Download ESCO HEAT PUMP 2025|ORIGINAL 100Qs&As||100% VERIFIED|GRADED A+|NEW UPDATE SUMMER-FALL 2025 and more Exams Electrical Engineering in PDF only on Docsity!
ESCO HEAT PUMP 2025|ORIGINAL 100 QUESTIONS
AND ANSWERS|100% VERIFIED|GRADED A+|NEW
UPDATE SUMMER FALL 2025- 2026
An air-to-air heat pump has many of the same components as an air conditioning system. The major difference is that a heat pump also has an Reversing valve What is the difference between "demand defrost" and "timed defrost"? Demand defrost happens only when needed and timed defrost is based on time/temperature. The thermostat that controls the auxiliary electric heat according to the outdoor temperature is called the; Outdoor ambient thermostat The outdoor temperature at which the heat pump provides the same amount of heat as the heat loss of the conditioned space without an auxiliary heat is known as the; Initial balance point At what temperature is an outdoor ambient thermostat normally set? Slightly above the initial balance point.
The outdoor coil is frozen solid on a "no heat" service call. The most likely reason is; The outdoor fan is inoperative. In order to determine a heat pumps' balance point, you must first calculate; The building's heat load. When a heat pump is used for heating and cooling, the system is sized by the; Cooling load. A high efficiency heat pump system designed to function from high to low ambient conditions below 10*F, may have? Two outdoor coils with each one incorporating a dual stage compressor. Room thermostats for heat pumps should be installed; As near to the main return air grill as possible. When the heat pump compressor has malfunctioned, the customer has the option to switch the system into;
The temperature difference between the 1st and 2nd bulbs for heating on a heat pump thermostat is; Approximately 2*F SEER is calculated by; Dividing the Btu's removed by the watts consumed during the cooling season. If the indoor fan is operated at an excessive speed in the cooling mode; The system will not properly remove the humidity from the conditioned space. The most preferred method of charging any system in the field is; By weight. What is the industry standard for deep vacuum? Maintain 500 microns for 15 minutes. Good service practice for installation of a reversing valve includes; Use heat paste and wet rags while brazing in the new valve. Off-cycle crankcase heat is provide by; A small amount of current is passed through the start capacitor to start the heat winding.
You are checking for proper airflow in CFM on a three ton heat pump system. The system has one return grill measuring 24"X24", which has a net free area of 3.4 square feet. You measure air velocity and calculate an average of 400 FPM. From this information you can conclude that; Airflow in CFM is below normal range. What control operates the 1st stage of secondary heat? The second heating stage of the indoor thermostat. What is the industry standard for maximum duration for defrost? A maximum of 10 minutes. What is the recommended CFM across the evaporator cool of a heat pump? 400 to 450 CFM If manufacturer specifications are not available, a good way to calculate cubic feet per minute through a coil is to; Use temperature rise on emergency heat mode.
Where is the LLP physically located in this system on this heat pump? On the bi-flow liquid line located between the two coils. You are starting-up a split system heat pump for the first time.the outdoor ambient temperature is 60F. You check the temperature split across the indoor coil in the heat mode and find it is 38F. You switch to cooling mode and determine a temperature split of 29*F. The most likely corrective action (relative to airflow) is; Increase the indoor fan speed. Heat pump mode efficiency is rated in; HSPF. On a water source heat pump, the heat mode water regulating valve must be; Direct acting. An R410A heat pump operating in the heating mode has a suction pressure 50 PSIG and head pressure of 285 PSIG has a compression ratio of; 4.6:
Which type of heat pump does not require a defrost cycle? Water source. An R-410A heat pump operating in the cooling mode has a suction pressure of 131 PSIG. Adding 2 PSIG for pressure drop in the coil, the true outlet pressure is 131 PSIG. The temperature of the suction line at the outlet of the evaporator is 57° F. What is the superheat? 12 Degrees On a time initiation/temperature termination defrost, the defrost time clock has one N.O. And N.C. switch. When do the positions of these switches change? Every 30 or 90 minutes, depending on the cam installed in the timer. What would be the result of closing registers in rooms that are uninhabited while operating in the heating mode? The discharge pressure and temperature will rise decreasing the life span of the unit. What is the most common complaint from a customer changing from gas heat to a heat pump? Cold air at high velocities coming out of the registers.
