Davey Speedman Dual Pump Variable Speed Pump Control System - Manual (Page 37)

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The Jockey pump is typically a smaller auxiliary pump that is outside the flow range of the main pumps. The jockey
pump will turn on when there are no main pumps running and the pressure is below Jockey “Cut-In” Pressure.
The Jockey pump can be set up to “run-on” after the main pumps start but it will eventually be turned off. Once
the main pump/s are running, they will then meet the increased demand. Should the demand then drop to a
point where the main pump become inefficient then the system can be configured to fall back to the Jockey
pump. To do this, set the “Standby Test” in CONFIGURE to “Flow Rate”. The “JP Fallback” option screen can
then be changed from Off to On, this screen is also in CONFIGURE. The correct main pump flow rate has to
be entered or alternatively a flow meter attached, then a minimum flow rate is set in the “Fallback FlowMin”
screen which is in the TUNING menu.
Jockey Pump Mode
The jockey pump can function on any of the settings below:
Main VSD
The Jockey pump will be run from the main VSD. It will try to maintain SET POINT via the response
rate, error correction time and overshoot elimination gain. In this mode the jockey pump will turn off
whenever any main pumps start.
Separate VSD
The Jockey pump will run on its own dedicated VSD. It will try to maintain SET POINT via the response rate,
error correction time and overshoot elimination gain. In this mode when a main pump starts the jockey pump
CAN continue to run at maximum speed until the Jockey Pump “Run on timer” expires.
DOL
The Jockey pump will be run from a DOL contactor. It will run as a switched type pressure control
system with JP Cut In and Cut Out determining when the jockey pump turns on and off . In this mode
when a main pump starts the jockey pump CAN continue to run while the run on timer is active.
JP Cut In Pressure
The “JP Cut In Press” is the Pressure which the pump defined as Jockey pump
will restart. This value cannot be set above the JP Set point and typically it is set
at around 90% of the JP Set point and also above the main pump Cut In Pressure by at least 10%. If set below
the main pump cut in setting the Jockey pump will never operate. The number in brackets on the RHS of the
bottom line is the actual pressure setting based on the percentage setting.
JP Set Point / Cut Out
The pressure the Jockey Pump will maintain. This value will be constrained by
HIGH PRESSURE LIMIT.
This screen will appear as “JP Cut Out Press” when Jockey
Pump Mode is set as DOL.
JP Flow Rate
The jockey pump is typically much smaller than the main pumps therefore the
appropriate pump flow rate needs to be entered to obtain a more accurate calculated
flow rate and min flow requirements.
JP Response Rate
Set the reaction rate (responsiveness) of the system. This value is specific to the
jockey pump if the Jockey Pump is running on the VSD.
It is expressed as a percentage ranging from 0.1 – 100.0
0.1 is the slowest response and 100.0 the fastest.
Jockey Pump
Mode
JP Cut In Press
XX % (123)
JP Set Point
XXXX
JP Cut Out Press
XXXX
JP Flow Rate
XX/Sec
JP Response Rate
XX.X %