Do four-wire instrument power lines and signal lines require two glands each?
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Do the 24V DC power supply and the 4-20mA signal cable need to be separated from the Grant? Is a four-core cable sufficient with just one gland?
Field instruments powered by DC24V are generally two-wire systems. The power supply for four-wire instruments is generally 220VAC, and the power lines and signal lines should be separated.
The four-wire type has 24V DC
In a four-wire system, they are generally separated; the electrical interfaces for power and signals are distinct from each other.
They are all 24V, so there’s no need to separate them; the power consumption of the smart transmitters on site is very low
Look, with a 220V supply separated, 24V can be used directly with 4 wires
Although it’s a 24V power supply, I still think it’s better to have the power supply and the signal separated. Because it will be more convenient for future modifications, cable inspections, and maintenance. Moreover, it is also difficult to run four-wire cables through tubes. Besides, in case the instrument is later switched to 220V power supply, there’s no need to change the wiring.
There is no need to separate the 24VDC power supply; the 220V one needs to be separated
Since 24VDC is a low voltage, a four-core cable can be used. But it is better to use 2 RVVP2*1.5 cables with 2 glands.
24V has no interference, so it’s fine
It is not an intelligent transmitter; the power supply circuit allows a current of up to 100mA