Talon Nate Heat Pump 1 with complete verified solutions

What is a thermal equilibrium point of a duel fuel heat pump? Outdoor conditions which the capacity of a single heat pump matches the capacity of a supplementary heater Which ACCA manual should the technician consult to make an accurate calculation of residential load? ACCA J Manual What is the minimum ampacity of a circuit listed on the data plate of a packed heat pump used to determine? The average amperage of equipment when it is working properly What is the relationship between the input current and the holding current of a delay coil? Input current starts time delay relay timer, holding current starts relay Only one accumulator from the suction line should be used in a residential heat pump as recommended by the manufacturer. Yes? Extending refrigerant lines increases the system charge above the maximum recommended charge. Which of the following operations is an important reason to use Electronic controls? Electronic Controls can make decisions based on many inputs of information Generally, heat pumps are sized for the conditioned space based on? Cooling load What is an effective method to reduce noise transmissions from the air handler installed in a closet? Keep cabinet on insulation pad Ability of programmable electronic thermostats to set the set point so the temp reaches that point at a specified time Computed recovery How do controls use those two temperatures to determine if it is necessary to defrost? As the coil freezes, the temperature difference between the coil and outside air increases In accordance to fire protection codes, when should dampers be used? In any air duct that passes through a fire retardant wall for two hours When wiring 20 amperes motor (FLA), the minimum circuit ampacity (MCA) must be 25 What is the typical method to determine the stages of a two-stage compressor in a heat system? A deviation from the thermostat set point The thermostatic expansion valve does what to maintain the flow of refrigerant to a condenser? Maintains superheat of refrigerant coming out of the condenser. What do Electronic air cleaners not eliminate? Smells or odors The purpose of a sequencer in a 20KW auxiliary electric heater is to energize? First to energize all heating elements, then to the fan What is the TXV's job Maintain constant superheat The coefficient of performance (COP) of a heat pump is? The total electric input in watts divided by the output in watts Low pressure limit controls are often placed in the suction line of a heat pump for which two purposes To protect compressor if suction pressure drops and to detect pressure drop The diameters and lengths of the R-22 steam lines are generally specified for a drop in steam pressure that should not exceed what value? -2 to 3 PSI or 2°F (-16°C) To consider that an evacuation is complete, the refrigerant circuit of a heat pump must be evacuated to a minimum of? 500 microns What is important to take into account when bending soft copper pipes in a double of any angle? The cross-sectional area of the tube should not be significantly reduced. ( so that it doesn't kink) Which of the following positions should mount the thermostatic expansion valve sensing bulb to more accurately measure the temperature of the suction lines are 1 1/8 inches (6.8cm) or higher. 4 or 8 o' clock A disc type pressure control, closing on rising is used as a pressure drop limit control in the liquid line of a heat pump. The control must feel the specified pressure within the 15 seconds of compressor startup for the compressor to continue operating. If the control cutoff setting deviates downward. What does this mean for system performance? The system is less likely to shut down as a result of a small leak What can cause a system purged to 500 micron to show a immediate & continuous increase in pressure when the valve of the vacuum pump is off? There is a leak in the system What happens if the residue from defrosting does not drain properly? Excess water will create an electrical hazard. What is used to measure the static pressure of a duct? Differential pressure gauge. The component used to transmit sound and prevent water leaks from a heat pump installed on a roof is? Edge Joint (curb gasket) The impulse stats are generally installed in what place of the rectangular duct? On the Horizontal Side To correctly adjust a heat anticipator is it necessary to check? The measurement of the amperage of the control circuit in the heating. Generally, an electronic leak detector detects a leak as small as: 1/2 OZ (14 grams/year) How will a technician determine the voltage drop of an outdoor unit of a heat pump using a voltmeter? With the outdoor unit not working (powered off) and then with the outdoor unit running. (powered on) When verifying the pressures in an operating system with a distributor assembly, the refrigerant oil in a Hose: Until all the readings at that distributor decrease in value. A technician measures the temperature of the return air from a stove with an output of 100,000.000 BTU's at 65°F (18°C) And the supply side air temperature at 135°F (57°C). What