Basic Features; Apparatus Control; Interlocking - ABB REC 561 User Manual

1MRK 580 146-XEN
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3 Basic features

3.1 Apparatus control

3.2 Interlocking

Introduction - REC 561
The apparatus control function performs open and close commands of
high-voltage apparatuses in one bay and indicates the status. The function
handles commands coming from different operator places, that is, from
the station MMI, control centre, or local panel. Permission to operate is
given after evaluation of conditions from other functions such as inter-
locking, synchro-check, operator mode, or external conditions.
Other apparatus control functions include:
• Selection and reservation function to prevent double operation
• Command supervision
• Selection of operator place
• Block/deblock of operation
• Block/deblock of updating of position indications
• Manual setting of position indications
• Overriding of the reservation and interlocking functions
• Pole discordance protection.
The pole discordance protection applies to circuit breakers with individual
operation gears per pole or phase and is based on checking the positions
of the auxiliary contacts of the breaker. A discordance caused by one pole
failing to close or to open can be tolerated only for a limited time, for
instance, as a single-phase open time in connection with single-phase
reclosing.
The apparatus control function in REC 561 is prepared to be connected to
a dedicated control panel for local control. This panel can have a switch
for selection of the operators' mode; station/remote, local, or back-up. In
station/remote mode, the station is controlled from the station MMI or the
control centre, depending on the selection from a VDU or station switch.
Control from the local panel can only occur in local or back-up mode. The
local mode ensures that the interlocking requirements are fulfilled during
all operations, while the back-up mode is used in emergency situations
without interlocking. Hence the back-up mode bypasses the interlocking,
that is, the REC 561.
Interlocking means inhibiting the operation of high-voltage apparatuses in
a switchgear to prevent damage of the switchgear and personal injury to
operators. The basic interlocking functions are made for single or double-
breaker arrangement for one bay.
The interlocking function consists of software modules located in each
control terminal. For the station-wide interlocking, communication
between modules in different bays is performed via the communication
bus or hard-wired via the binary inputs/outputs.
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