Programma EGIL BM-19070, User Manual, Page: 34 / 80

P r o g r a m m a E l e c t r i c A B
Z P - B M 0 1 E R 0 7 A
3 4
E G I L
begin by entering the upper point. The upper point can be
determined in two different ways:
• as a distance below the breaker’s closed
position
• as a position - the position of the moving
contact at the instant of opening
The instant of opening is defined as the last separation of
the main contact in the slowest phase.
The lower point is based on the upper point. It can either
be a distance below the upper point or a time after the
upper point.
Tip
Calculating points, norms and point
adjustments for speed and other param-
eters vary for different breaker types and
must therefore be obtained from the
breaker manufacturer. If you do not have
access to the breaker manufacturer’s
speed calculating points specifications,
as a general rule you can specify the
upper point AT OPN OF MAIN (at main
breaker’s opening) and the lower point
TIME AFTER UPPER: 10 ms (time after
upper point). At 60 Hz, it is 8.33 ms or
0.5 cy. These values are based on an
assumption that the breaker’s speed is
constant in the arcing zone. This occurs
when the contact opens and continues to
the next zero crossing which means at the
most a half period ahead in time (10 ms
at 50 Hz).