6.15
Date Code 20080213 Instruction Manual SEL-351A Relay
Close and Reclose Logic
Reclosing Relay
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 (see Reclosing Relay Shot Counter
on page 6.18).
➤ The front-panel LEDs RS, CY, and LO are all extinguished, a
ready indication that the recloser is defeated.
Close Logic Can Still Operate When the Reclosing Relay Is Defeated
If the reclosing relay is defeated, the close logic (see Figure 6.1) can still
operate if SEL
OGIC control equation circuit breaker status setting 52A is set to
something other than numeral 0. Making the setting 52A = 0 defeats the close
logic and also defeats the reclosing relay.
For example, if 52A = IN101, a 52a circuit breaker auxiliary contact is
connected to input IN101. If the reclosing relay does not exist, the close logic
still operates, allowing closing to take place via SEL
OGIC control equation
setting CL (close conditions, other than automatic reclosing). See Close Logic
on page 6.2 for more discussion on SEL
OGIC control equation settings 52A
and CL. Also see Optoisolated Inputs on page 7.2 for more discussion on
SEL
OGIC control equation setting 52A.
Reclosing Relay
Timer Settings
The open interval and reset timer factory settings are shown in Table 6 . 2.
The operation of these timers is affected by SEL
OGIC control equation settings
discussed later in this section. Also, see the Settings Sheets at the end of
Section 9: Setting the Relay.
Table 6.2 Reclosing Relay Timer Settings and Setting Ranges
Timer Setting
(range)
Fac tory Se tt ing
(in cycles)
Definition
79OI1 (0.00–999999 cyc) 300.00 open interval 1 time
79OI2 (0.00–999999 cyc) 0.00 open interval 2 time
79OI3 (0.00–999999 cyc) 0.00 open interval 3 time
79OI4 (0.00–999999 cyc) 0.00 open interval 4 time
79RSD (0.00–999999 cyc) 1800.00 reset time from reclose cycle state
79RSLD (0.00–999999 cyc) 300.00 reset time from lockout state
Courtesy of NationalSwitchgear.com
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