UNIT 5

Question 1

Used to make sure bearings in motor and driven devices are not overloaded to cause bearing failure.

Answer 1

Belt tension gauge

Question 2

Used to measure vacuum in microns.

Answer 2

Electronic vacuum gauge

Question 3

Used to view areas/items that are not readily accessible.

Answer 3

Inspection mirror

Question 4

Used to measure flue gas compounds such as CO2, O2 and SO2.

Answer 4

Electronic combustion analyzer

Question 5

Used to straighten vent condenser and evaporator fins.

Answer 5

Fin straighteners

Question 6

Can be electronic, halide, soap bubbles, dye or ultrasonic.

Answer 6

Leak detectors

Question 7

Used to install strap clamps around flexible duct.

Answer 7

Nylon strap fastener

Question 8

Used to braze, solder, or weld using an oxygen acetylene gas mixture.

Answer 8

Oxyacetylene unit

Question 9

Used to check relative humidity.

Answer 9

Sling psychrometer

Question 10

Used to remove air and non-condensables from an AC system.

Answer 10

Vacuum pump

Question 11

Can be slipped over tubing to access flare nuts to loosen or tighten.

Answer 11

Flare nut wrench

Question 12

Used to check the flue gas pressure in gas and oil furnaces.

Answer 12

Draft gauge

Question 13

Used to check temperatures. Can be pocket type, glass stem, laser/infrared or digital.

Answer 13

Thermometer

Question 14

Used to measure very high resistances.

Answer 14

Megohmmeter

Question 15

Used to flare ends of copper tubing.

Answer 15

Flaring tool

Question 16

HVAC technician’s primary diagnostic tool used to check pressures in a system.

Answer 16

Gauge manifold

Question 17

Used to cut PVC tubing.

Answer 17

Plastic tubing shear

Question 18

Lever, spring type, or ratchet/gear type used to bend soft tubing.

Answer 18

Tube benders

Question 19

Used to pierce system tubing on hermetically sealed units.

Answer 19

Tube piercing valves

Question 20

True or false
A refractometer is used when retrofitting a mineral oil system with POE oil.

Answer 20

True

Question 21

True or false
A tap is used to make external threads on a section of rigid pipe.

Answer 21

False

Question 22

True or false
A liquid restrictor converts liquid refrigerant into vapor when charging liquid into the suction side of the system.

Answer 22

True

Question 23

True or false
Tin snip handles are color coded to indicate left-turning, right-turning and straight cuts.

Answer 23

True

Question 24

True or false
Combustion testing instruments need to be calibrated each year.

Answer 24

True

Question 25

True or false Non-condensables, air and moisture cause excessive pressures in a refrigeration system.

Answer 25

True

Question 26

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.

Answer 26

False

Question 27

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.

Answer 27

False

Question 28

True or false A rasp is used instead of a file when a larger amount of material needs to be removed.

Answer 28

True

Question 29

True or false A clamp-on meter will give a false reading if two conductors are in the measuring loop/clamp.

Answer 29

True

Question 30

Name two things the vacuum gauge is used for.

Answer 30

*check vacuum pump oil *measures vacuum Also prepares recovery cylinder at 1000 microns

Question 31

In order to attach a flare nut to the end of a piece of copper tubing, what tool(s) must be used?

Answer 31

Flare block, reaming tool, flaring tool

Question 32

When using an adjustable wrench, how is the wrench placed and where is the force exerted?

Answer 32

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

Question 33

When trying to detect a leak by the sound it makes, what tool would you use?

Answer 33

Ultrasonic leak detector

Question 34

Describe what the function of each hose on a 4-valve, 4-hose gauge manifold.

Answer 34

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

Question 35

Rank the following torch gases according to their level of heat produced from high to low (1 to 4). ____. Acetylene ____. Propane ____. Oxyacetylene ____. MAP Pro

Answer 35

2 4 1 3

Question 36

Give an example of sublimation

Answer 36

A substance that gives a phase change such as ice into vapor

Question 37

How many microns in an inch?

Answer 37

25,400 microns in a inch

Question 38

How would you remove moisture from refrigerant in a system?

Answer 38

Use a filter drier

Question 39

Which type of refrigerant has the highest ozone depletion potential?

Answer 39

CFC

Question 40

Which ASHRAE classification means slightly flammable?

Answer 40

A2L

Question 41

Which of the following is an example of a non-condensable? A. Moisture B. Air C. R-12 D. R-134a

Answer 41

B. Air

Question 42

When first inspecting a hermetic system known to be leaking, you should look for _______.

Answer 42

Traces of oil