Siemens Siprotec 7VK61 Manual page 83

• Measuring request from the manual CLOSE detection. The manual CLOSE detection of the central function
control (Section 2.8.1) issues a measuring request provided that this was configured in the power system
data 2 (Section 2.1.5.1, address 1151). This requires that the device is informed of the manual closing via
binary input „>Manual Close" (no. 356). The release conditions for manual closure apply (parameter
MC...).
• Request to execute a check synchronism measurement from an external closing command. Binary input
„>Sync. Start MC" FNo. 2905 fulfills this purpose. Unlike the „>Manual Close" (see previous para-
graph), this merely affects the measuring request to the synchronism check function, but not other integrated
manual CLOSE function such as instantaneous tripping when switching onto a fault (e.g. accelerated trip-
ping of a time overcurrent stage). The release conditions for manual closure apply.
• Measuring request from the integrated control function via control keys or via the serial interface using DIGSI
on a PC or from a control centre. The release conditions for manual closure apply (parameter MC...).
The synchronism-check function gives permission for passage „Sync. release" (No. 2951) of the closing
command to the required function. Furthermore, a separate closing command is available as output indication
„Sync.CloseCmd" (No. 2961).
The check of the release conditions is limited by an adjustable synchronous monitoring time T-SYN.
DURATION. The configured conditions must be fulfilled within this time. If they are not, the synchronism will not
be checked. A new synchronism check sequence requires a new request.
The device generates messages if, after a request to check synchronism, the conditions for release are not
fulfilled, i.e. if the absolute voltage difference AR maxVolt.Diff or. MC maxVolt.Diff, frequency difference
AR maxFreq.Diff or MC maxFreq.Diff or angle difference AR maxAngleDiff or MC maxAngleDiff
lie outside the permissible limit values. A precondition for these indications is that voltages within the operating
range of the relay are available. When a closing command originates from the integrated control function and
the conditions for synchronism are not fulfilled, the command is cancelled, i.e. the control function outputs „CO–
" (refer also to Section 2.10.1).
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
2.4 Synchronism and voltage check (optional)
Functions
83