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