SEPAM Trip Curves: Type 1 versus Type 1.2
Issue
User would like to understand the difference in tripping characteristics between Type 1 and Type 1.2 trip curves on SEPAM relays.
Product
SEPAM Series 20
SEPAM Series 40
SEPAM Series 80
Environment
SFT2841 configuration software
Cause
Confusion arises due to the availability of two curve types (Type 1 and Type 1.2) that appear similar but have different pickup conditions, which affects protection coordination and relay response.
Resolution
SEPAM relays offer two selectable trip curve types: Type 1 and Type 1.2.
- Type 1 Curve:
- Pickup occurs when the measured current equals the relay threshold setting
- Condition: I = Is
- Type 1.2 Curve:
- Pickup occurs when the measured current reaches 1.2 times the relay threshold setting
- Condition: I = 1.2 × Is
- After pickup, it follows the same tripping characteristics as the standard Type 1 (IEC) curve
Key difference:
- The only distinction between the two curves is the pickup level
- Once pickup is reached, both curves behave identically in terms of time-current characteristics
For further analysis and visualization:
- Refer to the available trip curve calculators for SEPAM and MiCOM relays
- Review the comparison charts showing Type 1 vs Type 1.2 characteristics