UNIT 5 Flashcards
Used to make sure bearings in motor and driven devices are not overloaded to cause bearing failure.
Belt tension gauge
Used to measure vacuum in microns.
Electronic vacuum gauge
Used to view areas/items that are not readily accessible.
Inspection mirror
Used to measure flue gas compounds such as CO2, O2 and SO2.
Electronic combustion analyzer
Used to straighten vent condenser and evaporator fins.
Fin straighteners
Can be electronic, halide, soap bubbles, dye or ultrasonic.
Leak detectors
Used to install strap clamps around flexible duct.
Nylon strap fastener
Used to braze, solder, or weld using an oxygen acetylene gas mixture.
Oxyacetylene unit
Used to check relative humidity.
Sling psychrometer
Used to remove air and non-condensables from an AC system.
Vacuum pump
Can be slipped over tubing to access flare nuts to loosen or tighten.
Flare nut wrench
Used to check the flue gas pressure in gas and oil furnaces.
Draft gauge
Used to check temperatures. Can be pocket type, glass stem, laser/infrared or digital.
Thermometer
Used to measure very high resistances.
Megohmmeter
Used to flare ends of copper tubing.
Flaring tool
HVAC technician’s primary diagnostic tool used to check pressures in a system.
Gauge manifold
Used to cut PVC tubing.
Plastic tubing shear
Lever, spring type, or ratchet/gear type used to bend soft tubing.
Tube benders
Used to pierce system tubing on hermetically sealed units.
Tube piercing valves
True or false
A refractometer is used when retrofitting a mineral oil system with POE oil.
True
True or false
A tap is used to make external threads on a section of rigid pipe.
False
True or false
A liquid restrictor converts liquid refrigerant into vapor when charging liquid into the suction side of the system.
True
True or false
Tin snip handles are color coded to indicate left-turning, right-turning and straight cuts.
True
True or false
Combustion testing instruments need to be calibrated each year.
True
True or false
Non-condensables, air and moisture cause excessive pressures in a refrigeration system.
True
True or false
When using a 2-valve, three hose manifold gauge to check pressures, the manifold valves must be in the open position for the system pressure to register on the gauges.
False
True or false
The non-contact voltage (NVC) feature on a multimeter can be used to determine between high and low voltage in a circuit.
False
True or false
A rasp is used instead of a file when a larger amount of material needs to be removed.
True
True or false
A clamp-on meter will give a false reading if two conductors are in the measuring loop/clamp.
True
Name two things the vacuum gauge is used for.
*check vacuum pump oil
*measures vacuum
Also prepares recovery cylinder at 1000 microns
In order to attach a flare nut to the end of a piece of copper tubing, what tool(s) must be used?
Flare block, reaming tool, flaring tool
When using an adjustable wrench, how is the wrench placed and where is the force exerted?
Stationery side against nut, pull force is on stationary side.
*wrench is placed or clamp around the nut. Push force is on stationary side
*force exerted in pushing motion to loosen & pulling motion to tighten
When trying to detect a leak by the sound it makes, what tool would you use?
Ultrasonic leak detector
Describe what the function of each hose on a 4-valve, 4-hose gauge manifold.
Yellow hose- charges/recovers refrigerant or nitrogen
Black hose- deep vacuums the system
Red hose- connects to the high pressure side of system- pressure reading
Blue hose- connects to low pressure side of system- pressure reading
Rank the following torch gases according to their level of heat produced from high to low (1 to 4).
____. Acetylene
____. Propane
____. Oxyacetylene
____. MAP Pro
2
4
1
3
Give an example of sublimation
A substance that gives a phase change such as ice into vapor
How many microns in an inch?
25,400 microns in a inch
How would you remove moisture from refrigerant in a system?
Use a filter drier
Which type of refrigerant has the highest ozone depletion potential?
CFC
Which ASHRAE classification means slightly flammable?
A2L
Which of the following is an example of a non-condensable?
A. Moisture
B. Air
C. R-12
D. R-134a
B. Air
When first inspecting a hermetic system known to be leaking, you should look for _______.
Traces of oil
