Service Ratio Duty Backup - Siemens HydroRanger 200 HMI Operating Instructions Manual

Service Ratio Duty Backup

2.8.1.4. Relay Function = Service Ratio Duty Backup selects the lead pump based on the
number of hours each pump has run and the specified ratios that each pump requires.
Only one pump can run at a time.
This algorithm is the same as Service Ratio Duty Assist except that it will run only one
pump at a time. When the next pump in the sequence starts, the previous pump stops.
First In First Out
2.8.1.4. Relay Function = First In First Out selects the lead pump based on the Alternate
duty, but uses staggered OFF setpoints and shuts down pumps based on the first in, first
out rule.
This algorithm starts pumps in the same way as Alternate Duty Assist but uses staggered
OFF setpoints to shut the pumps down. When the first OFF setpoint is reached, the FIFO
rule shuts down the first pump started. For example: pumps started in sequence 2,3,1
would be shut down in sequence 2,3, 1 .
Pump by Rate
Pump by Rate (2.8.1.8.) starts pumps until the level is changing at the rate specified in
2.3.9. Filling Indicator or 2.3.10. Emptying Indicator.
Pumping costs can be less because only the highest ON setpoint needs to be
programmed and this results in a lower difference in Head to the next wet well which, in
turn, results in less energy being used to pump out the well.
Other pump controls
There are a number of other controls available to modify pump behavior.
Pump Run-ON
2.8.2.7. 1 . Run-ON Interval
(
Extends the RUN period for a pump based on a set time interval. This allows for the wet
well to be pumped lower than usual, and reduces sludge build-up on the well bottom.
Wall Cling Reduction
2.8.2.6.2. Level Setpoint Variation
(
Varies the ON and OFF setpoints to keep a fat ring from forming around the walls of the
wet well.
Pump Group
2.8.2.2. Pump Group
(
Allows for two different Alternate Duty Assist or Alternate Duty Backup pump groups in
the same application.
Flush Device
2.10.3.2. Flush Pump
(
Operates a flush valve or special flush device based on the number of pump starts,
usually to aerate wet well wastewater.
Page 252 HydroRanger 200 HMI – OPERATING INSTRUCTIONS
2.8.2.7.3. Run-ON Duration
,
)
)
2.10.3.3. Flush Cycles
, ,
)
2. 1 0.3.4. Flush Interval
,
2.10.3.5. Flush Duration
A5E36281317
)