Ua star
A dual-element fuse has:
-two normal one-time fuse links
-a thermal cutout only
-a thermal cutout and a normal fuse link
-the ability to carry locked-rotor current of a motor but not to protect against short
circuits. - answersa thermal cutout and a normal fuse link
The refrigerant line that connects the condenser to the metering device is ___________
line.
-discharge
-expansion
-liquid
-suction - answersliquid
In a three-phase system, the voltage imbalance between any two legs may not vary by
more than:
-10%
-5%
-2%
-1% - answers2%
A hand placed near a hot stove or fireplace is quickly heated by:
-radiation
-convection
-conduction
-refrigeration - answersradiation
If refrigerant condenses at a temperature of 105 degrees F and the water leaves the
condenser at a temperature of 95 degrees F, the ___________.
-condenser approach temperature will be 10 degrees
-condenser approach temperature will be 95 degrees
-evaporator (chiller) approach temperature will be 10 degrees
-evaporator (chiller) approach temperature will be 105 degrees - answerscondenser
approach temperature will be 10 degrees
When using a thermostatic expansion valve with a __________ charged element,
hunting can be considerably reduced.
-gas
-liquid
-cross
,-parallel - answerscross
If you want to replace a defective capacitor but the only replacements you can find do
not have enough capacitance, you can increase their capacitance by:
-connecting two or more capacitors in series
-connecting two or more capacitors in parallel
-increasing the voltage with a potential relay
-reducing the motor current with a current relay - answersconnecting two or more
capacitors in parallel
The difference between a contactor and a motor starter is:
-physical size
-overload protection
-wire size
-timing - answersoverload protection
When an object is refrigerated:
-some of its heat energy is destroyed.
-heat is removed from it.
-more cooling is added.
-its molecules move faster. - answersheat is removed from it.
A single-phase motor in which the starting capacitor remains connected when the motor
runs is called a:
-capacitor-start induction-run motor
-permanent-split capacitor motor
-split-phase motor
-capacitor-start capacitor-run motor - answerspermanent-split capacitor motor
The four main components of a refrigeration system are
-compandium tube, cooler, hot coil, & compressor
-compressor, condenser, evaporator, & metering device
-eliminator, pressure-enthalpy device, refrigerant, & oil separator
-receiver, sight glass, accumulator, and compressor - answerscompressor, condenser,
evaporator, & metering device
Atmospheric pressure at sea level is:
-0 psi
-14.7 psi
-32 psi
-212 psi - answers14.7 PSI
When water is introduced into the end of a chiller it is contained in:
-water boxes
-a combination filter receiver
-a receiver
, -none of the above - answerswater boxes
Heat flows downhill. This means:
-it falls off hot surface to the floor.
-it naturally flows from a colder to a warmer substance.
-heating ducts should flow downhill.
-it naturally flows from warmer to colder substance. - answersit naturally flows from
warmer to colder substance.
In a chiller, the refrigerant boils by ___________.
-absorbing heat from the air passing through it
-absorbing heat from the water passing through it
-rejecting heat to the air passing through it
-rejecting heat to the water passing through it - answersabsorbing heat from the water
passing through it
A lamp source has a voltage of 110 volts and a current of 0.9 amperes. What is the
resistance of the lamp?
12.22
122.2
0.008
0.08 ohms - answers122.2
The device that is incorporated into a vacuum steam heating system to protect the
vacuum pump from creating too low (deep) a vacuum is a:
relief valve
control line
vacuum switch
vacuum breaker - answersvacuum breaker
When a three-phase motor single-phases, it:
draws power from the two remaining phases
draws power from only one phase
always short-cycles
runs cooler - answersdraws power from only one phase
The rotation of a three-phase motor can be reversed by interchanging:
the collector ring
any two leads
the starting winding
the running winding - answersany two leads
The amount of heat removed to lower the temperature of 15 lbs of water from 48
degrees F to 39 degrees F is:
0.0113
135 Btu.
A dual-element fuse has:
-two normal one-time fuse links
-a thermal cutout only
-a thermal cutout and a normal fuse link
-the ability to carry locked-rotor current of a motor but not to protect against short
circuits. - answersa thermal cutout and a normal fuse link
The refrigerant line that connects the condenser to the metering device is ___________
line.
