Topics: All categories in the pool
1: One ton of refrigeration is defined as ______ btu/minute.
- 60
- 200
- 12,000
- 720,000
2: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 18
- 48
- 24
- 36
3: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 70.8 psig
- 66.1 psig
- 50.2 psig
- 43.3 psig
4: 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
- pick-up voltage
- lift voltage
- boost voltage
- run voltage
5: Gauge pressure is
- Absolute pressrue
- Atmospheric pressure
- Force of pressure above that of atmosphere
- Barometric pressure
6: Low ambient controls are used when
- always
- when systems run all year round
- on air conditioning systems only
- economizers are used
7: What is a Category "M" fluid?
- Any fluid that exceeds 150 psig and has design temperatures over 366F
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily content
- A typical refrigerant used on newer air conditioning and heat pump systems
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and the designed temperature is between -20F to 366F
8: The main purpose of the accumulator is to
- prevent liquid slugs at the compressor
- provide space for the accumulation of oil and containminants
- store liquid refrigerant
- provide space for vapor to accumulate
9: What is the minimum size of the discharge pipe?
- Same size as the outlet of the relief valve
- One pipe size larger that the inlet of the relief valve
- Depends on size of manifold
- All of the above
10: How many flammability classifications are refrigerants in?
- 2
- 5
- 7
- 3
11: A room having machinery but no flame producing apparatus permanently installed and operated is considered a
- Class B machinery room
- Class M machinery room
- Class A machinery room
- Class T machinery room
12: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Low pressure
- Cascade
- R-414B
- Simple
13: The External equalizer of a TXV compensates for
- pressure within the evaporator
- pressure within the system
- pressure drop across the condenser coil
- pressure drop across the evaporator coil
14: What type refrigerant is NOT ozone depleting?
- HCFC
- CFC
- HFC
- Halon
15: "R" represents ___ in the Ohm's law formula
- resistance
- amperage
- capacitance
- voltage
16: Who authorizes changes to the safety codes?
- Board of Boilers
- Person who pulled the permit
- Contractor who last serviced the system.
- Person in charge of the facility
17: Where is the high-side float located on a chiller system?
- inside the chiller barrel
- flash line
- discharge line
- liquid line
18: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
19: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 18
- 24
- 10
- 15
20: When the compressor is below the condensor
- traps are needed on the discharge line
- traps are needed on the suction line
- traps are needed on the oil return line
- traps are not needed on this type of system
21: A start capacitor is wired in _____ with the start windings.
- series-parallel
- series
- parallel
- junction
22: How many closing forces operate a thermostatic expansion valve?
- 4
- 2
- 1
- 3
23: How are safety controls wired in a circuit?
- Either series or parallel
- Series
- Parallel
- Series/parallel
24: Which refrigerant is lighter than air?
- R-11
- R-134a
- R-717
- R-123
25: Which creates more of a heat load?
- 50% RH
- 30% RH
- 90% RH
- 70% RH