Topics: All categories in the pool
1: Heat transferred by conduction from one body to another is done
- via liquids
- via heat rays
- via solids
- via radiation
2: The first step in mechanical refrigeration is
- condensation
- expansion
- compression
- evaporation
3: How much clearance do you need around the perimeter of electrical panels?
- 12"
- 36"
- 24"
- 18"
4: Pressure is the equivalent of
- force per unit area
- area times force
- force
- force times area
5: Each machinery room shall contain
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- high and low pressure controls
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
6: What type refrigerant is NOT ozone depleting?
- CFC
- HCFC
- HFC
- Halon
7: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- too small evaporator
- starved evaporator
- compressor suction valve stuck open
- overcharged
8: 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
9: Which oil is hydoscopic?
- SW30
- polyolester
- mineral
- animal
10: Which of the following is NOT a positive displacement compressor?
- scroll
- centrifugal
- reciprocating
- screw
11: 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
12: 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
13: Total heat of a substance is considered
- empathetical
- enthalpy
- specific heat
- sensible heat
14: What must be done to refrigerant pipes before being buried ?(8.10.4)
- Certified
- Classifed
- Leak checked
- Insulated and installed in a pipe duct (Encased)
15: A rule of thumb in air conditioning is ____ CFM per ton?
- 100
- 600
- 500
- 400
16: Which of the following is a drop-in for R-22
- R-410A
- R-134A
- R407C
- None of the above
17: A cross charged power element on an expansion valve would normally be used in what temperature range?
- 0F-38F
- -40F to 0F
- 30F to 50F
- -100F to -40F
18: How many gallons of water per pound of ammonia do you need?
- 5
- 1
- 20
- 15
19: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- the vapor side of the system
- the liquid side of the system
- low side of the system
- high side of the system
20: A device used to measure small pressure differences is the
- manometer
- phsycometirc
- pyrometer
- anemometer
21: A start capacitor in series with a start winding will
- increase starting torque
- decrease the amp draw of the motor
- increase the amp draw of the motor
- increase running efficiency
22: Setting a pressure relief device shall not exceed ___ of the design pressure
- 75%
- 80%
- 100%
- 90%
23: One ton of refrigeration is defined as ______ btu/minute.
- 200
- 12,000
- 60
- 720,000
24: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- cooling temperature set-point
- adjustment of the spring tension of the TXV
- opening at the pump outlet
- opening at the pump inlet
25: If a purge unit fails on a low pressure chiller, what are the symptoms?
- low pressure chillers do not have purge units
- low suction pressure
- high head pressure
- increased capacity