HVAC

Question 1

What do you call the line that traps moisture and dirt in the gas line (natural gas line)?

Answer 1

Drip leg

Question 2

What air is used for ignition? furnace.

Answer 2

Primary air

Question 3

What air is used to support the primary air?

Answer 3

Second air

Question 4

What kind of pressure that the induced motor maintain?

Answer 4

Negative Pressure

Question 5

A flame that is bright blue inner surrounded lighter blue outer is known as?

Answer 5

No unburned carbons

Question 6

A typical furnace is equipped with a burner, a combustion blower to move combustion gas. True or False?

Answer 6

True

Question 7

What tool do you use to check and set the gas pressure?

Answer 7

manometer

Question 8

If the flam tip is yellow, what does that mean?

Answer 8

insufficient primary air

Question 9

What is the by-product of incomplete combustion? If not burning properly.

Answer 9

Carbon monoxide

Question 10

A high-efficiency condensing furnace uses PVC Vent piping. What category?

Answer 10

category 4

Question 11

What is the purpose of the thermocouple?

Answer 11

To maintain the pilot light for safety.

Question 12

What is the purpose of the flame sensor?

Answer 12

Senor the flame

Question 13

What current does the thermocouple produce when heated?

Answer 13

DC

Question 14

Is it safe that a standing pilot or hot surface ignitor are used for ignition source on a furnace. T or F?

Answer 14

True.

Question 15

Can a technician jump a limit switch?

Answer 15

Yes. the purpose of testing only.

Question 16

The combustion blower/ induced draft is designed to bring in combustion air. The indoor blower is designed to push conditioned air. True or False?

Answer 16

True

Question 17

What is one of the main causes of the flame sensor failure?

Answer 17

Dirty or corroded

Question 18

What are the 6 steps of the firing sequence of the furnace?

Answer 18

1) Inducer motor/combustion blower
2) Pressure Switch
3) Ignitor
4) Gas valve
5) flame sensor
6) indoor blower

Question 19

What is the proper gas setting for natural gas?

Answer 19

3.5 inches of WC (water column).

Question 20

What is the proper gas setting for propane?

Answer 20

10.5 inches of WC (water column).

Question 21

Will the ignitor stay energized for relighting if the flame sensor does not protect the flame?

Answer 21

No. no relighting. has to start over the sequence.

Question 22

What category is 80% non-condensing mini-efficiency furnace that uses V vent pipe?

Answer 22

category 1. 4 is for high efficiency

Question 23

T or F. when a technician is brazing his line set, should he run nitrogen through it?

Answer 23

True

Question 24

We should always calibrate our gauges to what on our manifolds?

Answer 24

Zero atmospheric pressure 14.7psi

Question 25

Should a technician always have a fire extinguisher at the job site when brazing?

Answer 25

Yes

Question 26

Can you release 410A into the atmosphere over R22?

Answer 26

No. It is illegal. can't release any refrigerant into the atmosphere.

Question 27

By using methods by charging by superheat and subcool protect the compressor?

Answer 27

yes.

Question 28

What kind of acid for we produce we combine refrigerant, oil, and heat?

Answer 28

Hydrofluoric and Hydrochloric

Question 29

If you get to a system and you put your manifolds on and it reads zero PSIg what does that mean?

Answer 29

Means it is empty. Can not recover anything.

Question 30

Is Nitrogen safe to release to the atmosphere?

Answer 30

yes

Question 31

Do you need a regulator when you are dealing with any gas?

Answer 31

Yes

Question 32

What is the one thing we always install in our liquid line? new or repairing a system

Answer 32

liquid line dryer

Question 33

If the fan motor fails to operate. Will that increases or decrease the head pressure?

Answer 33

Increase

Question 34

What do we use to measure Ohms with?

Answer 34

Ohm's meter

Question 35

whenever we recover refrigerant to a bottle (yellow and gray). What percentage do we go?

Answer 35

80% of the bottles W.C. (water capacity)

Question 36

What do we use a vacuum pump for?

Answer 36

Vacuum the compressor

Question 37

What do you use a recovery for?

Answer 37

To recover refrigerant

Question 38

What do you use to cut tubing with?

Answer 38

Tubing Cutter. circular saw

Question 39

Sometimes you have to cut the side out of the furnace for up flow. How do you cut it out?

Answer 39

Take a skilled saw and flip the blade backward

Question 40

What is the purpose of a high-pressure switch?

Answer 40

Protect high-pressure.

Question 41

The center port of the manifold is used to do what?

Answer 41

charging, recovering, evacuating

Question 42

What kind of gauge is used

Answer 42

compound gauge

Question 43

Once the compressor is pulled down to its proper vacuum what do you do next?

Answer 43

valve off your manifolds

Question 44

What is a proper vacuum level

Answer 44

500 microns or less

Question 45

How do you adjust superheat?

Answer 45

By adding or removing refrigerant.

Question 46

Can you retrofit 410A to R22 by changing the metering device?

Answer 46

False