Topics: All categories in the pool
1: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 5 amps
- 20 amps
- 15 amps
- 10 amps
2: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
3: Which occupancy can ammonia be used in?
- industrial
- redifential
- depends on the quantity of freon
- commercial
4: Pressure vessels nameplate markings must be compliant with the
- ASHRAE 34 Standards
- CMR-588 & CMR-528
- ASME Boiler and Pressure Vessel Code
- All of the Above
5: Transformers are rated in
- volts
- volts-ohms
- amps
- volt-amps
6: 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
7: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
8: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 45F
- 158F
- 32F
- 155F
9: What is the voltage of each leg of a 480 Volt three-phase motor?
- 277v
- 120v
- 208v
- 240v
10: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
11: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
12: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UM
- UM or UL
- UV or UR
- UL and UR
13: Capacitors are rated in
- kelvins
- megaohms
- micro-farads
- volt - amperes
14: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above
15: The proper location for an oil separator is between the
- condenser and receiver
- receiver and metering device
- compressor and condenser
- evaporator and compressor
16: What type of relief valve is used on a CO2 system?
- fusible plug
- glove disc
- gate valve
- rupture disc
17: Sublimation occurs when
- ice melts and turns to water
- gas is formed directly from a solid
- liquid is formed from a gas
- gas is formed from a liquid
18: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- critical pressure
- low pressure
- design pressure
19: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-1
- A-2
- B-1
- B-2
20: A High-Probablity system
- is such that a leak of refrigerant from failed connections will enter the occupied space
- is a system highly likely to leak from a failed connection or component of such system
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is such that a leak of refrigerant from failed connections will enter the unoccupied space
21: What section governs pressure vessels?
- Section ASHREA 34
- Section 1 ASHREA 15 ASME fired
- Section 8 ASHREA 15 ASME unfired
- OSHA
22: When an electronic bridge is in balance the bridge output will be
- 1 volt
- 15 volts
- .01 volts
- 0 volts
23: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Saturated temperature
- Dry bulb temperature
- Wet bulb temperature
- Critical temperature
24: Total heat of a substance is considered
- empathetical
- enthalpy
- specific heat
- sensible heat
25: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 20'
- There is no minimum for relief valve and windows.
- At least 40'
- At least 30'