HVAC competency Exams Questions And Verified Answers

If a natural gas piping system fails a pressure test, the technician must re-pressurize the system and check for leaks with? - Answer-soap bubbles a pressure relief valve is installed to? - Answer-avoid exceeding the system limits In a refrigeration system, what must be installed at 10' intervals on the suction line if the compressor is above the evaporator? - Answer-Trap What occurs if a 3 amp load is connected to the secondary winding of a 24 volt, 40 V.A. transformer? - Answer-Transformer will fail due to an overload Flue vent pipe size is determined by the? - Answer-Appliance manufacturer and IFGC In a split system, the condensing unit is remotely located away from the? - Answer-Thermistor Which electronic control is designed to increase or decrease it's resistance with a change in temperature? - Answer-thermistor Documents that provide information about the hazardous products are ccalled? - Answer-Safety Data Sheet A type B gas vent is? - Answer-Double-walled How many BTu's are required to melt one ton of ice in a 24 hour period? - Answer-288,000 What is replaced when changing a fusible link on an electric heater? - Answer-High limit switch When retro-fitting an R-22 system to a R-407C refrigerant system, it is necessary to change the? - Answer-Lubricant from mineral oil to POE oilWhich condition exists if the heat loss of a structure equals the capacity output of the system? - Answer-The balance point has been reached A combination wiring and crimping tool is used to? - Answer-Cut and strip wire What is the saturation temperature of R-22 at 69 psig? - Answer-40 F If the temperature rise (delta T) of the heat exhanger on a gas furnace exceeds the manufacturers specifications, the technician should do _____? - Answer-increase the motor speed for higher CFM The nominal CFM required per ton of air conditioning is? - Answer-400 Which refrigerant has a zero ozone depletion potential but is still considered a greenhouse gas? - Answer-R134a If a TXV power element loses its charge it results in a? - Answer-Starved evaporator Before using an empty recovery cylinder it should be evacuated to how many microns? - Answer-500 microns The motor shaft rotation direction is located on the? - Answer-Motor nameplate attached to the motor body Using a voltmeter a technician can identify an open contact on a SPST switch in a A/C series circuit by reading? - Answer-Voltage across contacts