YASKAWA iQpump Manual Supplement page 34

10 iQpump MEMOBUS/Network Operation
New Lead Drive Selection: Stop History
Overview
Many irrigation pumping skids consist of a PM pump (Pressure Maintenance) and typically two (2) larger booster pumps
to maintain high flow peak demands.
In many cases depending on the number of irrigation zones in combination with the type of sprinkler heads used, the flow
demand fluctuates and may not require the use of both larger booster pumps at the same time until higher flow rates are
required.
The iQpump Controller "Run Stop" history ensures that both booster pumps alternate each run cycle.
Parameters
P9-01 Lead Drive Selection
Selects the detection method for staging a new pump.
Setting
Next Available
0
Select next available drive on the network as the new lead drive.
Lowest Runtime (factory default)
1
Select the iQpump Controller with the lowest runtime as the new lead drive.
Stop History
2
Select the iQpump that had been stopped the longest time.
Note: This new lead drive selection also applies to Alternation (P9-03 > 0) and will use the Stop History list when finding the alternate
drive.
System Example: Triplex Irrigation Booster System-Using Stop History
Overview
A typical pump system operates as described below:
When pressure is dropping, the PM Pump (if installed) will attempt to return the system pressure to the desired setpoint
level. If the PM Pump is not able to return the system to the setpoint pressure, typically due to a greater flow demand, the
first booster pump (1) will be called to start.
The iQpump Controller will speed up or slow down the pump as needed to maintain the system pressure. When flow
decreases and the pump system is no longer required to run, the system will go to sleep waiting for the pressure to drop.
On the next run cycle the PM pump will start up again, and instead of running booster pump #1, booster pump #2 is
started, since booster #1 ran during the last cycle.
This method ensures that during normal operation both booster pumps will operate evenly as lead or lag pumps each run
cycle.
Detailed Description
Triplex irrigation booster system consisting of one PM Pump (pressure maintenance) and two larger booster pumps of the
same horsepower. The customer would like to ensure that the PM Pump is also the lead pump to recharge the system
during low flow usage, but during high demands the booster pumps alternate on each run cycle or if required will both run
to support very high flow demands.
• Jockey/PM Pump will also be lead to start.
• Jockey/PM Pump will stage booster pump 1 or 2 and stay running for 20 seconds and then shut off.
• Booster pump 1 will run system and if required, call for booster pump 2 or vice versa.
• On sleep mode, the lead drive for starting will swap back to Jockey/PM Pump.
• System setpoint 100 psi.
• Pressure drop of 10 psi will start the Jockey pump.
• All drives have individual transducers rated 200 psi maximum, but if there is a transducer failure, switch to network.
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Description
YASKAWA TM.iQp.10 iQpump Technical Manual Supplement