Compressors

Front 1

What's the first thing you do when you enter a compressor room?

Back 1

Be aware of surroundings , listen for unusual sounds. And do a visual safety inspection

Front 2

What are the design temps for air conditioning applications

Back 2

Evaporator 40 degrees and condenser 105 degrees

Front 3

Before a running compressor is disassembled for inspection or overhaul what must you first do?

Back 3

Make sure all parts are available

Front 4

What is the purpose of a piston ring

Back 4

Oil seal. Provide seal between piston and well, Google says sealing the combustion chamber so that there is minimum loss of gases to the crankcase improving heat transfer from the Piston to the cylinder wall

Front 5

Open drive compressors require a shaft seal because?

Back 5

It prevents refrigerant and oil from leaking into the atmosphere

Front 6

Compressors over 15 ton capacity require a internal pressure relief valve this relief valve removes pressure from?

Back 6

Internal pressure relief valve allows hot gas discharge to go back into suction

Front 7

What does excessive pressure and temperature do to a compressor?

Back 7

Possible mechanical failure and other problems in the refrigeration system

Front 8

Lower than normal oil pressure indicates what?

Back 8

Low charge or overcharge or clogged oil separator or oil filter

Front 9

Gear type, vane type, piston type oil pumps are positive displacement pumps for this reason?

Back 9

They need an internal pressure relief valve

Front 10

Capacity control of a multi cylinder compressor verifies its pumping to match what?

Back 10

Matches building load

Front 11

The pressure of the evaporator is controlled by?

Back 11

EPR valve

Front 12

Compressors that reduce capacity by the method of lifting suction valves reduce power input in proportion to the number of inactive cylinders true or false?

Back 12

True

Front 13

Compressors that reduce capacity by Hot Gas bypass will reduce power input in direct proportion to the number of inactive cylinders true or false?

Back 13

False

Front 14

Hermetic compressors require suction gas at a quality and quantity to provide motor and compressor Cooling open drives do not so superheat can be ignored true or false?

Back 14

False

Front 15

Compressors that control capacity by hydraulic cylinder loaders are normally unloaded at startup true or false?

Back 15

True

Front 16

What color is the range spring for an R22 compressor from Trane

Back 16

Green

Front 17

How do you tell the difference between R12 and R22 range Springs on a carrier compressor?

Back 17

By the way it's a wound size and color

Front 18

_________ are used for oil seals on train unloaders?

Back 18

O rings

Front 19

________ prevent excessive oil pressure

Back 19

oil regulators or safety

Front 20

At what test pressure should carrier unloaders operate

Back 20

40 to 50 psi

Front 21

Name four methods of capacity control

Back 21

Hot Gas bypass, suction cut off, slide valve, pre rotational vanes

Front 22

Gas check valves allow gas pressure to equalize compressor suction chamber and compressor crankcase true or false?

Back 22

False

Front 23

What direction should the capacity control stem be turn to load compressor?

Back 23

CCW

Front 24

What should be done to the cylinder wall before installing new piston rings?

Back 24

Hone it

Front 25

Compression ratio is measured using what PSIG or psia?

Back 25

Psia

Front 26

How do you figure out the compression ratio?

Back 26

discharge pressure divided by suction

Front 27

The internal pressure relief valve on a trane compressor is located where?

Back 27

Internally by discharge

Front 28

Carrier oil pump on 5H models operate on either direction?

Back 28

True

Front 29

Oil pressure must be established before cylinders will load? True or false?

Back 29

True

Front 30

When the unit is being reassembled new gaskets should?

Back 30

All of the above

Front 31

Oil failure switches are designed to protect the compressor from oil failure repeatedly resetting them will?

Back 31

Damage the compressor

Front 32

End thrust clearance of the shaft is measured with a siller gauge how do you adjust the clearance?

Back 32

Stack shims to tighten up tolerances

Front 33

When starting a rebuilt compressor be sure to?

Back 33

Check why the previous compressor was damaged.

Front 34

Why do we use torque values

Back 34

To prevent the bolts from breaking

Front 35

Repeated shaft seal failure may be caused by?

Back 35

Overheating or contamination

Front 36

Thrust clearance is measured with what and in what direction?

Back 36

Filler gauge/ forward and backwards

Front 37

Oils fall in three groups animal, vegetable, mineral which is the best for compressors?

Back 37

Mineral

Front 38

Compressor ratios

Back 38

Psig discharge, add atmospheric 14.7

Psig suction, add atmospheric 14.7

Divide

Front 39

What is the purpose of a crankcase heater?

Back 39

To warm up oil and prevent refrigerant migration

Front 40

What actually takes place to cause a compressor to load and unload?

Back 40

The load of the building increases the suction pressure in the evaporator