Have a 10 ton HVAC unit supporting a computer room on and military base in South Korea. Alarms are "Loss of air flow" and "Overtemperture" Sure overtemperature will ocur with no air flow.-- Filters are clean, blower drive belts and wheels are in good shape-- I think the problem is with the small pc board with the single sensor on it. "Senser Board-- Part number 0617222. Here is the problem-- this unit was made in Australia and the factory closed and went to China. Assuming this is the problem, Where can I get a new board?
Sounds like dirty air filters!
The alarm looks for differential across the return, which incorporates the filters and indoor fan suction.
Dirty filters would result in "Loss of Cooling" which would result giving over temperature alarm.
Dealing with Global Warming
i would not blame the board right away
you probably have a faulty sail switch
double check it for open/close/stuck circuit
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