How should refrigerant be recovered from a chiller?
A) Always begin the refrigerant recovery using vapor recovery methods
B) The chiller should be operated to build pressures prior to starting recovery
C) Always begin the refrigerant recovery using liquid recovery methods
D) Refrigerant should be pushed out by pressurizing the chiller with 50 psig of nitrogen
Q. 2What can cause the supply voltage to a system to drop below the minimum voltage when the unit is operated?
A) The system may be low on refrigerant, causing a high amp draw as the compressor struggles to cool the structure.
B) A dirty air filter may be causing a high evaporator fan motor amp draw.
C) Power wire is too small or poor connections at either end of the power wire
D) This is normal. The minimum voltage only refers to the voltage with the unit off.
Q. 3How is the water flow in a hydronic heating system checked?
A) By measuring the pressure drop across the water pump and comparing it to a pumping performance chart
B) By measuring the amp draw of the pump motor an applying the formula gp = amps x 1.73
C) By measuring the pump motor RPM using a digital tachometer
D) By measuring the impeller RPM using a stroboscope
Q. 4How are water pumps in hydronic heating systems checked?
A) By measuring the pump motor RPM using a digital tachometer
B) By measuring the water flow in the system
C) By measuring the impeller RPM using a stroboscope
D) by measuring the temperature of the pump motor
Q. 5Oil is removed from the refrigerant vapor by a
A) mist eliminator in the heater. B) valve in the cooler.
C) filter in the condenser. D) coil in the vaporizer.
Q. 6How is a temperature-pressure relief valve on a hot-water boiler tested?
A) Pressurize the boiler with nitrogen until the pressure relief valve opens.
B) Pressure relief valves are optional, so testing is not required.
C) Jump the high limit and operate the burners until the pressure relief valve opens.
D) Pull lever and look for water at outlet of discharge pipe.
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