Topics: All categories in the pool
1: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above
2: NH3 is
- R-508A
- ammonia
- lithium bromide
- R-718
3: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UM
- UV or UR
- UM or UL
- UL and UR
4: All electrical work done on refrigeration systems must comply with
- OSHA
- NEC and Massachusetts Modifications
- Department of Energy
- ASHREA-15 Section 9.2.1
5: R-22 is considered a(n)
- HCFC
- CFC
- HFC
- HCFCH
6: A cross charged power element on an expansion valve would normally be used in what temperature range?
- -40F to 0F
- 0F-38F
- 30F to 50F
- -100F to -40F
7: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
8: Suction line oil traps should be installed when the condenser is
- located outside the operates in temperatures below 35F
- on the third floor roof and the evaporator is in the basement
- in the basement and the evaporator is on the third floor
- more than 100' away from the evaporator
9: Lithium-bromide, Li-Br, is best characterized as a
- sand
- soil
- salt
- sugar
10: The most common type of motor starter is
- part winding starter
- duel-winding starter
- delts-wye starter
- across the line starter
11: Ammonia belongs to Group
- A-1
- B-2
- B-1
- A-2
12: The dial of a pressure gauge, when installed on the high side of a system be graduated 1.2 times the designed pressure.
- True
- False
13: What is an egress?
- An entrance or exit
- An escape route
- A valve put on the low side of the system to prevent frosting
- A code violation
14: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusible plug
- relief plug
- rupture plug
- fusion plug
15: The oil separator is always inserted in the system
- in the discharge line
- where it can be easily serviced
- in a cool spot
- to prevent oil logging
16: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
17: On a single phase motor, when does the start winding cut out?
- 100% of its RLA speed
- 50% of its RLA speed
- 25% of its RLA speed
- 75% of its RLA speed
18: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
- 240 volts
- 24.0 volts
- 2.40 volts
- 2,400 volts
19: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 18
- 22
- 50
- 33
20: Ammonia systems use ____ pressure to adjust oil pressure
- liquid
- stream
- discharge
- air
21: What type of relief valve is used on a CO2 system?
- fusible plug
- gate valve
- rupture disc
- glove disc
22: Suction valve unloaders afford an effective means of
- evaporator control
- superheat control
- capacity control
- refrigerant control
23: A high side float is a
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
- float type valve that controls the crankcase oil level
- float type switch that stops the compressor when the pressure on the high side becomes too high
- float type valve that controls the amount of refrigerant stored in the receiver
24: The first step in mechanical refrigeration is
- compression
- evaporation
- condensation
- expansion
25: Who is permitted to access a refrigeration machine room?
- Authorized persons only
- Anyone, it's a completely safe area
- Any employee
- Contractors only