Siemens SITRANS LUT400, Operating Instructions Manual

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A5E33329501 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS Page 91
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Saving energy
Pumps can use different setpoints at different times of the day to account for variable
energy costs.
The following example illustrates high energy cost usage reduction and/or elimination by
using the SITRANS LUT400 Energy Savings function on a wet well (pump down
application) using pump 1.
Pre-requisite: enable Energy Savings function (set 2.7.2.2.1. Enable
= Enabled)
Generally, you would cascade the timing of the pump downs so that the wells farthest
from the treatment facility would begin first and the entire system would push material
through during the low cost period.
Normal Operation
Uses the standard ON and OFF setpoints (
2.7.1.6.
ON Setpoint Pump 1 / 2.7.1.7. OFF Setpoint Pump 1 ).
Energy cost is at minimum.
2.7.2.2.2. Peak Lead Time
= 60 minutes.
Pumps down the wet well regardless of the pump
ON Setpoints. This ensures that the wet well
starts the high cost period at the
2.7.1.7. OFF
Setpoint Pump 1
. Energy cost is at minimum.
2.7.2.2.3. Peak 1 Start Time
= 17:30.
Starts using the energy savings setpoints
(
2.7.2.2.13. Peak ON Setpoint Pump 1
and
2.7.2.2.14.
Peak OFF Setpoint Pump 1
).
Energy cost is at maximum.
2.7.2.2.4. Peak 1 End Time = 21:30.
Returns to normal setpoints ( 2.7.1.6. ON Setpoint
Pump 1 / 2.7.1.7. OFF Setpoint Pump 1 ).
Energy cost returns to minimum.
Note:
When the Peak ON Setpoint is not reached, no energy is used during the high
cost period. If the Peak ON Setpoint is reached, the Wet Well is only pumped down to
6 m, thereby minimizing high cost energy usage.
Parameter Value Description
2.7.2.2.1. Enable
Enabled Enables Energy Savings function
2.7.2.2.3. Peak 1 Start Time
17:30 Starts the first high cost period at 5:30 pm
2.7.2.2.4. Peak 1 End Time
21:30 Ends the first high cost period at 9:30 pm
2.7.2.2.2. Peak Lead Time
00:60
Sets the pump down to happen 60 minutes
before the high cost period
2.7.2.2.13. Peak ON Setpoint
Pump 1
9
Sets the high cost ON setpoint at process level
of 9 m
2.7.2.2.14. Peak OFF Setpoint
Pump 1
6
Sets the high cost OFF setpoint at process level
of 6 m
8 m (ON setpt.)
2 m (OFF setpt.)
8 m (ON setpt.)
2 m (OFF setpt.)
9 m (Peak ON)
8 m (ON setpt.)
6 m (Peak OFF)
2 m (OFF setpt.)
9 m (Peak ON)
8 m (ON setpt.)
2 m (OFF setpt.)
6 m (Peak OFF)
15:30
(3:30 pm)
16:30
(4:30 pm)
17:30
(5:30 pm)
21:30
(9:30 pm)