First points of failure (failure most places) in the relays, contactors
Daily maintenance of PLC control system of production line in the largest electrical spare parts consumption for various types of relays or the air switch. Main reasons in addition to the product itself, is environment is harsher, contactor arcing contacts or oxidation, then heat deformation cannot be used. Reducing this type of problem should be as high performance relays, improving the components using the environment, reduce the frequency of change, in order to reduce their impact on the system.
Type II multiple points of failure in the valve or gate on this kind of device
Because this type of device the key executive positions, relative displacement is larger, or through electric conversion, and several steps to complete valve or gate location transformation, push-pull or electric actuators or gate position of valve conversion, mechanical, electrical, hydraulic, and other aspects in place will produce errors or failures. Long-term use, lack of maintenance, mechanical or electrical failure is the main cause for the failures, so while the system is running to strengthen the inspection of such equipment, identify problems and deal with. I plant to set up a strict system of inspection of such equipment, always check whether the valve distortion, the executive body is flexible and available, the controller is valid, well to ensure the effectiveness of the control system as a whole.