The external environment inspection of PLC mainly includes the following aspects:
1) Ambient temperature: The working temperature of the PLC should be kept between 0-55. If the ambient temperature is too high or too low, it may affect the performance and normal operation of the PLC. Therefore, it is necessary to check whether the temperature of the environment in which the PLC is located is suitable, and if the temperature is too high or too low, corresponding heat dissipation or heating measures need to be carried out.
2) Ambient humidity: The working humidity of the PLC should be kept between 35%-85%RH. If the ambient humidity is too high or too low, it may affect the performance and stability of the PLC. Therefore, it is necessary to check whether the humidity of the environment where the PLC is located is suitable, and if the humidity is too high or too low, corresponding dehumidification or humidification measures need to be carried out.
3) Air quality: There should not be too much dust, corrosive gas, flammable and explosive gas, etc. in the environment where the PLC is located, which may cause damage to the circuits and components of the PLC. Therefore, it is necessary to check the air quality of the environment where the PLC is located, and if these problems exist, corresponding ventilation, filtration and other measures need to be carried out.
4) Vibration and shock: PLC should avoid strong vibration and shock, which may cause damage to the circuits and components of PLC. Therefore, it is necessary to check whether the PLC is affected by vibration and shock, and if these problems exist, corresponding shock absorption or shock protection measures need to be carried out.
5) Grounding and lightning protection: The grounding and lightning protection measures of PLC are an important guarantee to ensure the safe operation of PLC. Therefore, it is necessary to check whether the grounding and lightning protection measures of the PLC are reliable, and if these problems exist, corresponding grounding or lightning protection treatment needs to be carried out.