64
Installation and commissioning guide
2750 515-1 EN, REV. 14, 2020-06-26
* Reference values from ABB Components.
Dissipation factor, tan δ
The dissipation factor varies with the temperature of the bushing core, and thus the measured dissipation
factor must be multiplied with the correction factor given below.
Bushing core temperature °C Correction factor to 20 °C (IEC)
0-2 0.80
3-7 0.85
8-12 0.90
13-17 0.95
18-22 1.00
23-27 1.05
28-32 1.10
33-37 1.15
38-42 1.20
43-47 1.25
48-52 1.30
53-57 1.34
57-62 1.35
63-67 1.35
68-72 1.30
73-77 1.25
78-82 1.20
83-87 1.10
Procedure
1. De-energize the transformer.
2.
Disconnect the external connections from the outer terminal of the bushing.
3.
Remove the cover (58).
G005047