2 Functions
102
7SD610 Manual
C53000-G1176-C145-4
The pickup of the phase current stages is non-directional, if address 2680
Direction Iph> is parameterized to Non-Directional. The pickup of the earth
stage is non-directional, if address 2683 Direction 3I0> is parameterized to Non-
Directional.
The setting values for the phase current is Iph> Dir., and 3I0> Dir. for the earth
current. Currents above the associated pickup value are detected and signalled. After
expiry of the associated time delays T Iph> Dir. or T 3I0> Dir. a trip command
is issued. The dropout value is approximately 7% less than the pickup value, but at
least 1.8% of the nominal current, below the pickup value. .
Figure 2-40 shows the logic diagram of the I>ger stages. The stages can be blocked
via the binary input „>BLOCK Dir. I>“. Additionally, the earth current can be
blocked separately via a binary input „>BLOCK Dir. Iep“.
During fuse failure or pickup of the Fuse Failure Monitor all stages which are parame-
terized as Forward or Reverse are blocked. During the single-pole pause, the earth
current stage is always blocked to avoid a fault trigger.
The binary input „>O/C InstTRIP“ and the evaluation of the indication „switch“
(onto fault) can separately affect the phase and/or earth current stages. This can be
achieved with two parameters:
• I>Dir.Telep/BI (address 2686), determines whether a non-delayed trip of this
stage via binary input „>O/C InstTRIP“ is possible (YES) or impossible (NO). This
parameter is also used for instantaneous tripping before automatic reclosure.
• I> Dir. SOTF (address 2687), determines whether this stage shall issue non-
delayed tripping (YES) or not (NO) in case of switching-onto-fault conditions.
From the individual phase or earth current specific direction determination (7240 to
7247) the indications„O/C Dir.forward“ or „O/C Dir.reverse“ are created, if
there is a valid result of the direction determination for a phase or earth current (for-
ward or backward). These indications can then be transferred to a different device and
there cause an immediate trip if an overcurrent stage of the receiving device has
picked up. The indications are then via CFC combined with a logical OR function.
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