Table of Contents
Advertisement
6 Maintenance
6.1 Recommended maintenance
General
The bushings are maintenance free, no regular maintenance is necessary.
DANGER!
Risk of electrocution!
Do not go near the bushing while it is energized, or ungrounded. High voltages can kill you.
Make sure that the bushing is de-energized, and grounded before you do work on it.
Cleaning of the insulator surface
If the insulator shed is exposed to very high pollution, it can be necessary to clean the surface. Remove the
pollution with a moist cloth. If necessary, put isopropyl alcohol on the cloth.
DANGER!
1,1,1 -Trichloroethane or Methyl-chloride are not recommended as detergents, because they are
dangerous to persons and the environment.
CAUTION!
Do not wash the insulator sheds with a high pressure water jet. This can cause damage to the
insulator sheds.
Measurement of capacitance and dissipation factor
Please refer to Measurement of capacitance and dissipation factor, page 42.
Thermovision (infrared camera) check for local overheating on connectors
At the maximum rated current, the bushing outer terminal normally operates at a temperature of about
+35 °C to +45 °C above the ambient temperature. Significantly higher temperatures can be a sign of bad
connections, especially at lower current loading.
Checking of oil leakage
Make a visual inspection for oil leakage during regular station supervision.
After repairs
ABB recommends that the capacitance is measured after repairs have been done, and after service of
connected equipment or after work near the bushing is completed.
It is important to compare the capacitance before energization with the capacitance that was measured at
commisioning. A change in capacitance gives indication of a fault. Refer to Measurement of capacitance and
dissipation factor, page 42.
Installation and maintenance guide
1ZSC000563-AAX EN, REV. A, 2019-03-21
47
Advertisement
Table of Contents
