RS PRO Energise to Hold Magnetic Locks. Designed for use with machine mechanisms or as door magnets, our high quality RS PRO range presents this small yet powerful magnetic lock. Able to remotely lock or un-lock with quick operation, these electro-permanent magnets are energised to hold and de-energised to release. Optimum performance when used with RS armature plates (available separately): please see stock no ; 739-3211 739-3211 etc. Energise to release version available on example ; 739-3220 739-3220 12 and 24 vdc versions have a 2 pole connector 12 and 24 vdc versions are IP20 rated 240 vac versions have a Din 43650 connector 240 vac versions are IP54 rated. How to install a door magnet?. Generally the electromagnet is attached to the door frame, whilst an armature plate is attached to the door itself. Occasionally brackets may be needed to ensure the magnet is in the correct position for contact with the plate. To achieve the optimal pull force of 100%, a contact area must be achieved using the recommended armature plates.