Function Block - ABB Relion Technical Manual

1MRK 502 048-UUS A
8.4.3
8.4.4
Technical manual
The thermal overload protection estimates the internal heat content of the transformer/
generator (temperature) continuously. This estimation is made by using a thermal model
of the transformer/generator with two time constants, which is based on current
measurement.
Two warning pickup levels are available. This enables actions in the power system to be
done before dangerous temperatures are reached. If the temperature continues to increase
to the trip value, the protection initiates a trip of the protected transformer/generator.
Estimated time to trip before operation is presented.

Function block

TRPTTR (49)
I3P* TRIP
BLOCK PICKUP
COOLING ALARM1
RESET ALARM2
LOCKOUT
WARNING
ANSI08000037-1-en.vsd
ANSI08000037 V1 EN
Figure 106: TRPTTR (49) function block
Signals
TRPTTR is not provided with external temperature sensor in first release
of 650 series. The only input that influences the temperature measurement
is the binary input COOLING.
Table 102: TRPTTR (49) Input signals
Name Type
I3P GROUP
SIGNAL
BLOCK BOOLEAN
COOLING BOOLEAN
RESET BOOLEAN
Default Description
- Three phase group signal for current input
0 Block of function
0 Cooling input changes IBase setting and time constant
0 Reset of function
Section 8
Current protection
235