Omicron CP TD1 - DF Limits of Bushings (B)

143
Appendix
12.7 DF Limits of Bushings (B)
Source: US Bureau of Reclamation: "Testing and Maintenance of High Voltage
Bushings", Facility instructions, standards and techniques -vol 3-2, Denver,
1991
Manufacturer Bushing Type or
Class
Initial P.F. for
new
bushings, at
Dangerous
P.F. value at
20 x C (%)
General Electric A 6.0 8.0
B 10.0 12.0
F1.52.0
L34.0
LC 2.5 3.5
OF 2.6 6.0
S3.56.0
U1.01.5
Lapp bushings POC 0.5
PRC 0.7 - 1.2
Ohio Brass
manufactured prior to
1926 and after 1938
ODOF
G
L
1 - 10 Initial P.F. =22
Ohio Brass
manufactured 1926 to
1938, inclusive
ODOF
G
L
2 - 4 Initial P.F. =16
Ohio Brass Class GK type C 0.4 - 0.6
Class LK type A 0.6 - 0.7
Pennsylvania
Transformer
P
PA
PB
0.5 1.0
Westinghouse D 6.0
O1.4
OCB & Inst. Trans.
69kV and below
3.5
OCB & Inst. Trans.
92kV - 138kV
2.8
Power & Dist.
Trans. OCB
161kV - 288kV
2.0