Issues related to combustible gas controllers
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Dear experts, may I ask if there are any requirements regarding the distance between combustible gas controllers and combustible gas detectors? There is currently a combustible gas controller located in the central control room, about 1 km away from the field detectors. Is this acceptable? If I use a computer cable to connect the signals, do I need to choose a cable with a cross-sectional area of 2.5 mm2?
It doesn’t seem to have any requirements, but it’s so far away – will the information be okay?
Is it out of fear of signal interference? Afraid it won’t be accurate
It mainly comes down to the cables; cable resistance needs to be taken into account.
Yes, 1000 meters with a cross-sectional area of 2.5 is sufficient.
There are 2 solutions: 1. Use a fieldbus-based combustible and toxic gas controller, with the probes connected via a four-wire system; this setup can support distances of over 1 km. 2. The combustible and toxic gas controller is located in the on-site cabinet room of the device; signals are transmitted to the control room via fiber optics, where an upper-level computer is installed.
A wire diameter of 1.5 should be fine; it’s better to use 2.5 if possible. For 4-20mA signals, a shielded control cable will suffice
There are no specific requirements; as long as the signal transmission is fine, that’s enough
1.5 is sufficient; most combustible and toxic substances operate at 24V. The main consideration is voltage drop, and using too thick cables results in high costs
4~20ma, there is no need to worry about voltage drop for the signal.