Delta OHM HD2817T Series, Manual

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2) The trigger threshold Act above (high tripping point) : when the measurement increases ,
it represents the threshold ( ACTIVE ABOVE in the menu) that shifts the relay from de-
energised to energised when exceeded. The contacts 5-6 and 8-9 will close, the contacts
6-7 and 9-10 will open. The trigger threshold can be disabled.
3) The trigger threshold
Act below (low tripping point) : when the measurement decreases ,
it represents the threshold ( ACTIVE BELOW in the menu) that shifts the relay from de-
energised to energised when exceeded. The contacts 5-6 and 8-9 will close, the contacts
6-7 and 9-10 will open. The trigger threshold can be disabled.
4) The hysteresis value applies to both thresholds defined above (
Hysteresis in the menu).
The hysteresis prevents the relay from toggling between the states when the
measurement comes close to the set threshold. The relay is energised when the
measurement reaches one of the two trigger thresholds. When the measurement returns
toward the value of the set threshold, the relay does not shift on the threshold value but
on the threshold
hysteresis value .
Notes :
a) You can disable the hysteresis, but we recommend to maintain it to avoid any
malfunctioning near the relay trigger point.
b) The hysteresis width should be lesser than the difference between the two trigger
thresholds Act above (high threshold) and Act below (low threshold).
c) If the Act above (high) threshold is lesser than the Act below (low) threshold, the
hysteresis works contrariwise: the relay de-energises when the measurement exceeds
the threshold and not, as in the opposite case, the threshold the hysteresis.
5) Behaviour of the relay if the associate physical quantity goes in error (
ON ERROR in the
menu).
a) The error can occur when the measurement exceeds the functioning limits indicated in
the technical information,
b) When the probe becomes faulty or gets disconnected.
c) Selecting “
ON ERROR = Inactive ”, in case of error of the controlled quantity, the relay
de-energises.
d) Selecting “
ON ERROR = Active ”, in case of error of the controlled quantity, the relay
energises.