Sterlco SF1000 Gravimetric Additive Feeder - Manual (Page 21)

21
4.7 Failure alarms
Once there is an Alarm condition, it is indicated by
the "alarm" mark in the left corner of the Main
Screen
Any time when a new alarm situation occurs, the
Alarm Screen is displayed, indicating which alarms
are active at present moment.
As long as an Alarm situation exists, the Alarm
Output (J2) is activated (see 4.7.5)
You can enter the Alarm Screen any time by pressing
the key
Available alarms are:
4.7
.1 “Fill” Alarm
Under normal conditions (MB%>0), once the weight of the MB/additive in the hopper
decreases below a Minimum Fill low level, the controller instructs the Venturi loader to start
refilling the hopper. The refilling operation will continue either until the material weight
reaches the Maximum Filling high level, or until 60 seconds have passed (whichever comes
first).
If, for some reason, the MB/Additive weight in the
hopper stays under the low limit value for more than
120 seconds, despite the filling operation, an “Alarm”
screen will be displayed, i
ndicating a “No Fill”
situation.
Check the material in the MB/Additive container and/or proper operation of the Venturi loader
and the vacuum supply.
 Press to return to Main screen
4.7
.2 “Over/Under Speed (dose)” Alarms
These alarms appear once the required motor speed (rpm) is not within the motor speed
(rpm) range (i.e. either too high or too low) for the selected screw and the desired flow.
The maximum and minimum possible dosing rates for a specific material and screw are
restricted by the motor's maximum and minimum possible current (rpm) range.
If the process data (batch weight, MB desired % and feeding time) requires a motor's current
(rpm) that is either above its maximum possible rate (100%), or below its minimum possible
rate (2.5%), the actual flow will be restricted to the motor's limitations (either 100% or 2.5%)
and the "Alarm" screen will be displayed accordingly.
If the process conditions require a very high flow,
above the motor's speed limit, an Over-Speed alarm
screen will be displayed, warning that the motor has
reached its maximum speed (100%) and the actual
flow is under the desired flow.