Such a disconnection of an end will result in the setting to zero of all current scan
values for the relevant phase (phase current and residual current).
All functions (e.g. protection functions, limit value monitoring, operating data
measurement, etc.) will continue to operate unaffected, with these values set to
zero.
With the differential protection function the formula to calculate the restraining
current is not changed by disconnecting ends, even though only two ends may
be left.
Disconnecting ends may only be carried out with binary signal input functions.
Starting via operating parameters (or command sent through a communications
interface) is not possible.
(041 019) MAIN: Disconnect End a EXT
(041 107) MAIN: Disconnect End b EXT
(041 128) MAIN: Disconnect End c EXT
(041 129) MAIN: Disconnect End d EXT
The binary signal input functions listed above must be continuously present
when disconnecting ends.
To enable the disconnection function, one of the following additional conditions
must be met:
●
All three phase currents at the relevant end must be below 0.05 I
nom
:
Disconnection of the end will be permanent as soon as (immediately after)
the binary signal input function has started and this loss of load/
undercurrent condition is met.
Disconnection of the end will be permanently cancelled as soon as
(immediately after) the binary signal input function has ended and this loss
of load/undercurrent condition is met.
The P634 will continue to measure any current flow in the disconnected end
in order to check this loss of load/undercurrent condition, but will not
display these measured values.
●
The disconnection function, as an alternative to the loss of load/
undercurrent condition, can be enabled using another binary signal input
function (041 148) MAIN: En. disc. end x EXT
As soon as both binary signal input functions are present, disconnection of
the end will be effective.
As long as the enabling signal is not present at the binary signal input,
there is no status change, i.e. an existing disconnection of an end will
remain active independently of the disconnection request.
As soon as the disconnection request ends with the enable signal still
present at the binary signal input then the disconnection of the end will be
permanently cancelled.
3 Operation
P634
P634/EN M/R-42-A // P634‑311‑653 3-69
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