Page 370 - Offshore Electrical Engineering Manual

Sulphur Hexafluoride Switchgear 357

cylinder. If the gas system has a topping up compressor, the compressor gas
supply, oil level, filters or desiccants should be checked for good condition.
The permanently fitted gas pressure gauge should be checked against a recently
calibrated test gauge.

As contact mechanisms tend to be inaccessible in this type of switchgear, electri-
cal testing should include timing and travel tests, subject to the unit being properly
equipped for this to be carried out. The results may then be compared with those
provided by the manufacturer, with discrepancies indicating a fault in the operating
mechanism or contact wear.