Atkins Physical Chemistry
10th EditionJulio de Paula, Peter Atkins
1,315 solutions
Atkins Physical Chemistry
10th EditionJulio de Paula, Peter Atkins
1,315 solutions
양자화학
2nd EditionDonald A. McQuarrie
285 solutions
Chimica Fisica: Un Approccio Molecolare
1st EditionDonald Allan McQuarrie, John D. Simon
139 solutions
Recommended textbook solutions
Introduction to Chemical Engineering Thermodynamics
7th EditionHendrick Van Ness, J.M. Smith, Michael Abbott
582 solutions
Chemistry for Engineering Students
2nd EditionLawrence S. Brown, Thomas A. Holme
945 solutions
Advanced Engineering Mathematics
10th EditionErwin Kreyszig
4,134 solutions
Engineering Circuit Analysis
9th EditionJack E. Kemmerly, Steven M. Durbin, William H. Hayt
785 solutions
A burnout is a condition in which the insulation of an electric motor deteriorates due to over heating.
A restricted condenser, a large heat load on the evaporator, or a high-side restriction may all result in a high-pressure cut-out and motor overheating. In time, the condition could lead to burnout and and a motor winding short. The breakdown of motor windings causes contamination or burning or the refrigerant oil. Such oil becomes acidic.
To prevent acid formation, a refrigeration system must be kept free of moisture and contaminants. Condensers should be regularly cleaned and checked for obstruction-free airways to prevent high head pressure.
Home
Subjects
Expert solutions
Create
Log in
Sign up
Upgrade to remove ads
Only ₹2,287/year
-
Flashcards
-
Learn
-
Test
-
Match
-
Flashcards
-
Learn
-
Test
-
Match
Terms in this set (34)
When replacing and old polychlorinated Biphenyl Dielectric ( PCB ) capacitor the old capacitor must be disposed of _______
1. with common trash in the dumpster
2. Dispose of by burning
3. Return for deposit
4. Dispose based on local environmental laws
Answer 4
MRAC page 403 20th edition ???
In absorption refrigeration systems lithium bromide is used as the refrigerant. What is the maximum percentage by weight of lithium bromide before crystallization will begin at temperatures below 110 F
1. 35 %
2. 45 %
3. 55 %
4. 65 %
Answer 4
Page 890, 21st edition
What is the purpose of the external equalizer in a thermostatic expansion valve ?
1. Compensates for pressure drop in the evaporator
2. Keeps the valve from hunting when full load conditions are present.
3. Stops slugging during light load conditions
4. Makes superheat adjustment more accurate
Answer 1 page 479 , 21th edition
What is the proper way to size a liquid receiver for a commercial refrigeration or air conditioning system?
1. Sized to hold 50%
of the refrigerant charge
2. sized to hold 75 % of the refrigerant charge
3. Size to hold 115 % of the refrigerant charge
4. Sized to hold 125 % of the refrigerant charge
Answer 3 page 1347, 21st edition
The highest Temp at which substance may be liquefied, regardless of pressure applied upon it called ____ ?
1. Enthalpy
2. Entropy
3. Critical pressure
4. Critical temperature
Answer 4 page 73, 21st edition
32 F is equal to ____ Rankin degrees ?
1. 32 degrees
2. 0 degrees
3. 273 degrees
4. 492 degrees
Answer 4 page 59, 21st edition
A 12 psig pneumatic control system has an operating pressure range of ___ PSIG to ____ psig ?
1. 0 - 12 psig
2. 3 - 15 psig
3. 5 - 17 psig
4. 7 - 15
psig
Answer 2 page 840, 21st edition
What is the refrigerant code number for nitrogen ?
1. R - 407C
2. R - 770
3. R - 744
4. R- 728
Answer 4 page 178 21st edition
Wat is the most rapid method of adding refrigerant to a semi- hermetic compressor ?
1. Valve off compressor and add oil with a refrigerant oil
pump
2. Remove the suction service valve and pour in oil
3. Draw a slight vacuum on the crankcase by closing suction service valve and draw through with a hose or tube.
4. Oil should never be added to a compressor.
Answer 3 page 1466, 21st edition
What is the allowable pressure drop across a suction line filter drier when used for air conditioning duty ?
1. 6 psi
2. 8 psi
3. 10 psi
4. Minimal
Answer 4 page 550, 21st edition
What is the minimum test pressure for refrigerant pipe installations when using air - cooled equipment and R -410A refrigerant ?
1. 169 psig
2. 278 psig
3. 449 psig
4. 302 psig
Answer 3 Page 1375, 21th edition
When fuel oil is subjected to excess vacuum it begins to ______
1. thicken
2. lose viscosity
3. foam
4. explode
Answer 3 page 1134, 21st edition
What is a typical application of the vortex tube cooling principals ?
1. Aircraft cooling
2. Industrial process cooling
3. Welding operations
4. Protective suits
Answer 4 page 1287, 21st edition
The cooling of a liquid refrigerant below its condensing temperature.
1. Sublimation
2. Subcooled
3. Subtricate
4. Isotropic
Answer 2 page 66 21st edition
A three - phase air handler motor is running backwards, how is the rotation changed ?
1. Reversing the high voltage and low voltage # 2 taps
2. Changing any two phase conductor leads
3. Must change the motor
4. Spin the motor 180
degrees in the mount
Answer 2 page 325, 21st edition
When installing a thermostatic expansion valve sensing bulb on a vertical suction line, The bulb should be mounted so the capillary tube entering the sensing bulb is ______ ?
