NOTE: Use the SFT2841, phase protection 50/51-1 tab for a better understanding of what follows.

DEFINITION: the number of functions is referred to as the number of units.


Series 20

Characteristics of 50/51 phase overcurrent protection units:

- the 50/51 function includes 2 units, identified as 50/51-1, 50/51-2

- the units are identical

- each unit can control a different output

- each unit has 2 groups of settings, called set A and set B

- this makes it possible to have 2 different groups of settings per unit

(curve, threshold, delay and other parameters)

- the setting groups may be active separately or together or according to

certain criteria (set up in SFT2841)

- only one output per unit, common to both groups of settings A and B

- each unit has its own protection setting,

- the units are dependent on the common general parameter setting "choice of

setting group A/B".



Series 40

Characteristics of 50/51 phase overcurrent protection units:

- the 50/51 protection function includes 4 units, identified as 1 to 4

- the units are identical

- each unit can control a different output

- the 4 units are grouped in 2 setting ranges, group A and group B

this makes it possible to have a total of 8 different groups of settings

(curve, threshold, delay)

- the setting groups A and B only operate as exclusive OR, i.e. 1 setting

group active at a time

- each unit has its own protection setting



Summary

For the 50/51 protection function:

- Sepam series 20 offers:

2 units with 2 groups of settings each (A and B)

i.e. a total of 4 groups of settings that can operate separately or at the

same time and that activate 2 outputs

- Sepam series 40 offers:

4 units with 2 groups of settings (A and B)

i.e. a total of 8 groups of settings that activate 4 outputs