means LACK OF RADIATION / RADIATION.
This proves that the industrial chiller is working on the principle of radiation or radiation, and when this light is on, there is a lack of radiation or radiation. I have not seen that thing, I am not sure what it is,
Another refgas, gas is a gas, ref is related to the refrigerator, you look at the manual, look at the chiller in which gas is related to the refrigerator, such as Freon, or what.
There is also the possibility that refgas refers to cold air.
When this light is on, there is a lack of refgas in the machine, or the temperature is too high (due to lack of refgas)
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