-discharge
-expansion
-liquid
-suction - answersliquid
In a three-phase system, the voltage imbalance between any two legs may not vary by
more than:
-10%
-5%
-2%
-1% - answers2%
A hand placed near a hot stove or fireplace is quickly heated by:
-radiation
-convection
-conduction
-refrigeration - answersradiation
If refrigerant condenses at a temperature of 105 degrees F and the water leaves the
condenser at a temperature of 95 degrees F, the ___________.
-condenser approach temperature will be 10 degrees
-condenser approach temperature will be 95 degrees
-evaporator (chiller) approach temperature will be 10 degrees
-evaporator (chiller) approach temperature will be 105 degrees - answerscondenser
approach temperature will be 10 degrees
When using a thermostatic expansion valve with a __________ charged element,
hunting can be considerably reduced.
-gas
-liquid
-cross
,-parallel - answerscross
If you want to replace a defective capacitor but the only replacements you can find do
not have enough capacitance, you can increase their capacitance by:
-connecting two or more capacitors in series
-connecting two or more capacitors in parallel
-increasing the voltage with a potential relay
-reducing the motor current with a current relay - answersconnecting two or more
capacitors in parallel
The difference between a contactor and a motor starter is:
-physical size
-overload protection
-wire size
-timing - answersoverload protection
When an object is refrigerated:
-some of its heat energy is destroyed.
-heat is removed from it.
-more cooling is added.
-its molecules move faster. - answersheat is removed from it.
A single-phase motor in which the starting capacitor remains connected when the motor
runs is called a:
-capacitor-start induction-run motor
-permanent-split capacitor motor
-split-phase motor
-capacitor-start capacitor-run motor - answerspermanent-split capacitor motor
The four main components of a refrigeration system are
-compandium tube, cooler, hot coil, & compressor
-compressor, condenser, evaporator, & metering device
-eliminator, pressure-enthalpy device, refrigerant, & oil separator
-receiver, sight glass, accumulator, and compressor - answerscompressor, condenser,
evaporator, & metering device
Atmospheric pressure at sea level is:
-0 psi
-14.7 psi
-32 psi
-212 psi - answers14.7 PSI
When water is introduced into the end of a chiller it is contained in:
-water boxes
-a combination filter receiver
-a receiver
, -none of the above - answerswater boxes
Heat flows downhill. This means:
-it falls off hot surface to the floor.
-it naturally flows from a colder to a warmer substance.
-heating ducts should flow downhill.
-it naturally flows from warmer to colder substance. - answersit naturally flows from
warmer to colder substance.
In a chiller, the refrigerant boils by ___________.
-absorbing heat from the air passing through it
-absorbing heat from the water passing through it
-rejecting heat to the air passing through it
-rejecting heat to the water passing through it - answersabsorbing heat from the water
passing through it
A lamp source has a voltage of 110 volts and a current of 0.9 amperes. What is the
resistance of the lamp?
12.22
122.2
0.008
0.08 ohms - answers122.2
The device that is incorporated into a vacuum steam heating system to protect the
vacuum pump from creating too low (deep) a vacuum is a:
relief valve
control line
vacuum switch
vacuum breaker - answersvacuum breaker
When a three-phase motor single-phases, it:
draws power from the two remaining phases
draws power from only one phase
always short-cycles
runs cooler - answersdraws power from only one phase
The rotation of a three-phase motor can be reversed by interchanging:
the collector ring
any two leads
the starting winding
the running winding - answersany two leads
The amount of heat removed to lower the temperature of 15 lbs of water from 48
degrees F to 39 degrees F is:
0.0113
135 Btu.
