9 . 1 C u r r e n t s e n s i n g r e l a y
( c o n t i n u e d )
A simple way to find the correct limit value for your granulator is to have the gran-
ulator motor in normal operation, then turn the knob back from 100% until the
relay drops. Then turn the knob forwards until the limit is just above this level.
The lower % setting, “B”, is used to set the hysteresis-in level. The level after
alarm when the relay should re-start the feed equipment/conveyor. If the hysteresis
knob is set at 20%, the relay will re-start the feed equipment when the current has
gone down to the limit value plus the hysteresis value of 20%.
“T1” is a time delay, which determines the time that the granulator motor can
exceed the set limit value before the relay drops.
“T2” is a time delay, which is only activated when the granulator starts. This time
delay prevents the relay from dropping when the granulator is started and when the
current usually exceeds the set limit value for the relay.
Function setting with or without memory. When you use the “With memory” set-
ting, the relay does not re-start the feed equipment of the granulator when the cur-
rent has fallen to the limit value plus the hysteresis value. The relay memory set-
ting must be re-set manually first.
The default setting of this function choice is “Without memory”.
Function selection, with under-current or excess current. We measure the current
used by the granulator, so the selector should be in the “Excess current” position.
Default setting for this granulator:
Granulator motor, rated current:
. . . . . . . . .
. . . . . . . . . =
A
(recommended fuse in mains min 1,5 x granulator motor rated current)
Current transformer:
. . . . . . . . . . /1A
Time delay reaction time T1:
3.0 sec.
other value: . . . . . . . . . .
Time delay at start T2:
0.1 sec.
other value: . . . . . . . . . .
Limit values:
% . . . . . . . .
= . . . . . . . . .A
Hysteresis:
% . . . . . . . .
= . . . . . . . . .A
Function choice:
with memory
without memory
under-current
excess current
9 - 4
l W i r i n g D i a g r a m