Inputs/Outputs - GE T60 Instruction Manual

INPUTS/OUTPUTS

I is the measured overload RMS current at index n
n
E is the accumulated energy at index n
n
E is the accumulated energy at index n – 1
n – 1
The thermal overload protection element removes the
emergency, the thermal memory and
All calculations are performed per phase. If the accumulated energy reaches value 1 in any phase, the thermal overload
protection element operates and only resets when energy is less than 0.05 in all three phases.
Table 5-43: Typical time constants
Protected equipment
Capacitor bank
Overhead line
Air-core reactor
Busbar
Underground cable
The figure shows the logic for the thermal overload protection element.
5
5.9 Inputs/outputs
5.9.1 Contact inputs
SETTINGS  INPUTS/OUTPUTS  CONTACT INPUTS
 CONTACT INPUTS

5-342
THERMAL PROT 1 OP
THERMAL PROT 1 OP
Time constant Minimum reset time
10 minutes 30 minutes
10 minutes 20 minutes
40 minutes 30 minutes
60 minutes 20 minutes
20 to 60 minutes 60 minutes
Figure 5-202: Thermal overload protection logic
 CONTACT INPUT H5a


output operand when E < 0.05. In case of
output operand can be reset using
T60 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
setting.
THERM PROT 1 RESET