Topics: All categories in the pool
1: The main cause of enacting the "no vending rule" of July 1st 1992 was
- global warming potential
- ozone depletion
- both a & b
- None of the above
2: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above
3: Liquid level gauges must be provided with what?
- A low level mark
- A red line
- A relief valve
- Automatic shut-offs
4: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Air and dirt
- Water and soap
- Moisture and air
- Oil and water
5: 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
- 43.3 psig
- 66.1 psig
- 50.2 psig
6: Evaporators within 18" of a heating coil must be equipped with a
- low limit control
- zone valve
- pressure relief device
- high limit control
7: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 70F
- 58F
- 77F
- 32F
8: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 27 ohms
- 80 ohms
- 104 ohms
9: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?
- CFM and HP increase
- CFM and HP decrease
- RPM and CFM increase
- CFM and RPM decrease
10: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
11: A cross charged power element on an expansion valve would normally be used in what temperature range?
- -100F to -40F
- -40F to 0F
- 30F to 50F
- 0F-38F
12: A tachometer is an instrument used to measure
- speed
- air velocity
- static pressure
- RPM
13: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
14: A class B1 refrigerant is considered
- non-toxic but highly flammable
- toxic and somewhat flammable
- non-toxic and non-flammable
- toxic but non-flammable
15: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- design pressure
- critical pressure
- low pressure
16: The critical temperature of a refrigerant gas occurs when
- any decrease in pressure will cause condensation
- the gas returns to a liquid
- the gas is no longer saturated
- any increase in pressure will not liquefy the gas
17: Secondary refrigerants are usually
- alcohol
- Prestone anti-freeze
- expensive
- water or brine
18: Adjusting the spring pressure on a TXV
- changes superheat
- changes subcooling
- makes no difference
- adjusts the bulb charge
19: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 33
- 50
- 18
- 22
20: Indirect systems using Group II refrigerants
- shall be used in refrigeration system less than 1,000 lbs
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
- shall be used for mechanical equipment only
- shall be used in refrigeration system in excess of 1,000 lbs
21: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 2%
- 1%
- 4%
- 25%
22: A capacitor in series with the start windings will do what?
- Increase run efficiency by 10% of its rating
- Decrease the RLA to within 10% of its rating
- Increase starting torque
- Nothing
23: Which occupancy can ammonia be used in?
- redifential
- commercial
- industrial
- depends on the quantity of freon
24: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
25: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- A group sensing
- phosgene gas sening
- CO Sensing
- refrigerant sensing