70101417
2018-12
Universal Transmitter Power Supply KF**-CRG2-(Ex)1.D
Editing Device Data: Relays
26
7.4.2 Trip and Hysteresis
When entering the values for
Trip
and
Hysteresis
please note:
• Both values are to be entered in the units, which were selected under
Units
• You can enter values
between 0 mA and 24 mA and
between the converted values of these limits in the selected units; for conversion using the
parameters
Zero point
and
Conversion factor
• The hysteresis must be selected as > 1 % of the trip point to prevent the relay from vibrating.
• As the representation of the operating behaviour in section 7.4.1 shows, the following must apply:
for the switching direction
Max
: Trip point - Hysteresis
0
for the switching direction
Min
: Trip point + Hysteresis
upper limit trip point
These input limits are automatically preset by the device.
7.4.3 Alarm Freeze
The
Alarm freeze
helps you to avoid that short-term trip value overranges are not noticed by the
operating staff.
If
Alarm freeze On
has been selected, the new state is maintained after the relay switching until the ESC
key is pressed or the device is restarted. These actions reset the relay, except for a trip value overrange.
7.4.4 Delay
If you set a time > 0 sec, you prevent short-time trip value overranges of the trip value from triggering
an alarm.
• The relay only switches if the trip point is exceeded/fallen short of for a period that is longer than the
delay time.
• The relay only switches back if the trip point -/+ hysteresis is fallen short of/exceeded for a period
that is longer than the delay time.
• If the trip point is exceeded/fallen short of for a short time, this does not have any effects.
• You can adjust the delay time from 0 s to 250 s.
