Functional Measured Values
Values Description Primary Secondary % Referenced to
(_:601:305) Time until trip Expected time until tripping s s s
(_:601:304) Time until close Time until close release s s s
(_:601:306) Overload phase A Thermal measured values of
the phases
% % Tripping temperature
(_:601:307) Overload phase B
(_:601:308) Overload phase C
(_:601:309) Overload maximum Thermal measured value of the
overload protection
% % Tripping temperature
(_:601:310) Equival. current phs
A
Current measured value which
serves as basis for the overload
measured value
A A Rated operating current
of the primary values
(_:601:311) Equival. current phs B
(_:601:312) Equival. current phs C
(_:601:313) Equival. current max. Maximum current measured
value which serves as basis for
the overload measured value
A A Rated operating current
of the primary values
Application and Setting Notes
Motors and generators as well as transformers are at risk from long-lasting overloads. You can adapt the given
overload characteristic curve to the user-defined characteristic curve with the Thermal overload protection,
user-defined characteristic curve function. You can find the predefined characteristic curve in the chapter
12.23 Thermal Overload Protection, User-Defined Characteristic Curve.
When setting the parameters, consider the following:
•
The settings for the used current transformer (primary values and secondary values) must be set correctly
in the power system.
•
The rated values for the protected object must be correct in the used function group.
Parameter: Threshold current warning
•
Recommended setting value (_:101) Threshold current warning = 1.1 A at I
rated
= 1 A
Set the threshold to the maximum permissible continuous current (I
max, perm
). This results in the same setting
value as for the first value of the user-defined characteristic curve.
Parameter: Threshold thermal warn.
•
Recommended setting value (_:104) Threshold thermal warn.= 90 %
If the first value of the user-defined characteristic curve is 1.1 of the rated current, the default setting can be
left. The thermal memory results for 83 % at continuously flowing rated object current.
If the first value of the user-defined characteristic curve is 1.05 of the rated object current, the thermal
memory for rated current is already 91 % filled. Increase the Threshold thermal warn. to 95 %.
Parameter: Dropout threshold operate
•
Recommended setting value (_:105) Dropout threshold operate= 90 %
The Dropout threshold operate parameter is used to drop out pickup and tripping when the value
drops below this threshold. A setting on the order of magnitude of the warning threshold is recommended.
You can select a lower setting value for special applications, desired additional cooling or longer blocking of
closing.
Note that the calculation of the operational measured value Time until close refers to this value.
6.20.4
Protection and Automation Functions
6.20 Thermal Overload Protection, User-Defined Characteristic Curve
670 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
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