Some heat pump systems use a ______________ as a metering device. Fixed orifice. The slide valve and piston in the reversing valve is actuated by pressure directed through the; Solenoid and pilot valve. During the heating cycle, the outdoor coil is use as; The evaporator. During the cooling cycle, the indoor coil becomes; The evaporator. During the defrost cycle, the outdoor fan is usually; Turned off. Heat pump systems which use a thermostatic expansion valve at each coil will also have; A by-pass lines with check valves.
Refrigerant flow through the compressor; is always the same regardless of operating mode. Because of the possibility of liquid flood-back, a heat pump that uses a reciprocating compressor should be equipped with a; Suction Accumulator. A scroll type compressor; is less susceptible to damage from liquid flood-back. On a split system heat pump. A "no heat/no cooling" service call, you turn the thermostat to the fan on/ cont position and the indoor fan operates. This action verifies that; The transformer is functioning. On most air-to-air heat pumps; The indoor and outdoor coils are the same size and physical capacity.
The reversing valve must switch to cooling mode, the outdoor fan shuts off and auxiliary heat is energized. High suction pressure and low discharge pressure on a heat pump system operating in either the heating or cooling mode can be an indication of; Compressor inefficiency. The preferred method to preform adjustments to the refirgerant charge in a heat pump system is in the ________ more. Cooling. You answer a service call for insufficient heat. You find the suction pressure is higher and discharge pressure is lower than normal. Using a digital thermometer, you measure the line entering the reversing valve from the compressor discharge and find 215°F. You then measure the line leaving the reversing valve that connects to the indoor coil and find 185°F. These readings are an indication of; A faulty reversing valve. The customer complaint is not enough heat. You install service gauges and find the low side pressure is higher than normal and the high side pressure is lower than normal. You switch to the cooling mode and find the pressures are normal. The most likely cause of the problem is;
A stuck open check valve at the outdoor coil. A customer complains that their heat pump systems blows cool air periodically during the heat mode. This could be caused by; A faulty defrost relay (does not energized the aux. heat during the defrost mode.) When a heat pump is in the heating mode, which can cause frost accumulation on the outdoor coil when the ambient temperature is 45*F? The outdoor coil is colder than the ambient air. The indoor fan on a heat pump system operates; At the same speed for heating or cooling; The defrost cycle can be initiated by; Time and temperature. The defrost cycle can be terminated by; Time/temperature
On Dual Fuel Systems, the indoor coil must be located; After the heat exchanger. Air-to-air heat pumps are most practical to operate in areas where the lowest winter temperature does not go below ______ *F
Air-to-air heat pumps, operating without auxiliary heat, provide air to the registers that is approximately _______ *F or less. 100 The most common method of defrosting the outdoor coil on an air source heat pump is; Reverse cycle defrost. COP is the abbreviation for; Coefficient of performance. At temperatures above 45 degrees *F, the heat pump refrigeration cycle permits the;
Condenser to release 3 to 4 times more heat than it takes in electrical energy to drive the compressor. In addition to heat from the outdoor coil, a heat pump in the heating mode will get heat from; Compression. When operating in the heat mode, hot gas leaves the compressor and first flows to; The reversing valve. When operating in the cooling mode, hot gas leaves the compressor and first flows to; The reversing valve. To make the reversing valve slide move, the system must have a pressure difference of; 75 to 100 PSIG Before connecting a manifold gauge set to a heat pump system, you should first;
One of the most important devices to insure the longevity of a heat pump's reciprocating compressor is the; Crankcase heater. A heat pump can be difficult to charge properly because; Heat pumps can only be charged in the cooling mode. High efficient heat pump systems charged with R-410A refrigerant normally use a; Fixed orifice metering device for the heating cycle and a TXV for the cooling cycle. When a heat pump is operating in the cooling mode, the; Indoor metering device is metering refrigerant and the outdoor check valve is open. When in the cooling mode, the low pressure refrigerant vapor leaves the reversing valve and tracked to the; Accumulator and then to the compressor.
