14
Maintenance or Test
Recommended Interval
Reference
Review equipment ratings
5 years
NERC Planning Standard
DC high potential test
(stepped or ramped voltage
method)
(stepped or ramped voltage
method)
3-6 years
1
FIST Volume 3-1
NFPA 70B
IEEE 400
NFPA 70B
IEEE 400
Oil tests (dissolved gas
analysis [DGA], dielectric,
acidity, color, interfacial
tension, water content,
power factor)
analysis [DGA], dielectric,
acidity, color, interfacial
tension, water content,
power factor)
Annually
FIST Volume 3-5
Infrared scan
Annually
NFPA 70B, 18-17
1
Except XLPE cables.
Coupling capacitors provide a path for communication frequency signals (traveling
over the transmission line) to reach communication and relaying equipment without
allowing power system frequency energy to pass. These are static devices requiring
relatively little maintenance. Except for infrared scanning, maintenance must be
conducted with equipment de-energized.
over the transmission line) to reach communication and relaying equipment without
allowing power system frequency energy to pass. These are static devices requiring
relatively little maintenance. Except for infrared scanning, maintenance must be
conducted with equipment de-energized.
Maintenance or Test
Recommended Interval
Reference
Review equipment ratings
5 years
NERC Planning Standard
Power factor
2 years
Doble Reference Book on
Cables and Accessories;
Doble Power Factor Test
Data Reference Book
Cables and Accessories;
Doble Power Factor Test
Data Reference Book
Infrared scan
Annually
NFPA 70B, 18-17