28
S&C Instruction Sheet 716-502
Operation
Figure 27. The normal gas-pressure indicator and relief device.
Gas-pressure indicator
Safety relief device
Figure 28. The visible “red target” gas pressure indicator.
Red target
(semiphore)
Understanding the Gas-Pressure Indicator
and Safety Relief Device
Series 2000 Circuit-Switchers have sealed interrupters
containing gas under pressure. Loss of gas pressure may result
in improper interrupting action. Low gas pressure is signaled
by a red target in the GAS PRESSURE indicator at the upper
terminal end of the interrupter.
Figure 27 illustrates a GAS PRESSURE indicator with
acceptable gas pressure.
Figure 28 illustrates a GAS PRESSURE indicator with a red
target, signaling a loss in gas-pressure.
Understanding the Optional Remote Gas-
Density Monitor
The remote gas-density monitor provides local and remote
indication of the gas density in each interrupter in terms
of percent full. The system can be wired to provide remote
indication of the gas density of each interrupter via three
analog 0 to 1.0 mA dc outputs. The LCD screen provides
indication of gas density and alarms for each interrupter. The
remote gas-density monitor transmits updated measurements
approximately once per hour.
The remote gas-density monitor has three available
alarm contacts. The system provides both local and remote
indication of alarms.
Level 1 Alarm
indicates an interrupter is leaking. The
circuit-switcher can still be operated, but the leaking inter-
rupter should be replaced promptly.
Level 2 Alarm
indicates an interrupter has lost enough
SF6 gas it can no longer clear faults properly.
System Trouble Alarm
indicates a problem with the
monitoring system. A system trouble alarm will activate
when the receiver fails to receive a signal for over 24 hours.
The system trouble alarm will also activate when there are
approximately three months or less of battery life remaining.
At first, a Low-Battery alarm will appear locally. After the
battery has completely discharged, an “Error” message will
appear in place of the percent-gas-density information, and
the system trouble alarm will signal remotely.
For complete instructions on installing, operating, and
troubleshooting the optional remote gas-density monitor, refer
to S&C Instruction Sheet 716-530.
Inspection Recommendations
To ensure the Series 2000 Circuit-Switcher’s continued proper
performance, the circuit-switcher should be inspected in
accordance with S&C-recommended schedule and procedures
contained in S&C Instruction Sheet 716-590.
