic – and release or vent sources of stored energy – electrical capacitors, air receivers, and hydraulic accumulators. Shut off sources of power – electrical, pneumatic and hydraulic. Safely block mechanical sources of energy such as loaded springs and loaded machine members, or safely position the machine members so they are unloaded and springs are not under tension. Beware of hot hydraulic fluid and hot surfaces which can cause burns. Never “crack a hydraulic or pneumatic fitting” to check for the presence of stored energy. Hydraulic fluid injection injuries, as well as injection injuries from many other fluids, are extremely serious and must be treated immediately by medical personnel familiar with this type of injury. Loss of body parts or death may result from improperly treated fluid injection injuries! Never use your hands to feel for a hydraulic leak! Never use compressed air to blow dust off yourself or someone else – there is risk of an air injection injury. Review the schematics and think before proceeding to work on the machine to ensure you have made the machine safe to work on.