TECO F33 Series, Instruction Manual, Page: 112 / 192

Functional Description 109
Fig. 95 Transition speed start
Fig. 96 Effect of transition speed
Settle Time Stop [39F]
The settle stop allows the process to settle after a
pump is switched off before the pump control contin-
ues. If an additional pump is stopped D.O.L. (Direct On
Line) or Y/
,
the flow or pressure can still fluctuate
due to the 'rough' start/stop method. This could cause
unnecessary starting and stopping of additional
pumps.
During the Settle stop:
• PID controller is off.
•
the speed is kept at a fixed level after stopping a
pump
Communication information
Transition Speed Stop [39G]
The transition speed stop is used to minimize a flow/
pressure overshoot when shutting down an additional
pump. The setting depends on the dynamics of both
the master drive and the additional drives.
In general:
• If the additional pump has 'slow' start/stop dynam-
ics, then a higher transition speed should be used.
•
If the additional pump has 'fast' start/stop dynam-
ics, then a lower transition speed should be used
.
Communication information
Example
Max Speed = 1500 rpm
Min Speed = 200 rpm
TransS Start = 60%
When less additional pumps are needed, the speed will
be controlled up to min speed + (60% x (1500 rpm -
200 rpm)) = 200 rpm + 780 rpm = 980 rpm. When this
speed is reached, the additional pump with the highest
run time hours will be switched off.
Fig. 97 Transition speed stop
Default: 0 s
Range: 0–999 s
Modbus Instance no/DeviceNet no: 43175
Profibus slot/index 169/79
Fieldbus format Long, 1=1 s
Modbus format EInt
(NG_50-PC-16_1)
Speed
Actual
Trans
Min
Switch on
procedure starts
Additional pump
Master pump
Flow/Pressure
Actual start
command of next
pump (RELAY)
Flow/Pressure
Transition speed
decreases overshoot
Time
Δ
A
39F Settle Stop
Stp 0s
Default: 60%
Range: 0-100% of total min speed to max speed
Modbus Instance no/DeviceNet no: 43176
Profibus slot/index 169/80
Fieldbus format Long, 1=1%
Modbus format EInt
39G TransS Stop
Stp 60%
A
Speed
Max
Trans
Actual
Min
Actual shut down of pump
Master pump
Switch off procedure starts
Additional pump
Flow/Pressure