CLFJR 2014RME, CPM,OSH Preventive maintenance of Electrical equipment ..iieecamarines clfjr 1 This objective of this summit is to up to date systems for preventive maintenance, and to provide logical techniques by which the more common troubles maybe identified and localized. To recommend emergency repairs that will keep the equipment in operation until it can be scheduled out of service. To suggest operating procedures, and to outline inspection programs that will help ensure safe, efficient, economics and dependable operation. To have knowledge on how to test the equipment. To share my knowledge and skills to all electrical practitioner and other professionals Preventive maintenance of Electrical equipment ..iieecamarines clfjr 2 Electrical equipment- any machine powered by electricity Electrical machine - An electrical machine is the apparatus that converts energy in three categories: Generators which convert mechanical energy to electrical energy, Motors which convert electrical energy to mechanical energy, and Transformers which changes the voltage level either High voltage to low voltage or Low voltage to High voltage of an alternating current. (step down/step-up transformer) Preventive maintenance of Electrical equipment ..iieecamarines clfjr 3 Alternating Current Motors Preventive maintenance of Electrical equipment ..iieecamarines clfjr 4 iieecamarines clfjr 5 .AC Motors Preventive maintenance of Electrical equipment .. 16kv – 700hp Preventive maintenance of Electrical equipment ..iieecamarines clfjr 6 .Large Motor – 4. iieecamarines clfjr 7 ..MGES Vacuum pump Preventive maintenance of Electrical equipment . .iieecamarines clfjr 8 .Generators Preventive maintenance of Electrical equipment . iieecamarines clfjr 9 .. Maintenance Planned unplanned Preventive Corrective Breakdown Periodic Predictive Preventive maintenance of Electrical equipment . unplanned • 1.. Breakdown maintenance . Preventive maintenance of Electrical equipment . Such a thing could be used when the equipment failure does not significantly affect the operation or BM production or generate any significant loss other than repair cost.Types of maintenance .iieecamarines clfjr 10 .It means that people/management waits until equipment fails and repair it. Breakdown of switch gear/MCC & transformer Preventive maintenance of Electrical equipment ..iieecamarines clfjr 11 . .Circuit breaker Preventive maintenance of Electrical equipment .iieecamarines clfjr 12 . Just like human life is extended by preventive medicine. It is further PM divided into PERIODIC maintenance and PREDICTIVE maintenance. design to retain the healthy condition of equipment and prevent failure through the prevention of deterioration. oiling and re-tightening ). • 2. Preventive maintenance of Electrical equipment .. the equipment service life can be prolonged by doing preventive maintenance. periodic inspection or equipment condition diagnosis. PREVENTIVE MAINTENANCE (1951 ) - It is a daily maintenance ( cleaning. inspection.iieecamarines clfjr 13 . to measure deterioration. TBM) Time based maintenance consists of periodically inspecting..iieecamarines clfjr 14 . Preventive maintenance of Electrical equipment .Types of maintenance • 2a Periodic maintenance (Time based maintenance . servicing and cleaning equipment and PM replacing parts to prevent sudden failure and process problems. Compared to periodic maintenance. designed to monitor conditions through an on-line system. It manages trend PM values. by measuring and analyzing data about deterioration and employs a surveillance system. in order to use the parts to the limit of their service life. • 2b Predictive maintenance This is a method in which the service life of important part is predicted based on inspection or diagnosis.iieecamarines clfjr 15 . predictive maintenance is condition based maintenance.. Preventive maintenance of Electrical equipment . iieecamarines clfjr 16 . Replacement of parts. Corrective maintenance ( 1957 ) It improves equipment and its components so that preventive maintenance can be carried out reliably. Testing of electrical equipment 3. Calibration of protection relays 4. Equipment with design weakness must be redesigned to improve reliability or improving maintainability CM • OVERHAULING 1. Planned maintenance • 3. 2.. Replacement of new motors (as spare) Preventive maintenance of Electrical equipment . 3phase Preventive maintenance of Electrical equipment .Cooling tower – 200hp.iieecamarines clfjr 17 .. 