S&C Instruction Sheet 663-590
9
Table 2
Table 2. Inspection Procedures for Pad-Mounted Gear Equipped with AT-12 Source-Transfer Control
①—
Continued
Item
Procedures
Optional overcurrent-
lockout feature (“62LR”
timer)
1 . With the MANUAL/AUTOMATIC operation selector switch in the
Automatic position, simulate a fault cleared by feeder fuses
by momentarily pressing the SIMULATE-OVERCURRENT test switch for the preferred source . Verify the OVERCURRENT-
LOCKOUT lamp lights for a period within ±20% of the setting on the “62LR” timer .
2 . Now, simulate a lockout resulting from a fault cleared by a source-side protective device . To accomplish this, press the SIMULATE
OVERCURRENT test switch for the preferred source and confirm the OVERCURRENT-LOCKOUT lamp lights . Then, press and
hold in the associated SIMULATE-LOSS-OF-SOURCE test switch . Release the test switch when the preferred-source operator
opens and verify the alternate-source operator remains open and locked out .
3 . Place the MANUAL/AUTOMATIC operation selector switch in the
Manual position, and press the OVERCURRENT-LOCKOUT
RESET pushbutton to cancel the lockout condition . Confirm the OVERCURRENT-LOCKOUT lamp extinguishes . Then, close the
preferred-source operator by pressing the appropriate CLOSE pushbutton .
Before leaving the
gear…
So the AT-12 control is ready for automatic operation when leaving the site, perform the following:
1 . With the MANUAL/AUTOMATIC operation selector switch in the
Manual position, recouple both operators to their associated
Mini-Rupter Switches .
2 . Place the MANUAL/AUTOMATIC operation selector switch in the
Automatic position .
3 . Confirm both source voltage lamps and the READY lamp are illuminated . (If the READY lamp is not lit, refer to the conditions
required to light the READY lamp listed on the label above the control .)
4 . Close and padlock all doors .
①
If the source-transfer pad-mounted gear being inspected does not oper-
ate as indicated in these inspection recommendations, refer to the AT-12
troubleshooting guide, S&C Instruction Sheet 514-520 . If further assistance
is needed, contact the nearest S&C Sales Office . Have the complete catalog
number of the gear, date of shipment (as shown on the nameplate), operating
modes, and timer settings .
