Mc and SC Models Manual Clean (Mc) units must be periodically turned off in order to discharged iron accumulated on the face of the magnet. They are suitable for applications where only where only occasional tramp iron is expected. These magnets are usually suspended from a travelling troly so that they can be swung clar of the conveyor before the iron is released. Self-Clean (SC) Suspended Electromegnats provide continous. Automatic removal of tramp iron and feature a heavy-duty belt. Channel frame for supporting the pulleys. Adjustable belt take-up and drive . They are recommended where a large amount of tramp iron is expected or where there may be limited access to the magnet for cleaning purposes.