You are checking the supply chilled water temperature thermistor probe on a high- pressure hermetic centrifugal chiller. Using the illustrated chart, what statement is true if the supply water temperature is verified 45 ° F with a digital thermometer? GS-RA-48

Illustration GS-RA-48: the U.S. Coast Guard has not released this illustration.

Question

You are checking the supply chilled water temperature thermistor probe on a high- pressure hermetic centrifugal chiller. Using the illustrated chart, what statement is true if the supply water temperature is verified 45 ° F with a digital thermometer? GS-RA-48

Illustration GS-RA-48: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option C: When checked with control power on and the thermistor probe connected into the circuit, the thermistor probe voltage drop should be 3.805 volts.. In a chiller control circuit sensing 45 degrees Fahrenheit, the connected thermistor probe establishes a specific voltage drop of 3.805 volts across the sensing circuit. Isolating the probe changes the parallel resistance and alters the measured voltage drop.