Thermal Overload Blocking - ABB 615 series Technical Manual

Section 9
Control functions
9.4.3.4
994
second unit, that is the slave, is released to complete the reclose shot. With persistent
faults, the breaker reclosing is limited to the first breaker.
A070877 V1 EN
Figure 503: Master and slave scheme
If the AR unit is defined as a master by setting its terminal priority to high:
• The unit activates the CMD_WAIT output to the low priority slave unit whenever a
shot is in progress, a reclosing is unsuccessful or the BLK_RCLM_T input is active
• The CMD_WAIT output is reset one second after the reclose command is given or if
the sequence is unsuccessful when the reclaim time elapses.
If the AR unit is defined as a slave by setting its terminal priority to low:
• The unit waits until the master releases the BLK_RECL_T input (the CMD_WAIT
output in the master). Only after this signal has been deactivated, the reclose time for
the slave unit can be started.
• The slave unit is set to a lockout state if the BLK_RECL_T input is not released within
the time defined by the Max wait time setting , which follows the initiation of an
autoreclosing shot.
If the terminal priority of the AR unit is set to "none", the AR unit skips all these actions.

Thermal overload blocking

An alarm or pickup signal from the thermal overload protection 49F can be routed to the
input BLK_THERM to block and hold the reclose sequence. The BLK_THERM signal does
not affect the starting of the sequence. When the reclose time has elapsed and the
BLK_THERM input is active, the shot is not ready until the BLK_THERM input deactivates.
Should the BLK_THERM input remain active longer than the time set by the setting Max
Thm block time, the AR function goes to lockout.
If the BLK_THERM input is activated when the auto wait timer is running, the auto wait
timer is reset and the timer restarted when the BLK_THERM input deactivates.
1MAC059074-MB A
615 series ANSI
Technical Manual