Notes

Question 1

If an oil pressure control should open due to lack of oil pressure, the voltage reading across the L and M terminals would read, if the supplied control voltage were 240v

a) 240v
b) 120v
c) 0v
d) 24v

Answer 1

a)

Question 1

During evacuation, when should the gas ballast on a vacuum pump be closed?

a) only be open during venting of pressure from system
b) closed as soon as vacuum starts to pull
c) has no effect on operation
d) closed near the end of the vacuum process

Answer 1

d)

Question 2

How to check if your level is level?

Answer 2

Use high point of floor

Question 3

Open the gas ballast on your vacuum pump until the system reaches?

Answer 3

1000-3000 microns

Question 4

What do you do to your vacuum pump when you go on vacation?

Answer 4

change oil and top it up higher than regular

Question 5

Which is thicker?

valve plate gasket or cylinder head gasket?

Answer 5

valve plate gasket

Question 6

What is the way to clean up the water lines in a shell and coil water cooled condenser?

Answer 6

chemicals only

Question 7

Start sequence for a water cooled condenser AC unit?

Answer 7

Fan, water pump, compressor

Question 8

How to cut capillary tube?

Answer 8

use a file and bend to break tube do not damage inside diameter

Question 9

Name the four types of distribution duct systems

Answer 9

Radial
Extended plenum
Reducing trunk
Perimeter loop

Question 10

Name 5 types of nonmetal ducts

Answer 10

fiberglass
urethane
plastic
sheetrock
textile

Question 11

True or False? It is illegal to put screws in duct work

Answer 11

True

Question 12

What is the R value used to describe?

Answer 12

rate the thermal resistance of insulation materials

Question 13

The higher the R value, the ________ it is for heat to pass through the material

Answer 13

higher

Question 14

If walls are made up of different materials, how is the R value calculated?

Answer 14

Each material’s R value is added to create a total R

Question 15

The amount of heat that will pass through 1ftsq of material 1’’ thick in 1 hour when the temperature difference is 1F is known as ?

Answer 15

Thermal conductivity (K value)

Question 16

High __ values indicate high rate of heat transfer

Answer 16

K

Question 17

Amount of heat that will pass through 1ftsq of material that is NOT 1’’ thick in 1 hour when the temperature difference is 1F is known as?

Answer 17

C value

Question 18

What is the difference between C and K values

Answer 18

K value is based on material that IS 1’’ thick.

C value is based on material that is NOT 1’’ thick

Question 19

How to determine thermal conductance?

Answer 19

Find on chart and divide K value of each material by its thickness

Question 20

When the compressor has adequate oil pressure the contacts between L and M are

a) open
b) closed
c) closed then open
d) open then closed

Answer 20

B

Question 21

A term used to rate vacuum pumps is used to describe the pumps ability to draw a vacuum. Pump must create a vacuum within itself that is lower than a system, so that gases will flow from system to the pump. Point at which the pump can no longer create a pressure difference is the

a) dead head pressure
b) blank off pressure
c) blocked tight static pressure
d) point of no pressure difference

Answer 21

b

Question 22

An imperial gallon of water weighs

a) 8.33lb
b) 10lb
c) 62.4lb
d) 64.2lb

Answer 22

b

Question 23

Superheat is bad and only for mainly protecting?

Answer 23

compressor

Question 24

Low ambient conditions lower head pressure which means less push of liquid into which component?

Answer 24

metering device

Question 25

1deg of subcooling gives ___ more liquid and more cooling.

Answer 25

0.5

Question 26

What is the liquid to vapour ratio in evap?

Answer 26

75 liquid to 25 vapour

Question 27

Which type of oil is most hygroscopic?

A) POE
b) Mineral

Answer 27

A