S&C Mark VI, Instruction Sheet

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S&C Instruction Sheet 712-501
Understanding the
Remote Gas-Density Indicator
If furnished, the remote gas-density indicator
provides contacts for each interrupter that
allow remote monitoring of two low-gas-pres-
sure alarms:
Level 1 Alarm:
When a Level 1 Alarm is issued, the interrupter
can be opened and closed as usual . However,
the interrupter has lost gas and should be
replaced as soon as possible .
The remote gas-density Level 1 alarm con-
tact opens at 93% of normal density, or 70 PSIG
at 68°F (20°C) . Contacts are normally closed at
normal operating gas pressure .
Level 2 Alarm:
When a Level 2 Alarm is issued, the gas den sity
in the interrupter has dropped below the mini-
mum functional level . The interrupter will not
maintain full interrupting or dielectric rat ings .
The interrupter should be removed from service
and replaced promptly .
DO NOT oper ate this
Mark VI Circuit-Switcher .
The remote gas-density Level 2 alarm con-
tact opens at 88% of normal density, or 65 PSIG
at 68° (20°C) . Contacts are normally closed at
normal operating gas pressure .
NOTICE
At temperatures below -31°F (-35°C), a
Level 2 Alarm may be issued due to the cold
temperature . At such low tempera tures, gas
density is below the interrupter’s minimum
functional level, so the inter rupter will not
have full interrupting or dielectric ratings .
At these temperatures, a Level 2 Alarm
does not accurately indicate whether an
interrupter is losing SF
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Indicators