1. At the top
2. at the bottom
3. It does not matter
4. Never mouton a vertical suction line
Answer 1 page 483, 21st edition
A temperature of 40 C is equal to ___ F ?
1. 40 F
2. 52 F
3. 62 F
4. 104F
Answer 4 page 59, 21st edition
The term " Dirty sock syndrome " refers to ?
1. Mold odors in bathroom ducts
2. Odors associated with water carryover from heat pump coils
3. An odor that occurs in the heat pump during the heating and defrost cycle .
4. A
condition found when homes are left vacant for long periords
Answer 3 page, 1075 21st edition
_________ is used primarily in square and rectangular ducts to restrict or completely shut-off the flow of air to a room or zone ?
1. Volume damper
2. Manual damper
3. Multi Blade Damper
4. Splitter damper
Answer 3 page 739, 21st edition
How many BTU of heat energy is required to melt 2000 pounds of ice in a 24 - hour period ?
1. 12,000 btu
2. 36,000 btu
3. 125,000 btu
4. 288,000 btu
Answer 4 page 66, 21st edition
Many room air conditioners use ________ compressors.
1. Rotary compressors
2. Permanent split - Capacitor motors
3. Scroll compressors
4. Capacitor - start capacitor- run
compressors
Answer 2 page 786, 21st
When internally insulating metal rectangular duct, how much glue coverage is recommended on the metal duct before the insulation is applied.
1. 50 % coverage
2. Glue manufactures directions
3. Insulation manufactures directions
4. 100 % coverage
Answer 3 page 735, 21st edition
Line voltage thermostats may control loads up to ___ amps.
1. 10 amps
2. 18 amps
3. 20 amps
4. 22 amps
Answer 4 page 923, 21st edition
A systems control differential is the difference between _____________.
1. Heat in and heat out
2. Cut- out and cut in
3. Balance point
4. Controlled variable and setpoint
Answer 2 Page 339, 21st edition
What is the difference between brazing and soldering .
1. Filler metal is harder
2. Filler metal is softer
3. Soldering is for plumbing pipe joints
4. Filler material melting point
Answer 4 page 146, 21st edition
What is the purpose of flux.
1. To keep pipe and tube joints clean
2. prevents oxidation
3. Assures adhesion
4.
Used only for plumbing fitting and pipe
Answer 2 page 146, 21st edition
How many cubic feet of volume does one pound of standard are occupy ?
1. 5.05 cubic feet
2. 13.454 cubic feet
3. 16.99 cubic feet
4. 1.0 cubic foot
Answer 2 page 55, 21st edition
The _____ point is where wax separates from refrigerant oil.
1. wax point test
2. Separation point
3. Floc point
4. Pour point
Answer 3 page 179, 21st edition
________ is the instantaneous evaporation of liquid refrigerant that cools the remaining refrigerant to the desired evaporator temperature.
1. Flash gas
2. Superheat
3. sub cooling
4. Evaporation
Answer 1 page 91, 21st edition
A refrigerant designed to replace R - 22 that consists of 23 %, R-22, 25 %, R -32, 25 %, R 125 and 52 % R-132 a
1. R-410 A
2. R 407c
3. R -507 C
4. R - 404 a
Answer 2 page 174, 21st edition
When installing vibration isolators, there location should be _______ ?
1. Within 8 inches of the compressor
2. within 12 inches of the compressor
3. anywhere
near the compressor
4. as close as possible to the compressor
Answer 4 page 462, 21st edition
A ______ delivers a concentrated airstream into a room ?
1. Grill
2. diffuser
3. Register
4. Supply outlet
Answer 3 page 738, 21st edition
to control vibration when compressors with spring isolators are use, the isolators should be ______ ?
1. kept fully seated
2. The bolts completely removed
3. the bolts backed out to provide clearance
4. Rubber pads shall be installed under the unit
Answer 3 Page 1364, 21st edition
When brazing refrigerant lines to equipment, what precautions should be taken ?
1. keep a fire extinguisher readily accessible
2. use a Brazing shield
3. use a wet quenching
cloth
4. use heat absorbing paste
Answer 2 page 1365, 21st edition
Sets with similar terms목요일 5과
45 terms
quizlette2297126
777 - Navigation
56 terms
danielatwell
Physical Training
20 terms
Cleoj607
B777 - Communication - Updated
27 terms
krayw
Sets found in the same folderTechnical exam 1 Hvac
46 terms
Juan_Alvarado24
Technical test 2 HVAC
53 terms
Juan_Alvarado24
Technical test 3
45 terms
Juan_Alvarado24
Laws and Rules Questions
10 terms
Juan_Alvarado24
Other sets by this creatorSC HVAC EXAM
24 terms
Juan_Alvarado24
section 17 - residential/light commercial based on…
98 terms
Juan_Alvarado24
business test II
50 terms
Juan_Alvarado24
Business Test 1
50 terms
Juan_Alvarado24
Other Quizlet setsChapter 11, 12, 13: Middle Childhood
24 terms
bethany_dahl5PLUS
Ch 2 - Atoms, Bonds, Acids, Base, Molecu…
36 terms
ariel_endsley
PSYC 2050 Midterm
159 terms
ostermac
Permit Test
27 terms
eddie_cundiff