Maintenance of Electrical Equipment

1. Maintenance of Electrical Equipments
Prepared By: Aesha K. Joshi(LEE)

2. Flow of presentation
 Introduction
 Types of maintenance
 Effects of poor maintenance
 Maintenance schedule of equipments
 Probable faults due to poor maintenance

3. Introduction
 It is necessary to carry out periodic maintenance after
the equipment is purchased and put in to service
 The machine/equipment can stop working at any time
if regular maintenance is not carried out
 In some important industrial processes like power
station, substation etc. it is essential that the system
works continuously without interruption and proper
maintenance is necessary for this

4. Types of maintenance
 The following are types of maintenance:
 Preventive maintenance
 Routine maintenance
 Periodic maintenance
 Breakdown maintenance

5. Preventive maintenance
 The preventive maintenance is the maintenance
carried out regularly at certain intervals so that the
equipment gives service for long period without giving
trouble.
 Preventive maintenance in case of electrical
equipments includes inspection, testing, cleaning,
drying, varnishing, lubrication of the equipment as per
the schedule

6. Advantages of preventive
maintenance
 Great damage to the equipment is prevented
 Cost of repair decreases
 Equipment works continuously without giving any
trouble for long period
 Due to above reason the monetary loss does not occur
 Due to regular maintenance equipment works without
noise so there is increase in efficiency of the operator
 Quality of production becomes uniform
 Reduces possibility of accident

7. Routine maintenance
Routine maintenance includes general activities of
maintenance. The activities include the following.
1. Visual inspection
2. Cleaning
3. Lubrication

8. Periodic maintenance
 In this the machine is stopped for some period and the
activity of maintenance is carried out. In this following
activities are included:
Testing and recording
Re varnishing
Drying
Alignment/Adjustment
Replacement of worn out parts

9. Breakdown maintenance
 Sometime a machine or equipment stops working if
the regular preventive maintenance has been carried
out. When maintenance is done in such condition it is
called breakdown maintenance.

10. Conti…
 Following activities are performed during breakdown
maintenance:
 Locating problem
 Trouble shooting
 Repairing
 Replacement of damaged items
 Re commissioning of equipment

11. Overhauling
 Overhaul and scheduled maintenance both are parts
of preventive maintenance but there is difference
between two
 During overhaul the machine is stopped and
maintenance is done while during schedule
maintenance machine is not opened

12. Conti…
 Activities performed during overhauling of the electrical
equipment:
 Visual inspection
 Dismantling
 Cleaning
 Replacement of worn out parts
 Cleaning and re varnishing of winding
 Drying
 Assembly
 Testing
 Re commissioning

13. Reasons of failure of an equipment
due to poor maintenance
The machine or equipment can stop working if proper
maintenance is not done. The probable reasons for this
are as follows:
Poor cleanliness of the equipment
Presence of moisture
Poor ventilation
Poor insulation
Wear and tear

14. Faults in electric machine due to
poor maintenance
 Efficiency of the machine decreases
 Capacity of machine decreases
 Temperature of machine increases
 Increase in bearing temperature
 Possibility of occurring short circuit
 Possibility of occurring earth fault
 The machine can catch fire
 Serious accident may occur
 Power supply to the machine can be interrupted

15. Factors to be considered while
preparing maintenance schedule
 Size of the machine
 Type of the machine
 Site at which the equipment is installed
 Protective gear of the equipment
 Accessories of the equipment
 Mode of operation of the plant
 Likely hood of failure
 Cost of maintenance
 Consequences of outage
 Cost of standby machine

16. Frequency of maintenance
 The frequency of maintenance depends upon the
following factors:
 Importance of the machine
 Duty cycle
 Overloads and service conditions
 Age of the machine or equipment

17. Thank you