are the SCFM's (standard CFM) 1323 The best way to fix a noisy residential supply diffuser due to a loose vane is..? Replace the diffuser. Undersized ducts often produce..? High noise levels, insufficient air quantities, and high static pressure. What is the effect of a 170V supply to a 208V or 220V compressor? The current increases and the motor may become overloaded. What is the temperature of your cooling for an R-22 unit with a high side pressure of 260 PSIG, a low side pressure of 68 PSIG and a temperature in the liquid line of 90°F (32°C) -30°F Where is the sensor of an outdoor thermostat generally installed for in a heat pump system? In the incoming air stream to the outer coil The following measurements were recorded in a heat pump system that is working, the heat pump is working only with the compressor without auxiliary heat. -The supply air temperature for the heat pump is only 90°F (33°C) -The return air temperature for the heat pump is only 70°F( 21°C) -Outdoor temperature of 54°F (12°C) -Auxiliary heat / supply air temperature on 115°F (46°C) -The return / auxiliary heat temperature is 70°F (21°C) -CFM 1228 What is the capacity of the heating system in BTU's? 29,177 BTU/ H Electronic air cleaners can operate with internal voltages as high as? 5,000 V What is the purpose of an AUTO convection system switch on the thermostat of a heat pump? Automatically switch between heating and cooling as the load changes. What type of fan is the most commonly used in a residential system? Fan with propellers (axial) What measurements are necessary to determine the super low side heat? The suction pressure and the temperature of the suction line. A high pressure limit control used to turn off a compressor, if the condensing pressure is excessive, it is generally installed to measure? compressor discharge line pressure In heating, the hoses of the low and high side of distributor set are connected to the distribution connections of the service valve of the vapor and the liquid lines in the set of lines of a correctly loaded heat pump. What would the approximate distribution readings be if R-22 is the refrigerant charge with an outdoor temperature of 50°F low side=190 PSIG High side 70 PSIG Possible high side of manifold damage When does the load on a heat pump in cooling mode decrease, the section pressure? Low and discharge pressure low What three things happen when a heat pump enters its defrost mode? reversing valve switches to cooling mode, the external fan is turned off, and the auxiliary heat is powered. To which terminals of a single stage compressor is the coil of a power relay connected? Common and Home(start)terminal. A technician encounters the following conditions while checking a packaged heat pump while its cooling -The unit has a piston type measuring device in the condenser or evaporator. -An outdoor temperature of 75°F (24°C) -A super heat of 55°F (13°C) What is the correct diagnosis and action? Unit is low load and load needs to be added A reason for claims for cold air when a heat pump works in the heating cycle is..? That the supply air ventricles is excessive. When performing maintenance on a heat pump, the technician should check the outdoor fan to make sure what? The fan runs freely without joints or vibrations. With a R-410A condensing pressure of 276 PSIG and a liquid line temperature of 108°F (42°C). What is the sub-cooling temperature? 24°F (-4.44°C). Why do some electronic thermostats require connections on the hot side and common side of the low voltage of transformer Use both R and C to power the display thermostat screen light Why does an outdoor fan of a heat pump stop during defrosting? To minimize thawing time. Generally, the reversing valves for heat pumps are manufactured with 4 refrigerant circuit tubes welded to the valve body. One of the tubes is welded to one side of the body and the three tubes are welded to the opposite side. What parts of the circuit is generally.... Discharge line How does a technician check the motor winding of a compressor that is suspected to be grounded in the compressor casing? (Assume all power to the unit is off and the wires have been removed from the compressor and its terminals) Check the continuity between the compressor terminals and the ground with an ohmmeter What is the effect on the supply air flow used by a PSC fan motor when the static pressure of the return is reduced? Air flow increases What effect would an insufficient voltage or current have on a solenoid valve? The valve would vibrate or grind. What can produce a suction pressure lower than normal? A restricted dryer Why are there more circuits in the outer evaporator of a heat pump than in the outer evaporator of an AC condenser? Because the pressure drop in the outer coil of a heat pump must be minimized. What describes the path of the air flow of an outdoor condenser that passes through? Air moving vertically up through the fins and out through the top. According to the manufacturer's recommendations, the most acceptable method to connect a set of lines to the evaporator is..? The use of 95-5 soft solder and the correct flux.