Indicators
Understanding the Pole-Unit
Position Indicators
The pole-unit position indicators are located
underneath the pole-unit base.
The indicators
are not meaningful while the pole-units are
being closed and charged.
If the pole-unit is “OPEN” and discharged, the
indicator reads “OPEN.” See Figure 79.
“OPEN” and
discharged
Figure 79. The pole-unit is “OPEN” and discharged. The indicator reads
“OPEN.”
If the pole-unit is “CLOSED” and charged,
the indicator reads “CLOSED.” See Figure 80.
“CLOSED”
and charged
Figure 80. The pole-unit is “CLOSED” and charged. The indicator reads
“CLOSED.”
Figure 81. Gauge needle in white “OK” to operate zone.
“OK” to
operate zone
Understanding the Gas-Pressure
Gauge
A temperature-compensated gas-pressure gauge
is provided under the base of each pole-unit. It
shows whether SF
6
gas density is sufficient for
a trip operation. The gas-pressure gauge shows
three zones:
OK to operate:
This is the white zone. If the gauge needle is in
this zone, the pole-unit is at normal gas density,
and can be opened and closed. See Figure 81.
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S&C Instruction Sheet 731-502
