5. Setting
5. 1. Selection of the switching function and setting range
Selection is done with switch (5), there are 4 functions:
switching function
Operating state: minimum rotational speed reached
The output relay energises when the input frequency
(pulses/min) becomes lower than the set switch point (SP).
If the input frequency becomes higher again, the relay
switches back at the switch point + hysteresis (SP+Hy).
The output relay is de-energised during the start-up delay
and as long as the input frequency is higher than the set
Fault state: below minimum rotational speed
The output relay de-energises when the input frequency
(pulses/min) becomes lower than the set switch point (SP).
If the input frequency becomes higher again, the relay
switches back at the switch point + hysteresis (SP+Hy).
The output relay is energised during the start-up delay
and as long as the input frequency is higher than the
set switch point..
Relay energised = transistor output conductive, relay de-energised = transistor output blocked.
5. 2. Setting of the switch point
Set the switch point with pot (1).
For low switch points the A 300 recognises changes of the actual value
only after a reaction time (which depends on the interval between two
successive pulses). This particularly applies to the switching functions I
and II. For these functions the reaction time is about 12s in case of a
switch point of 5 pulses/min and about 1.2s in case of a switch point of
50 pulses/min.
5. 3. Hysteresis
The hysteresis determines the difference between switch-on point and switch-
off point (switch-on point = the output changes its switching state, switch-off
point = the output switches back to the previous state).
The hysteresis is set to the factor 1.05 (which corresponds to 5% of the switch
point).
With unequal distances between cams different times between two successive
pulses are measured. They can be above or below the switch point so that the
output continuously changes its switching state. By increasing the hysteresis
factor this can be prevented.
/ standstill
switch point.
STANDSTILL MONITOR
switch position
setting range
5...25
pulses/min.
20...100
IV
pulses/min.
5...25
pulses/min.
20...100
III
pulses/min.
A300
I
II
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