Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
the owner shall be informed
no flames shall be permitted
gas masks must be worn
explosion precautions must be taken
2: The two float-type metering devices are the
liquid float and the vapor float
liquid float and the low-side float
high-side float and the low-side float
vapor float and the low-side float.
3: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
9F
21F
11F
29F
4: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
104 ohms
27 ohms
71 ohms
80 ohms
5: Low pressure systems have what kind of compressor?
Rotary
Reciprocating
Scroll
Centrifugal
6: R-22 is classified as a ____ refrigerant on the safety matrix.
A-1
B-2
A-2
B-1
7: 1 Watt = ______ BTU's?
7.216
3.412
12
4.482
8: Brazed joints melt at temperatures above
1,200F
500F
1,000F
800F
9: B3 refrigerants are considered
toxic and highly flammable
non-toxic but flammable
toxic but non-flammable
non-toxic but non-flammable
10: Where are the three places that the discharge from an ammonia relief valve be piped?
atmosphere, tank containing water, where the A.H.J. indicates
underground, into drain, into mechanical room
to chemical neutralizing tank only
none of the above
11: What are the three components of a transformer?
Primary core, secondary coil, and high and low voltage connectors.
Contacts, secondary coil, and core
Primary coil, secondary coil, and copper contacts
Primary coil, secondary coil, and core
12: If a condenser is on a roof and the temperature is 35F and dropping the capacity
decreases
run as designed with low ambient controls
increases
doesn't change
13: The discharge relief valve is located (9.4.6)
on top of the condensor
between the compressor and the stop valve
between the compressor and oil separator
between the compressor and reciever
14: A class B1 refrigerant is considered
non-toxic and non-flammable
non-toxic but highly flammable
toxic but non-flammable
toxic and somewhat flammable
15: A pressure relief should be located at least _______ from windows and doors.
20'
25'
15'
30'
16: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
it is hydroscopic
it traps moisture
viscosity
all of the above
17: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
you can never change refrigerants
Nothing must be done
Place sign, check for leaks, and insulate suction line
Make sure its compatible, notify owner, and notify AHJ.
18: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
load-side of the contactor in
breaker panel in
first disconnect in
24 volt secondary side of the Class 2 transformer to the thermostat
19: How are safety controls wired in a circuit?
Series/parallel
Parallel
Series
Either series or parallel
20: "I" represents _______ in the Watt's law formula.
amperage
watts
voltage
reactance
21: The leaving chilled water set point for comfort cooling is typically?
66
38
45
60
22: What measures gas pressure?
Manometer
Barometer
Hygrometer
Hydrometer
23: To determine the pump size needed for an open cooling tower system, the following must be known,
GPM and balanced head and friction head
GPM, pipe size, and equivalent head.
GPM and friction head
GPM and unbalanced head and friction head
24: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
fusible plug
fusion plug
relief plug
rupture plug
25: A normal operating evaporator temperature of R-22 for air conditioning is typically