Franklin Electric CERUS X-DRIVE CXD-003A-4V, Installation And Operation Manual

Page: 102 / 252

ADVANCED APPLICATION OPTIONS
Duplex Pump Configurations
102
Duplex Pump Configurations
Jockey Pump Control
A Jockey pump system consists of high HP Main pump and low HP Jockey pump. The VFD that controls the
main pump provides constant pressure control with PID loop for that pump and start signal via communica
-
tion or relay output for Jockey pump. The jockey pump can be controlled by starter, soft-starter or another
VFD.
The jockey will be started by the main VFD relay output (RA1, RA2, or RA3) if a relay output is set to
48_Jockey Pump [IO–47] to [IO-49] , or through RS-485 communications if it is controlled by another VFD. Refer
to “Multi-Drive Configurations” on page 107 for more information about controlling a jockey with a separate
VFD.
1.
When the system is in Auto mode with pressure equal to or less than
Wake-Up Level [SET-31]
(from Sleep
feature), the main pump will start first and will maintain system pressure. Then:
•
If demand drops low, jockey pump will start, and main pump will stop.
• If demand becomes highest, jockey will start and run together with main pump.
2. When the system is in Auto mode with pressure greater than Wake-Up Level [SET-31] but less than J-Start
Press [ADV–49]
, jockey will start first.
3. When the system is in Auto mode with pressure greater than J-Start Press [ADV–49] , both jockey and main
pumps will be off.
At low demand, when the main pump’s speed is less than Main Stop Freq [ADV–51] and system pressure is at
Setpoint for
J-Start Delay [ADV–52]
, jockey will start and, after a two second delay, the main pump will stop. The
VFD uses J-Start Press [ADV–49] and S-Boost Value [SET-29] (Sleep feature) for jockey start/stop control.
During Jockey pump run, if system pressure becomes:
1.
Equal to or greater than S-Boost Value [SET-29] , jockey pump will stop.
2. Less than
Wakeup Level Wake-Up Level [SET-31]
for two seconds, the main pump will start and after
J-Start
Delay [ADV-52] system pressure is:
• Below or at Setpoint and main VFD speed is greater than
J-Start Freq [ADV-50]
for two seconds,
jockey will continue to run helping main pump to maintain pressure setpoint.
• At or above Setpoint and main VFD speed is less than
J-Start Freq [ADV–50]
and greater than
Main Stop
Freq [ADV-51] for two seconds, jockey will stop, and main pump alone will maintain pressure set -
point.
• At or above Setpoint and less than Boost Pressure and main VFD speed is less than Main Stop Freq
[ADV–51]
for
Main Stop Delay [ADV-53]
, main pump will stop, and jockey will continue to run until pres -
sure is greater than S-Boost Value [SET-29] .
• Equal to or greater than
S-Boost Value [SET-29]
for two seconds, both main and jockey pumps will
stop.
To enable jockey pump control, adjust the following parameters:
Jockey Mode [ADV–48]: This setting enables or disables the feature.
J-Start Press [ADV–49]: Pressure setpoint for jockey start when all other conditions have been met. Range
= 10% of PID Setpoint [SET-21] to PID Setpoint [SET-21] . Default = 54 PSI.
J-Start Freq [ADV–50]: Jockey starts when main pump is running above this frequency and all other condi -
tions have been met. Range = PID Lo Hz Limit [SET–22] to PID Lo Hz Limit [SET–22] .
Main Stop Freq [ADV–51]: Main pump will stop if it runs below this frequency. Jockey will continue to run
until pressure settings have been met. Range = PID Lo Hz Limit [SET–22] to PID Lo Hz Limit [SET–22] .
J-Start Delay [ADV–52]: Time delay before jockey starts when all conditions have been met. Range = 1 to
6000 seconds. Default = 20 sec.
Main Stop Delay [ADV–53]: Time delay before main pump stops when all conditions have been met. Range
= 1 to 6000 sec. Default = 5 sec.