440v. On line monitoring system Preventive maintenance of Electrical equipment .iieecamarines clfjr 18 .. On line monitoring system Preventive maintenance of Electrical equipment .iieecamarines clfjr 19 .. .Preventive maintenance of EE Preventive maintenance of Electrical equipment .iieecamarines clfjr 20 . How to measure Insulation resistance Preventive maintenance of Electrical equipment .iieecamarines clfjr 21 .. Before the motor is put into operation after a long period of storage.Winding insulation resistance If the motor is not put into operation immediately upon arrival. Preventive maintenance of Electrical equipment . high temperature and impurities in order to avoid damage to the insulation. it is important to protect it against external factors like moisture. you have to measure the winding insulation resistance.. a periodical inspection is necessary. If the motor is kept in a place with high humidity.iieecamarines clfjr 22 . size and type. condition of insulation material used. Preventive maintenance of Electrical equipment . it takes many years of experience to determine whether a motor is ready for operation or not.iieecamarines clfjr 23 . rated voltage. In fact..Winding insulation resistance It is practically impossible to determine rules for the actual minimum insulation resistance value of a motor because resistance varies according to method of construction. some of the terminals carry dangerous voltages and MUST NOT BE TOUCHED..How to measure Insulation resistance Ground insulation test of a motor Safety Tips : During the measurement and immediately afterwards.iieecamarines clfjr 24 . Preventive maintenance of Electrical equipment . Preventive maintenance of Electrical equipment . is calculated by multiplying the rated voltage Un. Insulation resistance The minimum insulation resistance of new. R.Three points are worth mentioning in this connection: Insulation resistance. with the constant factor 0.. cleaned or repaired windings with respect to ground is 10 Megohm or more. Measurement and Checking.5 Megohm/kV. 1.iieecamarines clfjr 25 . The minimum insulation resistance. iieecamarines clfjr 26 . The winding temperature should be 25°C ± 15°C.. Maximum insulation resistance should be measured with 500 V DC with the windings at a operating temperature of 80 – 120°C depending on the motor type and efficiency. Measurement Minimum insulation resistance of the winding to ground is measured with 500 V DC. Preventive maintenance of Electrical equipment .2. iieecamarines clfjr 27 . the minimum insulation resistance may drop to a critical level. the reason might be that the windings are humid and need to be dried. As long as the measured value does not fall below the calculated value of minimum insulation resistance.3. the motor can continue to run. Checking If the insulation resistance of a new.. Preventive maintenance of Electrical equipment . If the motor has been operating for a long period of time. cleaned or repaired motor that has been stored for some time is less then 10 megaohm. iieecamarines clfjr 28 . in order to avoid that people get hurt due to the high leakage voltage. Preventive maintenance of Electrical equipment . if it drops below this limit.. the motor has to be stopped immediately.However. ambient temperatures above 40° C may result in the allowable motor temperature rise to be lowered. Preventive maintenance of Electrical equipment . Conversely. which effectively de- rates the motor output.iieecamarines clfjr 29 . Ambient temperatures below –30° C can require special bearing lubricant and material requirements.Factors affecting the winding insulation resistance Ambient temperature is often overlooked as a design criteria.. Instrument use in testing of insulation of the equipment Preventive maintenance of Electrical equipment .iieecamarines clfjr 30 .. .Preventive maintenance of Electrical equipment .iieecamarines clfjr 31 . .iieecamarines clfjr 32 .Preventive maintenance of Electrical equipment . .Preventive maintenance of Electrical equipment .iieecamarines clfjr 33 . iieecamarines clfjr 34 ..Hydro power plant Preventive maintenance of Electrical equipment . iieecamarines clfjr 35 .A general rule-of-thumb is 10 Megohm or more. Insulation resistance value Insulation level 2 Megohm or less Bad 2-5 Megohm Critical 5-10 Megohm Abnormal 10-50 Megohm Good 50-100 Megohm Very good 100 Megohm or more Excellent Preventive maintenance of Electrical equipment .. iieecamarines clfjr 36 .Class insulation Preventive maintenance of Electrical equipment .. iieecamarines clfjr 37 .Preventive maintenance of Motor Control Preventive maintenance of Electrical equipment .. Cleaning of contacts Preventive maintenance of Electrical equipment ..iieecamarines clfjr 38 . .Generator breaker Preventive maintenance of Electrical equipment .iieecamarines clfjr 39 . .Winding resistance tester -DLRO use to measure the low resistance of the winding in terms of micro ohms Preventive maintenance of Electrical equipment .iieecamarines clfjr 40 . Testing of Transformer Preventive maintenance of Electrical equipment ..iieecamarines clfjr 41 . iieecamarines clfjr 42 ..Windings to ground Preventive maintenance of Electrical equipment . iieecamarines clfjr 43 .Motor – testing of insulation resistance Winding to winding Winding to ground Preventive maintenance of Electrical equipment .. .iieecamarines clfjr 44 .Preventive maintenance of Electrical equipment . .iieecamarines clfjr 45 .Preventive maintenance of Electrical equipment . .iieecamarines clfjr 46 .Preventive maintenance of Electrical equipment . .Preventive maintenance of Electrical equipment .iieecamarines clfjr 47 .
Report "Maintenance of Electrical Equipment Electrician RME"