1. Transformer inspection:
1) Observe the transformer's oil level: oil-immersed transformer oil play a role in cooling and insulation, the oil level is although the temperature changes, so the transformer is engraved with a different temperature under the corresponding oil level, when the oil level is found to be too low should be measured to compare the transformer's temperature, and carefully observe the transformer body. Whether there is oil leakage phenomenon, if it is a closed transformer should lift the bleeder valve, check whether it is false oil level.
2) Observe the transformer oil color: transformer oil color should be light yellow, transparent without debris, if found in the oil black carbide is should check the tap changer, coil, pile head lead wire, black carbide is generally caused by the arc combustion.
3) Observe the transformer porcelain casing: porcelain casing insulation, casing surface should be clean, no cracks, no damage, no discharge phenomenon.
4) Smell the transformer has no odor
5) Listen to the transformer has no strange sound: the transformer should be normal buzzing sound, if there is a crackling sound, then the transformer has a short-circuit phenomenon.
6) Touch the temperature of the transformer: touch the temperature of the transformer, compared with the past, if there is a rise, you should check whether the current of the transformer is increased, whether the ambient temperature increases, whether the ventilation is smooth, whether the sound is normal. Transformer upper oil temperature can not exceed 85 ℃.
7) There is no debris on the transformer
2. Motor inspection items
1) See if the motor speed is normal, there can not be jamming phenomenon.
2) See if the current and voltage of the motor are over the limit.
3) Look at the motor shell, fan cover, fan whether there is damage, fan cover network is blocked with debris affecting heat dissipation. 4) Look at the motor fastening bolts can not be loose, loose ground angle bolts will cause vibration of the motor.
5) Smell the motor with or without odor
6) Listen to the motor with or without noise, if there is a murmur to find out when the bearing issued by the motor or the internal issued by the internal slight rustling sound is issued by the wind blowing the motor lashing tape thread, generally fine.
7) Feel whether the motor temperature exceeds the standard: motor coil temperature A-95 ℃, E-105 ℃, B-110 ℃, F-125 ℃, H-145 ℃. Rolling bearings can not exceed 95 ℃, sliding bearings can not exceed 80 ℃.
8) Touch the motor vibration can not exceed the standard: 2-pole motor double amplitude value of less than 0.05mm, 4-pole motor double amplitude value of less than 0.08mm, 6-pole motor double amplitude value of less than 0.1mm, 8-pole motor double amplitude value of less than 0.12mm.
9) Before starting the motor should be checked before the motor is surrounded by no one or things, disk motor, listen to the startup sound. Observe the starting current, observe the motor start time (experience: fan start time is about 20S-30S, pump start time is about 10S-20S, other motor start time is about 10S or so)
3. High and low voltage cabinet inspection program
1) the insulators, transformers, Circuit breaker surface should be clean, dry, no damage, no discharge.
2) The oil level of the oil circuit breaker can not be too low or too high, the oil color should be transparent light yellow, no black carbide, no leakage. 3) No debris in the cabinet and the top of the cabinet
4) The temperature of each connector in the cabinet can not exceed 70 ℃
5) No peculiar smell
6) The status of the transfer switch, circuit breaker, and indicator should be corresponded
4. Generator Inspection Items
1) Generator's coil temperature and core temperature can not be exceeded
2) Generator inlet and outlet air temperature can not be exceeded
2) Generator inlet and outlet air temperature can not be exceeded, The outlet air temperature can not be exceeded
3) carbon brush slip ring without spark
4) generator internal discharge, no spark
Usually electrical equipment, often in the sound of the abnormal, color, vibration, smell, temperature and other aspects of the change, inspection should make full use of these changes in the equipment condition to discern.
[1] Visual: electrical equipment abnormalities or faults, often show the agent, paint discoloration, conductor heat, spark increase, discharge flash, leakage of oil or oil color black, paint film peeling and other appearance phenomena. By observing these phenomena, you can make a preliminary judgment on the abnormalities of electrical equipment. Such as transformer leakage, due to poor magnetic conductivity and uneven distribution of magnetic field, the resulting eddy current will cause the oil tank local box overheating caused by paint discoloration, cracking, blistering, peeling, etc.; oil circuit breaker breaks too many times will cause the oil carbonized black; busbar connector heat, the upper part of the hot air can be seen rising, paint discoloration and so on.
[2] Listening: When the electrical equipment is abnormal, it will sometimes emit abnormal sound. Through careful listening (sometimes with the aid of a listening stick and other tools), you can find equipment problems. Such as transformer sound than usual increase, may be transformer overload or system overvoltage (such as neutral point not grounded system occurs when single-phase grounding or ferromagnetic *** vibration); such as sound mixed with "squeak" discharge sound, it may be the transformer body or casing and other surfaces of the partial discharge; such as motor found to have anomalous noise, then May be the motor dynamic and static part of the friction, out of phase operation, bearing oil or core loose.
[3] Nose: Electrical equipment flashover, short circuit, overload, overvoltage, often due to breakdown of the insulation medium burned and produce an abnormal odor. Therefore, through the nose to the odor of the defense, you can also find equipment abnormalities. Such as motor internal short circuit or wire short circuit, etc., will produce a strong insulation burning odor, porcelain casing dirty flash discharge will produce an odor.
[4] hand touch: electrical equipment abnormal or faulty, often accompanied by heat and vibration and other phenomena, so the motor casing, bearing housing and other parts of a good grounding (confirm the presence of non-sensory parts) can also be perceived by hand. In general, the motor overload shell will be very hot, if the hand is hot and immediately retracted, the motor may be overheating, need to further verify the measures taken such as motor bearing bullet damage, the center is not correct, etc., will make the motor vibration increase, bearing hot, with a hand touch can be quickly concluded.
4 Make full use of the bad weather inspection of electrical equipment
Many operators often relax the bad weather or night inspection work missed the discovery of defects and abnormalities in the equipment to confirm a good opportunity. Such as rain and snow days, according to the raindrops, snowflakes, analyze and judge whether the bus, wire clevis contact is poor and heat, night can be through the transformer casing corona glow or orchid small sparks, it is easy to judge whether the transformer casing is dirty flash and so on