Deck 10: System Charging

Question 1

If 22 oz. of refrigerant are to be added to a refrigeration system and the supply cylinder weighs 24 lb. 12 oz. before any is added, what will be the supply cylinder weight after the system has been charged?

A) 23 lb 12 oz.
B) 22 lb 12 oz.
C) 22 lb 6 oz.
D) 23 lb 6 oz.

Answer 1

D

Question 2

One good feature of an electronic charging scale is that it counts upward as refrigerant is removed, to tell the technician how much refrigerant was used.

Answer 2

True

Question 3

If the tank is a reusable tank, there are no check valves and system refrigerant can enter the tank as long as the system pressure is higher than the pressure in the tank.

Answer 3

True

Question 4

The factory charge in a split system, using R-22, shows 6 lb. 8 oz. in the outdoor condensing unit and 2 oz. in the evaporator. The 3/8" liquid line contains 0.48 oz. per foot and the 7/8" suction line contains 0.10 oz. per foot. The refrigerant lines are 30' long. What is the correct refrigerant charge for this system?

A) 6 lb 10 oz.
B) 6 lb 15 oz.
C) 7 lb 7 oz.
D) 7 lb 11 oz.

Question 5

The quickest method to charge a system is to charge only vapor.

Question 6

If a critically charged refrigeration system is over charged, which of the following is a likely result?

A) Increased cooling capacity.
B) Reduced compressor discharge temperature.
C) Increased system efficiency.
D) Increased operating pressures.

Question 7

Refrigerant in liquid form is normally put into the system through the ____.

A) liquid line
B) suction line
C) hot gas line
D) liquid return line

Question 8

Using a restrictor, liquid refrigerant can be charged into the low-side of the system with the system operating.

Question 9

When charging liquid refrigerant from a single valve supply cylinder, the cylinder is placed ____.

A) upside down
B) right side up
C) on its side
D) in any position indicated

Question 10

A graduated cylinder charging device is a device that ____.

A) measures refrigerant by volume for precise refrigerant charging
B) has a compensation dial for adjusting for the temperature of the refrigerant
C) often has a heater to keep the refrigerant temperature from dropping when refrigerant is released into the system
D) All of the above.

Question 11

When the system pressures are lower than the pressure in the refrigerant tank, such as when the system has just been evacuated or if the system is out of refrigerant, refrigerant can be added to both the high and low pressure sides of the system.

Question 12

When adding refrigerant in liquid form into the high-side of the system, the system motor/compressor assembly is running.

Question 13

When adding refrigerant in vapor form to an operating refrigeration system, the refrigerant must be added to the low-pressure side of the system .

Question 14

A manufacturer's charging chart may be used when available to determine the correct charge for a system.

Question 15

Fractionation occurs when ____.

A) some of a blended refrigerant evaporates or condenses before the rest of the blend
B) when only a fraction of the total charge has been added to a system
C) the operating pressures of a system increase
D) Both a and c.

Question 16

When charging a system with vapor refrigerant from a refrigerant cylinder, the cylinder will become ____.

A) cold
B) very warm
C) the same temperature as the ambient air
D) very cold

Question 17

If 30 oz. of refrigerant are to be added to a refrigeration system and the supply cylinder weighs 26 lb. 4 oz. before any is added, what will the supply cylinder weigh after the system has been charged?

A) 22 lb 8 oz.
B) 24 lb 6 oz.
C) 24 lb 8 oz.
D) 22 lb 4 oz.

Question 18

Refrigerant in vapor form is normally put into the system through the ____.

A) liquid line
B) suction line
C) hot gas line
D) liquid return line

Question 19

Charging a refrigeration system refers to ____.

A) removing refrigerant from a system
B) adding refrigerant to a system
C) cleaning the refrigerant
D) vaporizing the refrigerant

Question 20

When charging a refrigeration system with a near-azeotropic mixture, what must be done to prevent liquid from entering the system?

A) Charge only as a vapor through the high side.
B) Charge only liquid through the high side.
C) Charge as a liquid through the low side using a restrictor.
D) Charge as a vapor through the low side using a resistor.

Question 21

The charging device that holds refrigerant, has a visible column of liquid, and can be used to "visually" see the amount of refrigerant used is called the ____________________.

Question 22

If the pressure in the refrigerant cylinder drops down too low to charge a system (cylinder pressure = low side system pressure), how can the technician increase the cylinder pressure?

Question 23

Refrigerant in vapor form is added to an operating system through the ____________________ side of the system.

Question 24

When the warm refrigerant cylinder is connected to an operating system, the pressure in the cylinder will be ____________________ than the suction pressure of the system.

Question 25

As refrigerant vapor is removed from a supply cylinder, the pressure in the supply cylinder will ____________________.

Question 26

The ____________________ is used to help technicians perform a number of tasks including taking pressure readings on the high side of the system and trapping all of the system refrigerant in the receiver to perform system service.

Question 27

Glide is the range of temperatures/pressures in which a blended refrigerant will condense.