Accessories Ppt notes page 3+4

Question 1

Crankcase heaters: Purpose;

1. Prevents off cycle _______ of refrigerant by warming the oil in the crankcase
2. Prevents liquid _______ of refrigerant oil (flooded starts)

Answer 1

1. prevents off cycle migration

2. prevents liquid dilution

Question 2

Crankcase Heaters: Types;

1. Electrical (75watt)
   - Internal: insertion in a ___
   - External: Wrap _____
2. Coil _______
3. Oil ________

Answer 2

1. Electrical 75watt, Internal is insertion in a well and external is wrap around
2. coil discharge
3. oil separator

Question 3

Crankcase Heater: Purpose;

1. Minimizes the amount of ____ circulated through the system
2. excessive oil circulation causes reduced system ______ by reducing heat transfer within the evap coil
3. Especially important if the oil is not ______ with the refrigerant such as R-717 or R22 in low temp applications

Answer 3

1. oil
2. capacity
3. miscible

Question 4

Crankcase Heaters: Installation;

1. _______ line of the system
2. Return line back to ______ (with shut off valve)
3. separator should be

Answer 4

1. discharge line of the system
2. return line back to crankcase
3. separator should be insulated

Question 5

Liquid Line Heat Exchanger: Purpose;

1. Increase suction line ______ and increase liquid line ________
2. Make sure they have a bit of superheat to protect the _________
3. May help provide minimum _______ requirement
4. Tube within a tube: vapour in suction line is ______ than liquid in liquid line

Answer 5

1. increase suction line superheat and increase liquid line sub-cooling
2. compressor
3. superheat
4. colder

Question 6

Evaporator Pressure Regulator: (EPR)

Also known as;

1. Pressure reducer _____
2. Two ________ ______
3. ______ pressure valve

Answer 6

1. pressure reducer valve
2. two temperature valve
3. constant pressure valve

Question 7

Evaporator Pressure Regulator:

1. Location: At the ______ of the evaporator
2. Valve operation: maintain pressure which means it opens on _____ of _____
3. When inlet valve pressure is higher than spring it will ______ refrigerant to go through the valve
4. Open force is _____ and closing force is the _____

Answer 7

1. outlet
2. rise of inlet
3. allow
4. suction, spring

Question 8

Evaporator Pressure Regulator: Purpose;

1. To prevent evaporator from going below a predetermined _____ or ________
2. Types: (2) _____ operated and _____ operated

Answer 8

pressure or temperature

temp operated and press operated

Question 9

Evaporator Pressure Regulator: Applications;

1. Any application where an abnormally ____ temp could create a problem
2. On a system operating two or more condition spaces at _______ temps
3. On ______ systems one setting used for operating cycle and other setting used during ______ mode
4. Multiple Evap/Temp systems EPR is installed at the _____ of the warmest coil

Answer 9

1. low
2. different
3. ammonia, defrost mode
4. outlet

Question 10

Evaporator Pressure Regulator: Applications;

5. *Check valve must be located at the _____ of the ______ coil
6. Required if TD between warmest and coldest coils exceed __F
7. Controlled evaporators must not exceed ___% of grand total load

Answer 10

5. outlet of the coldest coil
6. 5F
7. 40%

Question 11

EPR Considerations;

1. At 40% EPR load, system may require capacity control using a _______ bypass valve to compressor suction, along with a de-superheating _______ valve
2. A ____ tank may also be required to prevent _____ cycling

Answer 11

1. discharge bypass valve, along with a de superheating expansion valve
2. surge tank, to prevent short cycling

Question 12

Check Valve: Types;

3. _____ gate

Answer 12

1. ball
2. magnetic
3. swing gate

Question 13

Muffler: Purpose;

1. To ______ gas pulsation which helps reduce _______ transmitted to refrigerant lines

Answer 13

1. reduce gas pulsation to help reduce vibrations

2. reciprocating

Question 14

Muffler: Installation;

1. Mounted ________ or ________
2. horz install must ensure bulge is on ___ to prevent oil trapping
3. when brazing heat rapidly and direct flame away from ______
4. Must be ________
5. protect from _________
6. Installed with arrow point in direction of ref _____
7. installed _______ from compressor discharge

Answer 14

1. horizontally or vertically
2. top
3. body
4. anchored
5. overheating
6. flow
7. downstream

Question 15

Valves are installed at various locations in the refrigeration system to:

1. isolate equipment for ______
2. _____ portions of the system when refrigerant is not required in a certain area
3. provide manual _____-connection from one component of system to another

Answer 15

1. servicing
2. isolate
3. cross connections

Question 16

Most common valve used?

Answer 16

globe valve

Question 17

Valve used in refrigeration systems with water, brine, and glycol?

Answer 17

gate valve

Question 18

Valve that has very low pressure drop and has flanged connections?

Answer 18

butterfly valve

Question 19

Valves classified by design: Ball Valve;

1. May be used with _______ refrigerants
2. May also be used with ______ refrigerants but are more expensive than gate valves or butterfly valves
3. they have the lowest _______ drop of any valve (when selected full port size in the wide open position)
4. They are best suited to ____ pressure pumped liquid lines

Answer 19

1. primary
2. secondary
3. lowest pressure drop
4. low pressure pumped

Question 20

Valves classified by design: Access Valve;

1. Used to gain access to _____ systems
2. They are equipped with a _______ valve
3. Service lines ______ the schrader valve if equipped with a depressor

Answer 20

1. small
2. schrader
3. depress

Question 21

Valves classified by design: Line Piercing Valve;

1. Used on small systems that do not have ______ valves
2. May be installed on _________ systems
3. Bolt on style tend to ____ as O ring deteriorates over time and exposure to system ___
4. Brazed on ______ valve (on a vapour line)

Answer 21

1. service valves
2. pressurized
3. leak, oil
4. saddle valves

Question 22

Types of connection to piping: Brazed;

1. Used where _______ and _________ is a factor in application
2. Sil-foss is a ______ brazed filler

Answer 22

1. temperature and pressure

2. common brazed filler

Question 23

Types of connection to Piping: Soldered;

1. Used on copper piping where ____ temperatures and pressure is not a factor
2. Not used on ________ refrigerant lines
3. Used for ____ lines

Answer 23

1. high
2. primary
3. drain

Question 24

Valve Stem Packing:

Material must be compatible with _________ and _____ used

Answer 24

refrigerants and oils used