ADVANCED APPLICATION OPTIONS
Multi-Drive Feature (Mobile App Only)
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The Lead becomes active when in Auto mode, with its own run command, and a run command from
the Master.
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Assignment of the Lead drive can be optionally assigned to other drives on a rotating basis.
IMPORTANT: Since the Lead can change, each VFD needs its own feedback sensor; or, the system could
have a single sensor with analog splitters to feed each drive. Each VFD needs to be set to the same set-
point. If a change in setpoint is needed, the setting needs to be updated on all the drives.
L L a a g g : : A Lag drive becomes active when the Master determines that the setpoint cannot be met by the
Lead.
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Before a Lag drive can start, it must be in Auto mode, with its own run command, and a run com-
mand from the Master.
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Lag Speed sets the Lag drive to run either on its own PID or at a fixed frequency. If a Lag drive is al-
ternated to become a Lead, it automatically switches to PID mode.
NOTE: If a Lag is operating in PID mode, it could possibly run at a higher frequency than the Lead at
times as the overall system balances itself.
Sequence Assignment
The system has the capability to rotate assigned drive roles through the network based on the parameter
setting Alternation. There are two possible scenarios:
A A l l t t e e r r n n a a t t i i o o n n – – D D i i s s a a b b l l e e d d : : This setting might be appropriate when the system primarily operates at a low
flow rate and uses the Lag pumps as backups when needed.
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In this case, the Lead pump could be sized for efficiency at a lower flow rate and would always be
the first to start.
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The Lead/Master would regulate the pressure of the system using its own PID sensor.
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The Lag pumps could be sized differently and could either use their own PID or be set to run at a
specific frequency.
A A l l t t e e r r n n a a t t i i o o n n – – T T i i m m e e r r : : This scenario might be used to rotate the Lead role to distribute wear on a system
with continuous operation.
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In this case, the system roles would be rotated after running for a specific time, set in Alternation
Timer.
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In addition to balancing usage, this practice would help ensure the proper functioning of Lag units
that might otherwise be idle for extended periods.
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The best practice would be to size and program all pumps/drives the same.
In all cases, the Master will be the drive with the lowest drive ID number (i.e. VFD 1).
If the Master faults, it is switched to O O F F F F or to H H A A N N D D Mode. The Master role is then shifted to the drive
with the next lowest ID. If there is a break in communication, the lowest drive ID on any remaining func-
tional network is assigned the Master role.
E E x x a a m m p p l l e e R R o o t t a a t t i i o o n n P P a a t t t t e e r r n n : :
Event
System Start
First Alteration
Second Alteration
VFD 1 Fault
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VFD 1
VFD 2
Master/Lead
Lag 1
Master/Lag 4
Lead
Master/Lag 3
Lag 4
Not Ready
Master/Lag 3
VFD 3
VFD 4
Lag 2
Lag 3
Lag 1
Lag 2
Lag 1
Lead
Lag 1
Lead
VFD 5
Lag 4
Lag 3
Lag 2
Lag 2