38
Maintenance or Test
Recommended Interval
Reference
Review equipment ratings
5 years
NERC Planning Standard
Preventive maintenance
Per manufacturer's
recommendations
recommendations
Mfr. Instruction Books
Transformer physical
inspection
inspection
Annually
NFPA 70B, 7-2 and
Appendix H
Transformer FIST
Volume 3-30
Appendix H
Transformer FIST
Volume 3-30
Bushings - visual
inspection
inspection
Quarterly and 3-5 years
Doble Bushing Field Test
Guide
IEEE P62-1995
Transformer FIST
Volume 3-30
Guide
IEEE P62-1995
Transformer FIST
Volume 3-30
Bushings - check oil level
Weekly
PO&M 19
Transformer FIST
Volume 3-30
Transformer FIST
Volume 3-30
Bushings - cleaning
3-5 years
Transformer FIST
Volume 3-30
Volume 3-30
Transformer and
bushings - Doble test
bushings - Doble test
3-5 years
(6 months to 1 year for
suspect bushings)
(6 months to 1 year for
suspect bushings)
FIST Volume 3-2
Doble Bushing Field Test
Guide
IEEE P62-1995, 6.2
Transformer FIST
Volume 3-30
Doble Bushing Field Test
Guide
IEEE P62-1995, 6.2
Transformer FIST
Volume 3-30
Transformer and
bushings - infrared scan
bushings - infrared scan
Annually
NFPA 70B, 18-17
Transformer FIST
Volume 3-30
Transformer FIST
Volume 3-30
Core - ground and
insulation resistance
insulation resistance
If DGA shows hot metal
gasses
gasses
Transformer FIST
Volume 3-30
Volume 3-30
Insulating oil - dissolved
gas analysis, physical, and
chemical tests
gas analysis, physical, and
chemical tests
Annually after first year of
operation
operation
NFPA 70B
FIST Volume 3-5
Transformer FIST
Volume 3-30
FIST Volume 3-5
Transformer FIST
Volume 3-30
Windings and core -
Insulation resistance test
Insulation resistance test
3-5 years or if DGA indicates
IEEE P62-1995, 6.1.5
NFPA 70B 7-2 and
Appendix H
Transformer FIST
Volume 3-30
NFPA 70B 7-2 and
Appendix H
Transformer FIST
Volume 3-30
Cooling fans - inspect and
test
test
Annually Transformer
FIST
Volume 3-30
Oil pumps and motors -
inspect and test
inspect and test
Annually Transformer
FIST
Volume 3-30