Topics: All categories in the pool
1: A class B1 refrigerant is considered
- non-toxic but highly flammable
- non-toxic and non-flammable
- toxic but non-flammable
- toxic and somewhat flammable
2: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 48
- 36
- 18
- 24
3: Three-phase motors have what type of windings?
- three run windings
- three run windings and 3 start windings
- one start winding and one run winding.
- three start windings
4: According to the 522 CMR Board of Boilers, refrigerant detectors, alarms, and the refrigeration mechanical room ventilating systems shall be tested
- annually
- regularly
- quarterly
- bi-annually
5: It takes how many BTU's of latent heat/hr to boil 1 lbs of water into steam?
- 24,000 BTU
- 12,000 BTU
- 144 BTU
- 970 BTU
6: If a purge unit fails on a low pressure chiller, what are the symptoms?
- increased capacity
- high head pressure
- low suction pressure
- low pressure chillers do not have purge units
7: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
- public assembly occupancy
- commercial occupancy
- mixed occupancy
- institutional occupancy
8: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
- it would cause the condenser to sweat
- it would make the condenser less efficient
- it would have no effect on the condenser
- it would make the condenser more efficient
9: What would be the classification for Stop & Shop grocery store?
- Large mercantile
- Place of assembly
- Industrial
- Instituional
10: What is the boiling point of refrigerant governed by?
- P&T relationship
- Condenser sub-cooling
- Compressor RPM's
- Evaporator temperature
11: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- centrifugal switch
- duel-voltage switch
- motor starter
- printed circuit board (PCB)
12: An electronic bridge circuit is basically a
- Wheatstone
- high voltage circuit
- suspension
- 24 volt control circuit
13: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Approved by the authorized person
- Only when combustion air is provided from outside of the machinery room
- Never can be allowed
14: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- moisture in the system
- oil in evaporator
- low head pressure
- not enough oil in the system
15: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
16: Crankcase heaters are energized
- while the compressor is running
- to prevent compressor freeze-up
- when the compressor is off
- to allow easy compressor start-up
17: One watt of electrical energy in a resistive heater will provide _____ BTU/hr
- 3.415
- 34.15
- 16.64
- 6.830
18: Excessive head pressure is often caused by
- leaking reed valve on the discharge side
- air cooled condenser is plugged
- insufficient refrigerant
- thermostat set too high
19: When is the only time you can leave a service container attached to a system?
- Leaking system
- Recovery
- Charging
- Both b and c
20: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 100%
- 80%
- 90%
- 75%
21: Which is considered the more efficient condenser?
- water cooled
- air cooled
- spray cooled
- fan cooled
22: A “U” or “UM” marking a on a nameplate of a pressure vessels signifies compliance with Section VIII of
- the ASME Boiler and Pressure Vessel Code
- Section 11.3.1.5 ASHRAE 15 Standard
- the ANSI Standard 10.7.2
- both the ANSI Standard 10.7.2 and ASHRAE 15 Standard 11.3.1.5
23: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Fan-like action
- Nesting scrolls
- Suction and discharge valves
- Rotating vanes
24: A Lithium-bromide system is an absorption system that
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
25: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.