sop for Preventive Maintenance of Transformers

1.0 Objective
To lay down a procedure Preventive Maintenance of Transformers.
2.0 Scope
This Standard Operating Procedure is applicable for Preventive Maintenance of Transformers to be followed at formulation plants
3.0 Responsibility
3.1 Officer / Executive Engineering shall be responsible for the execution of this procedure.
3.2 Engineering Manager shall be responsible for the implementation of this SOP.
3.3 Head QA/designee should be responsible for compliance of this SOP.

Electricity distribution transformer with cooling ribs

4.0 Abbreviations and Definitions
SOP : Standard Operating Procedure
No : Number
QA : Quality assurance
ER : Engineering
VCB : Vacuum Circuit Breaker
GO : Gang Operated
5.0 Procedure
5.1 General Conditions
5.1.1 Refer the master plan of preventive maintenance.
5.1.2 Equipment shall be available for preventive maintenance.
5.1.3 Clean oil / grease stains & remove unwanted material, spares after completion of work.
5.2 Precautions
5.2.1 Use necessary safety wears, while doing the work.
5.2.2 Ensure covers & guards are properly fixed.
5.3 Procedure For Preventive Maintenance Of Transformers
5.3.1 Ensure that electrical supply is in off position in main panel and display “under maintenance” Board on the panel board.
5.3.2 Switch OFF the drive unit and inform all the concerned.
5.3.3 Operator or above has to ensure and verify the check points for the preventive maintenance as shown in theAnnexure-1&2.
5.3.4 After the completion of preventive maintenance, check the machine for smooth operation.
5.3.5 Remove “Machine under Maintenance” Board on the panel board after completion of the Maintenance.
5.3.6 The operator / technician who perform the job will enter his name / sign in “Done By” Column and responsible

Engineer/ Officer and Head- Engineering will put sign in “Checked by” column.
5.3.7 Half Yearly Maintenance will include the jobs of Quarterly maintenance.
5.3.8 Quarterly Preventive Maintenance is to be carried out as per the following check points.
5.3.8.1 Check the on load tap changer driving mechanism.
5.3.8.2 Check the on load tap changer automatic control.
5.3.8.3 Check the Insulation resistance.
5.3.8.4 Check the oil level; it should be up to mark (sight glass).if required top up it.
5.3.8.5 Check the control and interlocks.
5.3.9 Half Yearly Preventive Maintenance is to be carried out as per the following check points.
5.3.9.1 Check the relay settings.
5.3.9.2 Check and tighten the electrical cable connection of transformer.
5.3.9.3 Check the oil of transformer.
5.3.9.4 Remove the silica gel and dry it into the sunlight until the colour turns blue else replace the same.
5.3.9.5 Check the Quarterly list as per annexure -1
6.0 Forms and Records
6.1 Quarterly Preventive Maintenance Check List of Transformers. – Annexure-1
6.2 Half yearly Preventive Maintenance Check List of Transformers. – Annexure- 2
7.0 Distribution
7.1 Master copy – Documentation Cell (Quality Assurance)
7.2 Controlled copies – Engineering department

sop for Preventive Maintenance of Transformers

Leave a Comment Cancel reply