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Basic definition of associated devices
Refers to the installation of energy limiting circuits and non energy limiting circuits, and structurally enables nonZhongnuo TestingElectrical equipment that cannot have adverse effects on energy limiting circuits.
The basic function of associated devices
Associated devices, as energy limiting devices, can effectively protect on-site equipment in hazardous areas, enabling the system to function properly under normal working conditions, while under fault conditionsZhongnuo TestingLimit the voltage and current that can reach hazardous areas.
Classification of associated devices
Common associated devices in practical applications include safety barriers, which are further divided into Zener type safety barriers and isolation type safety barriers. And then there's alsoIntrinsic safetyPower supply.
The associated device can be any of the following two:
（1）WithGB 3836 1-2010Another explosion-proof type specified can be used in electrical equipment in corresponding explosive gas environments;
（2）Not adoptedExplosion proof typeElectrical equipment that cannot be used in explosive gas environments for protection. For example, a recorder, which is not in an explosive gas environment but is connected to a thermocouple in an explosive gas environment, can only recordZhongnuo TestingThe input circuit of the recorder has energy limiting characteristics.
Simply put, associated equipment should be used in a safe place and then powered or communicated with intrinsic safety equipment in a hazardous area without affecting its intrinsic safety parameters. So the output circuit of the associated equipment must be an intrinsic safety circuit. If used in hazardous areas, the associated equipment must be protected with another explosion-proof type, such as an explosion-proof enclosure.
It is worth noting that there is no temperature group for associated devices, which is commonExplosion proof signsAs follows:
［Ex ia Ga]IIC
Intrinsic safety electrical parameters:UoIoPoCoLo;
When associated with other devices, the selection generally follows the following principles:
Ui ≥ Uo,Ii ≥ Io,Pi ≥ Po,Ci ≤ Co,Li ≤ Lo;
Safety barriers are mainly installed in safe places and contain devices with intrinsic safety circuits and non intrinsic safety circuits. The circuit passes through the limitZhongnuo TestingThe current and voltage limiting circuits limit the energy sent to the on-site intrinsic safety circuit, thereby preventing dangerous energy from non intrinsic safety circuits from cascading into the intrinsic safety circuit.
Application example: Explosion proof power supply device provides power to external intrinsic safety equipment; The collector collects intrinsic safety equipment signals from explosion-proof areas
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