NATE ICE A C Exam Questions with Certified Answers Graded A+

A compressor does not run, although the condenser fan is operating. Reading the compressor windings, the measured resistance between R to S is 5 ohms, R to C is open, and S to C is open. The problem is due to: - Answer: internal overload being open. A compressor with tight bearings will cause the amperage draw to: - Answer: rise above normal. A correct statement about a hard start kit is that it: - Answer: increases starting torque. A correct statement concerning a relay is that it: - Answer: consists of one or more contacts actuated by a solenoid coil. Across an R-22 suction line drier, how much pressure drop indicates changing the drier? - Answer: 3 psig After a vacuum has been pulled to 500 microns, a pressure rise in a system, followed by a leveling-off at 1500 microns, most likely indicates the: - Answer: presence of moisture. After a vacuum pump has been used, a continuous pressure rise in the system most likely indicates the: - Answer: existence of leak. If the fan switch on a thermostat sub-base is set to ON and the blower motor is cycling on and off, the most probable cause is in the: - Answer: motor overload. In a compressor, the internal overload senses the winding temperature and: - Answer: amperage in the compressor circuit. In a fixed orifice air conditioning system, the presence of non-condensables in the system will cause: - Answer: high head and high suction pressures. In a residence, a slight positive indoor air pressure: - Answer: minimizes infiltration. On initial start-up of an air-conditioning system, the temperature drop measured across the evaporator coil exceeds manufacturer's specifications. This condition most likely indicates a/an: - Answer: lack of refrigerant charge. The control voltage in an air conditioning system comes directly from: - Answer: the secondary of a step down transformer. The function of an external equalizer line for a thermostatic expansion valve is to: - Answer: reference the pressure at the evaporator outlet. The technician is on a spring maintenance check of an air conditioning system. They find the following: *Head pressure is higher than normal, *Suction pressure is higher than normal, *Superheat is 0º F, *Condenser is clean, *Outdoor fan operation is normal, *Subcooling is 25ºF. Which of the following is the most likely problem? - Answer: non-condensables in the system Two places where superheating occurs in a system are the: - Answer: evaporator coil and the compressor. When you are checking the windings of a single-phase compressor with an ohmmeter, the highest ohm reading would be: - Answer: start to run. Which of the following can be caused by insufficient airflow? - Answer: increased compressor failure Which of the following installation steps is necessary to maximize the efficiency of a condensing unit? - Answer: minimum clearances must be maintained around the condensing unit Which of the following is an important factor when selecting a location for placement of a condensing unit? - Answer: should avoid standing groundwater and roof water runoff Which of the following will contribute to customer comfort and cooling system efficiency? - Answer: select equipment based on load calculation