Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The actual expansion curve of compression follows most nearly which one of the following curves?
Adiabatic
Pressure Temperature
Isothermal
Volume Temperature
2: The most common type of motor starter is
across the line starter
part winding starter
duel-winding starter
delts-wye starter
3: A low oil switch is typically
time-delay auto reset
non used on semi-hermetic compressors over 10 ton capacity
manual reset
automatic reset
4: What is the boiling point of refrigerant governed by?
P&T relationship
Compressor RPM's
Evaporator temperature
Condenser sub-cooling
5: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
24
50
75
100
6: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
977.6 watts
9.776 watts
9,776 watts
.9776 watts
7: Which winding have the most turns?
depends on the motor phase
Start
they have equal amount of turns
run
8: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
lift voltage
run voltage
boost voltage
pick-up voltage
9: What is the amp draw of a 40 VA transformer at 24 volts
106 amps
1K amps
1,000 amps
1.6 amps
10: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.
55
15
50
75
11: R-22 is classified as a ____ refrigerant on the safety matrix.
A-2
B-1
B-2
A-1
12: A restaurant is classified as a
large mercantile occupancy
mixed occupancy
commercial occupancy
public assembly occupancy
13: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
orange
red
blue
green
14: "R" represents ___ in the Ohm's law formula
amperage
resistance
capacitance
voltage
15: What was the main reason for enacting the no venting rule of July 1, 1992?
Ozone depletion
Green house effect
Global warming potential
All of the above
16: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
it would make the condenser more efficient
it would make the condenser less efficient
it would have no effect on the condenser
it would cause the condenser to sweat
17: Capacitors are rated in
micro-farads
volt - amperes
kelvins
megaohms
18: Stop valves shall not be permitted between the system and the
bleed valve
service valve
condenser
relief valve
19: A High-Probablity system
is such that a leak of refrigerant from failed connections will enter the occupied space
is such that a leak of refrigerant from failed connections will enter the unoccupied space
is such that any leak will cause injury or death to anyone within a 100 square foot area
is a system highly likely to leak from a failed connection or component of such system
20: Direct systems using Group II refrigerants
shall not be used for air condition for human comfort
shall be installed per instruction of the AHJ
shall be installed in Class T machinery rooms
shall be allowed to be used for human comfort.
21: Halo-carbon refrigerants cannot be used with what material?
Copper
Magnesium alloy
Stainless Steel
Aluminum
22: Liquid line filter-driers on a 410A system must be rated for no less than
400 psig
600 psig
1000 psig
200 psig
23: What is the minimum size wire you can use on a 30 amp circuit?
12 AWG
16 AWG
14 AWG
10 AWG
24: How many forces operate a thermostatic expansion valve?
3
4
1
2
25: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.