System Diagnostics and Troubleshooting Procedures

by Tomczyk, John

• ISBN13: 9781930044159
• ISBN10: 1930044151
• Format: Spiral Bound
• Copyright: 2003-01-01
• Publisher: Esco Institute

Table of Contents

Diagnosing Air Conditioning Systems
Air Flow	1	(2)
Refrigerant Cycle	3	(6)
Condensers	3	(1)
Liquid Line Restrictions	4	(1)
Suction Line Restrictions	4	(1)
Undercharge	5	(1)
Overcharge	5	(1)
Compressor Inefficiencies	5	(1)
Noncondensibles	6	(1)
Low Condenser Air Entering Temperature	6	(1)
High Condenser Air Entering Temperature	7	(1)
Capillary Tubes	7	(1)
TXVs	7	(2)
Systematic Troubleshooting
Service Checklist	9	(1)
Troubleshooting	9	(23)
Undercharge of Refrigerant	10	(2)
Compressor discharge	10	(1)
High evaporator superheat	11	(1)
High compressor superheat	11	(1)
Low condenser subcooling	11	(1)
Low compressor amps	11	(1)
Low evaporator pressure	11	(1)
Low condensing pressure/temperature	11	(1)
Overcharge of Refrigent	12	(1)
High discharge temperature	13	(1)
High condenser subcooling	13	(1)
High condensing pressures	13	(1)
Higher condenser splits	13	(1)
Normal to high evaporator pressures	13	(1)
Normal evaporator superheat	13	(1)
High compression ratios	13	(1)
Overcharged Capillary Tube Systems	13	(1)
Dirty Condenser or Restricted Air Flow Over Condenser	14	(1)
High discharge temperatures	14	(1)
High condensing pressures	14	(1)
High condenser splits	15	(1)
Normal to high condenser subcooling	15	(1)
Normal to high evaporator pressures	15	(1)
Normal superheat	15	(1)
High Compression Ratios	15	(1)
High amp draw	15	(1)
Restricted Liquid Line After the Receiver	15	(4)
Higher than normal discharge	16	(1)
High superheat	16	(1)
Low evaporator pressures	16	(1)
Low condensing pressures	16	(1)
Normal condenser subcooling	17	(1)
Low condenser splits	17	(1)
Local cold spot or frost after restriction	17	(1)
Bubbles in sightglass	17	(2)
Low amp draw	19	(1)
Short cycle the low pressure	19	(1)
Restricted Liquid Line Before the Receiver	19	(2)
High discharge temperature	19	(1)
High condensing (head) pressures	20	(1)
High condenser subcooling	20	(1)
High condenser splits	20	(1)
Low evaporator pressures	20	(1)
Low amp draw	20	(1)
Bubbling sightglass	20	(1)
Short cycling on the LPC	20	(1)
Air in the System	21	(1)
High discharge temperatures	21	(1)
High condensing (head) pressures	22	(1)
High condenser subcooling	22	(1)
High condenser split	22	(1)
High compression ratios	22	(1)
Normal to slightly high evaporator (suction) pressures	22	(1)
Normal superheat	22	(1)
High amp draws	22	(1)
Restricted Metering Device	22	(2)
High discharge temperatures	23	(1)
Low condensing (head) pressures	23	(1)
Lower condenser splits	24	(1)
Normal to slightly high condenser subcooling	24	(1)
Low evaporator pressure	24	(1)
High superheat	24	(1)
Low amp draw	24	(1)
Short cycling on the low pressure control (LPC)	24	(1)
Restricted Air Flow Over Evaporator	24	(2)
Low discharge temperatures	25	(1)
Low condensing (head) pressures	26	(1)
Low condenser splits	26	(1)
Low to normal evaporator (suction) pressures	26	(1)
Low superheat	26	(1)
Cold compressor crankcase	26	(1)
Oil-Logged Evaporator	26	(2)
Noisy compressor	27	(1)
TXV having a hard time controlling superheat (hunting)	27	(1)
Low evaporator and compressor superheat	28	(1)
Warmer than normal box temperatures with capacity losses	28	(1)
Inefficient Compressor from Bad Valves	28	(4)
Higher than normal discharge temperatures	28	(1)
Low condensing (head) pressures and temperatures	29	(1)
Normal to high condenser subcooling	29	(1)
Normal to high superheat	29	(1)
High evaporator (suction) pressures	29	(1)
Low amp draw	29	(2)
Leak Detection, Evacuation, and Clean-up Procedures	31	(1)
Basic Leak Detection	32	(4)
Testing for Evaporator Leaks	33	(1)
Testing for Condensing Section Leaks	34	(1)
Suction and Liquid Line Leak Test	35	(1)
Advanced Leak Detection	36	(3)
Testing for Pressure Dependent Leaks	37	(1)
Testing for Temperature Dependent Leaks	38	(1)
Testing for Vibration Dependent Leaks	38	(1)
Testing for Combination Dependent Leaks	39	(1)
Testing for Cumulative Microleaks	39	(1)
Modern Leak Detectors	39	(6)
Electronic Leak Detection	39	(1)
Corona discharge	39	(1)
Thermistor	40	(1)
Dielectric	40	(1)
Ion	40	(1)
Electronic Leak Detector Operation	40	(1)
Ultraviolet (UV) Fluorescent Leak Detection	41	(1)
Choosing a UV Lamp	42	(1)
Halide Torch Leak Detection	42	(2)
Refrigerant Dyes	44	(1)
Standing Pressure	44	(1)
Material Safety Data Sheet	45	(2)
Standing Vacuum	47	(1)
Ultrasonic Leak Detection	47	(1)
Leak Pinpointing And Area Monitoring	47	(4)
Sensitivity	48	(1)
Detection Limit	48	(1)
Selectivity	48	(2)
Nonselective detectors	49	(1)
Halogen-selective detectors	49	(1)
Compound-specific detectors	49	(1)
Fluorescent Dyes	50	(1)
Choosing an Area Monitor	50	(1)
System Evacuation Using the Deep Vacuum Method	51	(14)
Why Pull a Vacuum?	51	(3)
Deep Vacuums	54	(1)
Micron Gauges	55	(2)
Vacuum Pump	57	(8)
Single-stage vacuum pumps	57	(2)
Vacuum test manifold with two valves	59	(1)
Vacuum breaker valves	60	(1)
Pressure drop	60	(3)
Vacuum pump oil	63	(1)
Gas ballasts	63	(2)
System Burnout	65	(7)
System Clean-Up	66	(1)
Standard Suction Line Filters	67	(1)
Combination Acid and Moisture Test Kits	67	(5)
Notes	72