Principles for selecting fuses in the instrument cabinet room
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Principles for selecting fuses in the instrument cabinet room: For example, which brands to use, what size of fuse is appropriate for a single circuit, what size fuse is suitable for an 8-channel relay, what size fuse is needed for an 8-channel safety barrier, and what size fuse should be used for the 24V power supply that powers the cards.
The operating current of the instrument circuits is relatively low, with each circuit having a current of only a few dozen mA. Moreover, there are no significant high-current surges in the circuit devices (sensors, transmitters, or actuator coils); therefore, issues such as overload, overvoltage, or undervoltage generally do not occur. The main purpose of circuit protection is to prevent short circuits, so in my practical experience, values between 0.5 and 1 mA are sufficient. For the driving characteristics of individual solenoids in the output circuit, 2mA may be used. Just my opinion, for reference.
It can be calculated simply: generally, an electromagnetic valve consumes 3.5 W of power, operates on 24 VDC, with a current of 0.14 A. A current of 0.5A is sufficient for a single circuit, as the short-circuit current is very high. It is also necessary to consider that the availability should not be compromised by frequent burnouts. As for using milliampere levels, that definitely won’t work.
I haven’t paid much attention to brands; generally, products made by reputable manufacturers are fine. For valves and relays, 1A is sufficient. Electrical relays used in pumps require 2A, while those used in compressors can work with either 2A or 5A. A safety barrier isn’t necessary. For 24V devices, 2A is also sufficient
I haven’t paid much attention to brands; generally, products made by reputable manufacturers are fine. For valves and relays, 1A is sufficient. Electrical relays used in pumps require 2A, while those used in compressors can work with either 2A or 5A. A safety barrier isn’t necessary. For 24V devices, 2A is also sufficient