Date Code 20001006 Close and Reclose Logic 6-15
SEL-351 Instruction Manual
These reclosing relay SELOGIC Control Equation factory settings can be used in any
firmware version. It is logically redundant in firmware versions with the OPEN command
imbedded to drive the reclosing relay to lockout, but this is no problem.
Reclosing Relay States and Settings/Setting Group Changes
If individual settings are changed for the active setting group or the active setting group is changed,
all of the following occur:
• The reclosing relay remains in the state it was in before the settings change.
• The shot counter is driven to last shot (last shot corresponding to the new settings; see
discussion on last shot that follows).
• The reset timer is loaded with reset time setting 79RSLD (see discussion on reset timing
later in this section).
If the relay happened to be in the Reclose Cycle State and was timing on an open interval before
the settings change, the relay would be in the Reclose Cycle State after the settings change, but the
relay would immediately go to the Lockout State. This is because the breaker is open, and the
relay is at last shot after the settings change, and thus no more automatic reclosures are available.
If the circuit breaker remains closed through the settings change, the reset timer times out on reset
time setting 79RSLD after the settings change and goes to the Reset State (if it is not already in the
Reset State), and the shot counter returns to shot = 0. If the relay happens to trip during this reset
timing, the relay will immediately go to the Lockout State, because shot = last shot.
Defeat the Reclosing Relay
If any one of the following reclosing relay settings are made:
• Reclose enable setting E79 = N.
• Open Interval 1 time setting 79OI1 = 0.00.
then the reclosing relay is defeated, and no automatic reclosing can occur. These settings are
explained later in this section. See also the settings sheets at the end of Section 9: Setting the
Relay.
If the reclosing relay is defeated, the following also occur:
• All three reclosing relay state Relay Word bits (79RS, 79CY, and 79LO) are forced to
logical 0 (see Table 6.1).
• All shot counter Relay Word bits (SH0, SH1, SH2, SH3, and SH4) are forced to logical 0
(the shot counter is explained later in this section).
• The front-panel LEDs RS, CY, and LO are all extinguished — a ready indication that the
recloser is defeated.
Courtesy of NationalSwitchgear.com
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