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HVAC Excellence - ELECTRICITY
Exam | NEWEST EXAM 2026
Current flow is: - ANSWER The flow of electrons in the circuit. Impedance is: - ANSWER Opposition to alternating current flow. Like charges; - ANSWER repel each other. Any material that will readily release electrons is called; - ANSWER A conductor The symbol for current is; - ANSWER I Which of the following materials would be best suited for use as a semi-conductor? - ANSWER silicon The safety ground conductor is usually color coded; - ANSWER green or bare. An electron has; - ANSWER a negative charge. Resistance is: - ANSWER Opposition to current flow. How many watts of power are used by a heater operating at 240 volts and drawing 5 amps? - ANSWER 1200 watts Which of the following meters must use its internal power to check a load or circuit? - ANSWER Ohmmeter In electrical wiring, a black colored wire in an alternating current circuit usually indicates;
- ANSWER the hot conductor. Fuses are sized by: - ANSWER Volts & Amps What would be the result, if a 24 volt, 20-ohm low voltage conta ctor coil were wired in series with a 24 volt, 200-ohm control relay coil? - ANSWER Only the control relay would operate. Three defrost heaters, each 15 ohms are wired in parallel to a 120 volt power supply. How many watts of power will be used? - ANSWER 2880 Watts Which of the following is generally considered to be within the maximum allowable (plus or minus) supply voltage variation? - ANSWER 5% Capacitors are rated in - ANSWER Microfarads & Volts.
When testing a capacitor with an analog or digital ohmmeter, the meter should; - ANSWER measure low resistance then return to high reading. What is the term used to describe the output side of a transformer? - ANSWER Secondary side. One horsepower is equal to __________ watts. - ANSWER 746 How much resistance must be placed in a 120 volt circuit in order to limit the current to 2 amps? - ANSWER 60 Ohms A parallel circuit contains a 18 ohm and a 9 ohm resistor. The total resistance equals; - ANSWER 6 ohms. In a series circuit, the voltage drop across each resistance (load) will. - ANSWER add up to equal the source voltage. The total resistance of a parallel circuit will be; - ANSWER less than the smallest resistance. Which of the following statements about current is true? - ANSWER Current flow will increase when voltage increases. When resistors are wired in parallel; - ANSWER the voltage drop across each resistor will be the same as the applied source Which of the following is equal to 2.1KW? - ANSWER 2,100 Watts Which of the following is equal to 100 milliamps? - ANSWER 0.10 amperes A capacitor analyzer is designed to read; - ANSWER the capacitive resistance of a capacitor. On an electronic oil safety switch what changes the pressure singal to electrical signal?
- ANSWER Transducer. The electric meter on a house measures the ______________ passing th rough it. - ANSWER wattage A three phase load requires a minimum of; - ANSWER three supply lines. Which of the following is the correct formula for determining wattage in an electrical circuit? - ANSWER W = E times I
Single phase motor speed is determined by the. - ANSWER number of stator poles. The capacitor start-capacitor run (CSCR) motor provides; - ANSWER high starting and running torque. To change direction of rotation of a three phase motor. - ANSWER change the position of any two supply wires. Capacitors are always connected _____________ to the start winding. - ANSWER in series Which meter is used to bench check a motor for shorts or open windings? - ANSWER ohmmeter. A solenoid valve coil operates on the principle of - ANSWER electromagnetism. When checking the windings of a three phase motor; - ANSWER all three terminals should show the same resistance. When testing the windings of a single phase motor, - ANSWER the common to run terminals show the lowest resistance. Direct Digital Control (DDC) is - ANSWER electronic controls use for equipment operation and monitoring A step up transformer increases; - ANSWER voltage. Transformers are rated according to; - ANSWER VA at the secondary. Utility companies usually supply residential homes with ______________ service. - ANSWER 240V, single phase, three wire What connects to the terminals T1, T2, & T3 on a contactor or motor starter? - ANSWER Load connections Circuit breakers & fuses are primarily used to provide; - ANSWER protection from an overload of current. Excessive current can be caused by; - ANSWER short circuit. A device with overload protection used to control a motor is a; - ANSWER line starter. Relays are generally used to control inductive loads up to __________ amps. - ANSWER 10
Contactors are rated according to the maximum amperage through the; - ANSWER contacts. What is the minimum number of wires required between two Start/Stop push button controls? - ANSWER 3 If contacts become badly pitted, it is acceptable to. - ANSWER replace the contacts or control The thermal overload contacts on a line starter are usually_______________ reset. - ANSWER manual The ______________ drawing illustrates where the components are located in small appliances. - ANSWER pictorial Which of the following motors is most energy efficient. - ANSWER ЕСM On a good single-phase compressor motor, which winding terminals have the highest resistance? - ANSWER run to start. When testing a motor with an ohmmeter, the following measurements are recorded, Common to run 4 ohms, Common to start 6.2 ohms, Run to start 10.2 ohms, and Common to ground 20.4; This indicates a/an; - ANSWER grounded condition. With a motor running at full load, voltmeter leads are placed on L1 and T1 terminals of the contactor. The voltmeter indicates no measurable voltage. This is an indication of. - ANSWER good clean contacts. When the temperature of a negative temperature coefficient (NTC) thermistor increases, its resistance will. - ANSWER decrease. When the temperature of a positive temperature coefficient (PTC) thermistor increases, its resistance wilI; - ANSWER increase. A transducer can create a signal based on. - ANSWER pressure. A typical thermocouple used on a gas furnace can. - ANSWER generate a small DC electrical current. To discharge a capacitor prior to ohmmeter testing. - ANSWER use a 20,000 ohm, 2 to 5 watt resistor across the terminals. Which of the following is an acceptable temporary replacement for a run capacitor rated at 35MFD @ 440VAC - ANSWER 37.5MFD @ 440VAC.
are short cycling. The blower motor is not running. When the fan switch at the thermostat is moved from the AUTO position to the FAN ON position, the blower runs. This could be caused by. - ANSWER a faulty thermostat - AUTO / FAN ON switch. In the schematic, the crankcase heater will operate; - ANSWER when the compressor is off. in the schematic, the coil on line #11 does NOT control. - ANSWER the blower motor. In the schematic, the coil on line #12 controls the. - ANSWER blower motor relay. In the schematic, if the fuse in L2 is blown the. - ANSWER blower motor will continue to operate. In the schematic, with the thermostat bulb closed, what voltage would be found from Terminal Y to the Common side of the Contactor Coil on Line #11? - ANSWER 24 Volts In the schematic, with the thermostat bulb closed and the fan switch in the AUTO position, what voltage would be found from Terminal R to Terminal G on the Thermostat? - ANSWER 24 Volts How many Watts of Power are used by a heater operating at 460 Volts and drawing 5 Amps? - ANSWER 2,300 Watts Two 120 volt incandescent light bulbs are wired in series, one is a 60 watt bulb, the other is a 4 watt bulb. The result would be - ANSWER both bulbs light A 240 Volt, 3 wire circuit can be split into two 120 Volt circuits. - ANSWER TRUE Which of the following in not a factor in determining impedance in an AC circuit? - ANSWER Frequency When current flows, a _______________ is produced around the conductor. - ANSWER magnetic field Technician #1 says that an open transformer coil is indicated by a reading of infinity on an analog ohmmeter. Technician #2 says that a shorted transformer coil is indicated by a reading of infinity on an analog ohmmeter. Which technician is correct, or are both technicians correct? - ANSWER Technician # only The terminals T1, T2, & T3 are located at the _______ of a contactor. - ANSWER top
Circuit fuses and breakers are primarily used to protect - ANSWER loads
