Insulation issue in the wiring of infrared flame detectors
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After the signal from the infrared flame detector enters the cabinet room, use a multimeter to measure the resistance of the circuit relative to ground: with the black probe connected to ground and the red probe connected to the circuit, the resistance is 10 M ohms; when the red probe is connected to ground and the black probe is connected to the circuit, there is a conductive path. Can this indicate that it’s a wiring issue? Is there also a difference between forward and reverse when measuring resistance? It should be noted that the equipment is present on site along with junction boxes. The insulation records prior to power restoration are missing; can the above information be used to conclude that it is a quality issue with the wiring? Thank you all, experts.
It’s probably a wiring issue; try using a different cable, or try another multimeter.
Infrared flame detectors output switch signals. Even though their technical specifications indicate a output of 4–20mA, this is not actually the case in reality; the output cannot be continuous, as there are only two possible states for flame detection: either there is a flame or there isn’t. It’s not a matter of the flame being strong or weak. Since it’s a switch output, there must be a relay switch as well. I think this is probably related to the contacts of the relay! I can’t be sure yet; I’ll study our unit’s ultraviolet, infrared, and triple-infrared flame detectors more closely and share my findings with you once I have an answer.