Electrical troubleshooting and maintenance

NAVEDTRA 14057 Ch. 13 — Electrical Damage

Explanation Example Electrical Power Lost Electrical Power Ordered Isolated Electrical Power Isolated Electrical Power Restored EXAMPLE-Final Triangle for DC Plates NAED ED ED ED NAED ED ED ED No Apparent Electrical Damage Electrical Damage Reported Electrical Damage Under Repair Electrical Damage Repaired EXAMPLE-Final Triangle for DC Plates DCfAIV09

NAVEDTRA 14075 Ch. 6 — Test Remedytrouble Possible

CAUSE Relocate thermostat to a place more representative of average space temperature. Space temperature higher than thermostat setting and thermostat contacts are open. B a d l o c a t i o n o f thermostat. Carefully read temperature at the sensing element. Thermostat out of ad- Calibrate with good C l e a n , a d j u s t , o r justment or sticking. thermometer. replace the thermostat. Cooling coil magnetic valve not opening. Solenoid Valve. Valve sticking. Replace solenoid coil. Clean valve or adjust pilots. Space temperature thermostat lower than thermostat setting and contacts are closed. Bad location of thermostat (this will also effect cooling). Test with reliable ther- Move thermostat to a mometer at location. better location. Space temperature lower than thermostat setting and ther…

NEETS Module 16 §1.5

INTRODUCTION TO TROUBLESHOOTING Our military forces increasingly rely on electrical and electronic equipment to help perform their mission. The effectiveness of our tactical forces depends on many types of electronic systems, such as communications systems, detection systems, and fire control systems. The reliability of such equipment is determined by many factors; however, the primary factors are the quality of the equipment in use, the availability of spare parts, and the ability of maintenance personnel to perform adequate maintenance. Maintenance is work done to correct, reduce, or counteract wear, failure, and damage to equipment. Maintenance of electrical and electronic equipment is divided into two main categories: PREVENTIVE (routine) and CORRECTIVE maintenance. Preventive mainten…

NEETS Module 16 §1.5.5

Working on De-Energized Circuits When any electronic equipment is to be repaired or overhauled, certain general safety precautions should be observed. They are as follows: • Remember that electrical and electronic circuits often have more than one source of power. Take time to study the schematics or wiring diagrams of the entire system to ensure that all sources of power have been disconnected • If pertinent, inform the remote station regarding the circuit on which work will be performed. • Use one hand when turning switches on or off. • Safety devices, such as interlocks, overload relays, and fuses, should never be altered or disconnected except for replacement. In addition, they should never be changed or modified in any way without specific authorization. • Fuses should be removed and…

NEETS Module 16 §1.6.1

Voltage and Current Measurements Voltage measurements may be made as part of either preventive or corrective maintenance. These measurements are made using a voltmeter. When compared with voltage charts, these measurements are a valuable aid in locating a trouble quickly and easily. However, if the sensitivity of the test voltmeter differs from that of the voltmeter used in preparing the chart, the voltage measurements must be evaluated before the true circuit conditions can be determined. (Sensitivity in voltmeters was discussed in NEETS, Module 3, Introduction to Circuit Protection, Control, and Measurement.) Since many of the troubles you find in equipments and systems are the result of abnormal voltages, voltage measurements are a valuable aid in locating trouble. You can measure volt…

NEETS Module 16 §6.6 ¶2

SUMMARY A-4 TEST EQUIPMENT INDEX - The Navy guide used to assist in identifying portable electrical/electronic test equipment required for support of prime electrical/electronic, IC, weapons, and reactor instrumentation systems. TEST POINTS - Locations in equipment that are accessible to the technician's probes where operating voltages or signals can be monitored. THERMISTOR - A type of bolometer characterized by a decrease in resistance as the dissipated power increases. TROUBLESHOOTING - A procedure used to evaluate equipment performance and repair equipment when it fails to operate properly. TUNED CIRCUIT - A circuit that is used as a filter which passes or rejects specific frequencies. VOLTMETER - A meter that is used to measure voltage. WATT - The unit of electrical power that is the…