tn: time delay of step n, given in s. This setting is dependent of the protection
application. In many applications the protection function shall not directly trip when
there is a short circuit or ground faults in the system. The time delay must be
coordinated to the short circuit protections.
tResetn: Reset time for step n if definite time delay is used, given in s. The default
value is 25 ms.
tnMin: Minimum operation time for inverse time characteristic for step n, given in s.
When using inverse time characteristic for the undervoltage function during very low
voltages can give a short operation time. This might lead to unselective trip. By setting
t1Min longer than the operation time for other protections such unselective tripping can
be avoided.
ResetTypeCrvn: This parameter for inverse time characteristic can be set to
Instantaneous, Frozen time, Linearly decreased. The default setting isInstantaneous.
tIResetn: Reset time for step n if inverse time delay is used, given in s. The default
value is 25 ms.
TDn: Time multiplier for inverse time characteristic. This parameter is used for
coordination between different inverse time delayed undervoltage protections.
ACrvn, BCrvn, CCrvn, DCrvn, PCrvn: Parameters to set to create programmable under
voltage inverse time characteristic. Description of this can be found in the technical
reference manual.
CrvSatn: When the denominator in the expression of the programmable curve is equal
to zero the time delay will be infinity. There will be an undesired discontinuity.
Therefore, a tuning parameter CrvSatn is set to compensate for this phenomenon. In
the voltage interval Pickup> down to Pickup> · (1.0 - CrvSatn/100) the used voltage
will be: Pickup> · (1.0 - CrvSatn/100). If the programmable curve is used this
parameter must be calculated so that:
EQUATION1448 V1 EN (Equation 400)
IntBlkSeln: This parameter can be set to Disabled, Block of trip, Block all. In case of a
low voltage the undervoltage function can be blocked. This function can be used to
prevent function when the protected object is switched off. If the parameter is set Block
of trip or Block all unwanted trip is prevented.
IntBlkStValn: Voltage level under which the blocking is activated set in % of VBase.
This setting must be lower than the setting Pickupn. As switch of shall be detected the
setting can be very low, that is, about 10%.
Section 3 1MRK504116-UUS C
IED application
512
Application manual
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