Siemens 6MD85, Manual

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Dropout of Tripping
Once the thermal memory has fallen below the setting value of the
Dropout threshold operate
, the
trip command is canceled upon tripping. In contrast, the current-warning threshold and the thermal warning
threshold are reduced at a fixed dropout threshold (see Technical Data).
Behavior in the Event of Auxiliary-Voltage Failure
The behavior of the thermal replica can be controlled upon auxiliary-voltage failure via the setting parameter
Storage of thermal replica
. You can save the thermal state for a time of 500 min. Once the supply
voltage returns, the thermal replica continues to function with the saved thermal state.
If the thermal replica is not saved, it will be reset to 0 upon failure of the auxiliary voltage.
Resetting the Thermal Map
You can reset the thermal memory via the binary input indication
>Reset thermal replica
. The thermal
memory will then have a 0 value. A reparameterization will also lead to resetting the thermal memory.
Emergency Start
Depending on the operating conditions, tripping can be blocked or closure enabled despite the permissible
thermal limits being exceeded. Upon activation of the binary input signal
>Emergency start
, tripping is
blocked and closure enabled. This does not affect the state of the thermal memory. After the input
>Emer-
gency start
disappears, the blocking remains in effect for the set
Emerg. start T overtravel
.
Blocking the Function
Blocking will cause a picked up function to be reset. The tripping function can be blocked externally or inter-
nally by the binary input signal
>Block stage
.
All indications then drop out and the thermal memory is set to the value 0.
Blocking Closure
The signal
Block close
can be used to prevent closure of the protected object at a high thermal load. The
signal is set if the tripping overtemperature is exceeded, and canceled if the temperature falls below the
dropout threshold.
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
Protection and Automation Functions
7.26 Thermal Overload Protection, 3-Phase - Advanced
SIPROTEC 5, High-Voltage Bay Controller, Manual 885
C53000-G5040-C015-9, Edition 11.2017