Questions regarding the wiring of safety barriers
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New user asking about instruments: Regarding the wiring method for safety barriers, for example, radar level gauges that require 24V power supply and output a 4-20MA current, is it sufficient to simply connect the signal wire to the safety barrier? Is the power for radar level measurement supplied directly to the instruments on site via a circuit breaker?
For two-wire instruments, power is supplied directly by the card, so no circuit breaker is needed
I’m referring to four-wire meters; when such meters require an independent power supply, is that power supplied by a meter power supply box? Or should 24V be outputted to the instrument via the safety barrier for power supply?
It seems that circuit breakers are generally connected to high-voltage electricity. The radar level gauge is equipped with its own 24V power supply, which usually passes through a fuse.
Four-wire instruments have a separate power supply set that is provided to the instrument by the power supply cabinet, while another signal path passes through a safety barrier
I also don’t understand whether a low-current device is called a circuit breaker or a fuse. So does that mean the radar level gauge is powered directly by a power source? Isn’t that still the same as introducing dangerous electrical signals into the area? Is intrinsically safe still meaningful?
Reply to 6# commander263: The power supply section should be flameproof. You can refer to this post: http://bbs.hcbbs.com/viewthread.php?tid=775484&page=1
Thank you, moderator**~~~~~~~~~~
Our radar systems use 220V power, with circuit breakers and fuses; we haven’t encountered a 24V version yet. However, the power supply unit of the instrument itself should be explosion-proof, and it’s likely that a fuse or similar device will also need to be installed in the control room.
For E+H’s four-wire radar level gauge, the power supply is provided separately by a circuit breaker; the current may be supplied with 24V by a safety barrier
The last edit to this post was made by yi*ao20002005 on 2020-12-1 at 13:30. The power supply is connected directly to the instrument because the wiring for the power supply has been certified as explosion-proof