HVAC EXCELLENCE COMPREHENSIVE UPDATED EXAM
QUESTIONS AND SOLUTIONS RATED A+
✔✔A solenoid valve coil operates on the principle of - ✔✔electromagnetism.
✔✔When checking the windings of a three phase motor; - ✔✔all three terminals should
show the same resistance.
✔✔When testing the windings of a single phase motor, - ✔✔the common to run
terminals show the lowest resistance.
✔✔Direct Digital Control (DDC) is - ✔✔electronic controls use for equipment operation
and monitoring
✔✔A step up transformer increases; - ✔✔voltage.
✔✔Transformers are rated according to; - ✔✔VA at the secondary.
✔✔Utility companies usually supply residential homes with ______________ service. -
✔✔240V, single phase, three wire
✔✔What connects to the terminals T1, T2, & T3 on a contactor or motor starter? -
✔✔Load connections
✔✔Circuit breakers & fuses are primarily used to provide; - ✔✔protection from an
overload of current.
✔✔Excessive current can be caused by; - ✔✔short circuit.
✔✔A device with overload protection used to control a motor is a; - ✔✔line starter.
✔✔Relays are generally used to control inductive loads up to __________ amps. -
✔✔10
✔✔Contactors are rated according to the maximum amperage through the; -
✔✔contacts.
✔✔What is the minimum number of wires required between two Start/Stop push button
controls? - ✔✔3
✔✔If contacts become badly pitted, it is acceptable to. - ✔✔replace the contacts or
control
, ✔✔The thermal overload contacts on a line starter are usually_______________ reset.
- ✔✔manual
✔✔The ______________ drawing illustrates where the components are located in small
appliances. - ✔✔pictorial
✔✔Which of the following motors is most energy efficient. - ✔✔ЕСM
✔✔On a good single-phase compressor motor, which winding terminals have the
highest resistance? - ✔✔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; - ✔✔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.
- ✔✔good clean contacts.
✔✔When the temperature of a negative temperature coefficient (NTC) thermistor
increases, its resistance will. - ✔✔decrease.
✔✔When the temperature of a positive temperature coefficient (PTC) thermistor
increases, its resistance wilI; - ✔✔increase.
✔✔A transducer can create a signal based on. - ✔✔pressure.
✔✔A typical thermocouple used on a gas furnace can. - ✔✔generate a small DC
electrical current.
✔✔To discharge a capacitor prior to ohmmeter testing. - ✔✔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 - ✔✔37.5MFD @ 440VAC.
✔✔The synchronous speed of a four pole, 60 Hz single phase motor is; - ✔✔1800 rpm.
✔✔The symbol for a heating thermostat is represented by diagram. - ✔✔B
✔✔The symbol for a pressure switch that closes on pressure rise represented by
diagram - ✔✔A
QUESTIONS AND SOLUTIONS RATED A+
✔✔A solenoid valve coil operates on the principle of - ✔✔electromagnetism.
✔✔When checking the windings of a three phase motor; - ✔✔all three terminals should
show the same resistance.
✔✔When testing the windings of a single phase motor, - ✔✔the common to run
terminals show the lowest resistance.
✔✔Direct Digital Control (DDC) is - ✔✔electronic controls use for equipment operation
and monitoring
✔✔A step up transformer increases; - ✔✔voltage.
✔✔Transformers are rated according to; - ✔✔VA at the secondary.
✔✔Utility companies usually supply residential homes with ______________ service. -
✔✔240V, single phase, three wire
✔✔What connects to the terminals T1, T2, & T3 on a contactor or motor starter? -
✔✔Load connections
✔✔Circuit breakers & fuses are primarily used to provide; - ✔✔protection from an
overload of current.
✔✔Excessive current can be caused by; - ✔✔short circuit.
✔✔A device with overload protection used to control a motor is a; - ✔✔line starter.
✔✔Relays are generally used to control inductive loads up to __________ amps. -
✔✔10
✔✔Contactors are rated according to the maximum amperage through the; -
✔✔contacts.
✔✔What is the minimum number of wires required between two Start/Stop push button
controls? - ✔✔3
✔✔If contacts become badly pitted, it is acceptable to. - ✔✔replace the contacts or
control
, ✔✔The thermal overload contacts on a line starter are usually_______________ reset.
- ✔✔manual
✔✔The ______________ drawing illustrates where the components are located in small
appliances. - ✔✔pictorial
✔✔Which of the following motors is most energy efficient. - ✔✔ЕСM
✔✔On a good single-phase compressor motor, which winding terminals have the
highest resistance? - ✔✔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; - ✔✔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.
- ✔✔good clean contacts.
✔✔When the temperature of a negative temperature coefficient (NTC) thermistor
increases, its resistance will. - ✔✔decrease.
✔✔When the temperature of a positive temperature coefficient (PTC) thermistor
increases, its resistance wilI; - ✔✔increase.
✔✔A transducer can create a signal based on. - ✔✔pressure.
✔✔A typical thermocouple used on a gas furnace can. - ✔✔generate a small DC
electrical current.
✔✔To discharge a capacitor prior to ohmmeter testing. - ✔✔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 - ✔✔37.5MFD @ 440VAC.
✔✔The synchronous speed of a four pole, 60 Hz single phase motor is; - ✔✔1800 rpm.
✔✔The symbol for a heating thermostat is represented by diagram. - ✔✔B
✔✔The symbol for a pressure switch that closes on pressure rise represented by
diagram - ✔✔A
