1, the geographical position and climate factors
Mainly refers to the altitude, temperature, humidity, and electromagnetic interference and other factors. Considering the general applicability of the control system, both must be long
Themonths and years of reliable operation, the key parts of the device must be used with high insulation, strong anti electrical performance of whole sealing type (metal sealing cover or plastic type, metal cover sealing product is superior to plastic products) the intermediate relay. Because only the whole sealed relay has excellent long-term tolerance to severe environmental performance, good electrical contact stability, reliability and load capacity (switching from external climate environment).
2, mechanical action elements
Mainly refers to the vibration, impact, impact and other factors of stress. The control system mainly taking into account the anti earthquake should force and resistance to mechanical should force ability, should use the balanced armature mechanism of miniature intermediate relay.
3, excitation coil input parameters
Mainly refers to a incentive, lack of motivation, low voltage stimulation and high voltage (220 V) output isolation, influence of temperature change, long distance wired excitation, electromagnetic interference incentive parameter elements, these are to ensure the reliable operation of the power system automation device must seriously consider the factors. According to the incentive amount of the small intermediate relay is the necessary condition to ensure its reliability and stability.
4, contact output (switching circuit) parameter elements
Mainly refers to the contact load properties, such as lamp load, the capacitive load, motor load, the load inductor, a contactor (relay) coil, resistive load; contact load value (open circuit voltage value, closed-circuit current value), such as low level load, dry circuit load, the load current is small, high current load.
Any automation equipment must be identified and the size of load characteristics, load value of the actual needs, choose appropriate relay products is particularly important. The failure of the relay or reliable, mainly refers to the contacts can accomplish the function of switching circuit. If the actual load is not consistent with the provisions of the selected relay switch load switch, the reliability will be impossible.