faridabad transformers optimal condition transformers core experienced technicians action removal specialized equipment critical aspects hardworking piece reliable delivery unsung heroes oil clean oil improving oil hindering onsite filtration moisture reduces transformer oil transformer maintenance transformer oil filtration time transformer oil operations oil testing advanced filtration techniques moisture particulate matter require regular maintenance ensure safe operation oils insulating properties repairs increased safety dielectric strength trained location minimizing disruption failure costly repairs windings preventing overheating dissipates heat generated primary purposes insulation