GE F650 Instruction Manual page 202

5 SETTINGS
5.4.3.4 THERMAL MODEL ELEMENT (49)
Thermal model is a protection element that calculates the thermal heating generated as a result of the flowing current, and
prevents this heating from causing damage to the protected equipment. In order to calculate the tripping time, the following
equation is used:
Where,
τ is the heating/cooling time constant.
I' is the ratio current/pickup
Table 5–45: THERMAL MODEL ELEMENT SETTINGS
SETPOINT > PROTECTION ELEMENTS > PHASE CURRENT > THERMAL MODEL >
THERMAL MODEL 1> THERMAL MODEL 2 > THERMAL MODEL 3
SETTING DESCRIPTION
Function permission
Heating time constant
Cooling time constant
Pickup level
Alarm level
Snapshot event generation
The cooling constant is given in times the heating constant.
The snapshot event setting enables or disables the snapshot event generation for the thermal model elements.
GEK-106310AB
NAME DEFAULT
VALUE
Function DISABLED
Heat Time Constant 6.0
Cool Time Constant 2.00
Pickup Level 1.00
Alarm Level 80.0
Snapshot Events ENABLED
F650 Digital Bay Controller
5.4 PROTECTION ELEMENTS
STEP RANGE
N/A [DISABLED – ENABLED]
0.1 min [3.0 : 600.0]
0.01 times Heat Time [1.00 : 6.00]
0.01 A [0.05 : 160.00]
0.1 % [1.0 : 110.0]
N/A [DISABLED – ENABLED]
5
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