Regular maintenance equipment activity Activity description Recommended interval Visual check of Devic Check the status of equipment, wires, safe connections, corrosion of metal parts monthly Cleaning of equipment Remove dust and impurities from the surface of the equipment and check and replace fan filters biannual Check the tightness of the connector Compactness of all connections for connection terminals and input and output cables for all machines Once a year Modify El.box connection No modification shall be made to the connection or modification of the electronic box without the written consent of the manufacturer. The manufacturer shall evaluate the proposed modification of a project document on the following basis. Modifications to equipment or electronic boxes can only be made by qualified personnel