Air conditioning Testing and service part A

Question 1

when exposed to exposed flames refrigerants that contain fluorocarbons break down and produce

Answer 1

dangerous poisonous vapours

Question 2

what is the maximum filling limit for any refrigerant container is

Answer 2

80% of its internal volume

Question 3

what is a vapour analyzer able to do

Answer 3

identify and measure the purity of air conditioning system refrigerants , determine the percentage of air contained in the air conditioning system , prevent the filling of refrigerant recovery bottles with cocktails

Question 4

what color is the high pressure side

Answer 4

red

Question 5

what color is the low pressure side

Answer 5

blue

Question 6

what pressure range would be present on the high pressure side

Answer 6

0 - 500 psi

Question 7

what pressure would be present on the low pressure side

Answer 7

0 - 150 psi

Question 8

what could the yellow hose on the gauge set be used for

Answer 8

recover refrigerant from the air conditioning system.
pressure test ( leak check ) with nitrogen.
evacuate air and moisture from the system.
add oil to the air conditioning compressor with oil injector.
recharge the air conditioning system with refrigerant.

Question 9

what is the purpose of using a high capacity vacuum pump when servicing an air conditioning system

Answer 9

to remove the moisture and air that is hidden in the hoses and components of a air conditioning system

Question 10

what can a micron gauge be used for

Answer 10

to measure the level of vacuum that has been reached in the air conditioning system as its being evacuated

Question 11

how can you check the accuracy of the bubble crimp produced on a bead lock fitting that looks regular

Answer 11

you can check it with a micrometer

Question 12

what would you use to fix the bent fins on a air conditioning condenser

Answer 12

a fin comb

Question 13

what would a damaged or loose Schrader valve core cause

Answer 13

a refrigerant leak large enough to render an air conditioning system useless in a matter of hours

Question 14

what is the first step to trouble shooting an HVAC system

Answer 14

visual inspection

Question 15

properly operating air conditioning system temperatures and pressures vary with

Answer 15

ambient temperatures - humidity levels and condenser size

Question 16

what will a blockage to refrigerant flow ( internal restriction ) cause inside the air conditioning system

Answer 16

low system pressure will result

Question 17

what would a malfunctioning air compressor cause

Answer 17

higher than normal low side pressure readings
lower than normal high side pressure readings
high temperature readings in HVAC duct airflows

Question 18

what could two or more refrigerants mixed inside the same air conditioning system cause

Answer 18

high pressure readings

Question 19

what would dirt and debris lodged in the condenser fins cause

Answer 19

higher than normal pressure readings

Question 20

what happens when refrigerant escapes or is released into the atmosphere

Answer 20

its temperature drops instantly . and can cause frostbite

Question 21

what is the only way to measure how much refrigerant is in an air conditioning system

Answer 21

remove all of the systems refrigerant and charge and weigh it

Question 22

why must you never use shop air when pressure testing the air conditioning system

Answer 22

because R - 134a and oxygen in compressed air form a combustible mixture

Question 23

when checking for a refrigerant leak by watching the gauge readings

Answer 23

if they drop as little as 1 psi over five minutes the air conditioning system has a leak and must be repaired

Question 24

when using nitrogen to check for leaks never exceed

Answer 24

250 psi low pressure lines may rupture

Question 25

all three shut off valves on a gauge set must have

Answer 25

a shut off valve within 10 inches of the ends

Question 26

how often should a truck HVAC system be inspected

Answer 26

every six months

Question 27

a correctly operating thermostat should start to open

Answer 27

2 - 5 degrees below its rated temperature

Question 28

what would an overcharge of refrigerant cause

Answer 28

both pressure readings to be high

Question 29

what is compressor slugging

Answer 29

when the compressor fills with liquid refrigerant due to failing compressor components

Question 30

when doing a visual inspection of a temperature sensing bulb it must be

Answer 30

securely attached and insulated to the evaporator outlet sensing line