salmson LRE Installation Et Mise En Service page 79

Parallel operation
H
H
max
H
s
s
H
min
Fig. 14: p-c control (parallel operation)
H
H
H
max
H
s
H
min
Fig. 15: p-v control (parallel operation)
6.3.2 Behaviour in dual pump operation
Pump cycling
Δp
Pump 1
Fig. 16: Pump cycling
Behaviour of the inputs and outputs
Installation and operating instructions LRE, JRE
Q
Q
Q
Pump 2
• Pump 1 turns (black line)
• Pump 2 is switched on at minimum speed and soon afterwards
• Pump 1 is switched off
t
• Pump 2 continues to run until the next pump cycling
• At the master: acts on the whole unit
• Set at the master (menu <5.1.7.0>): depending on the setting in menu
• Set at the slave: acts only on the slave
In the partial load range, the hydraulic output is provided at the
beginning by one pump. The second pump will be switched on when
it is most effective to do this, i.e. when the total power consumptions
P of both pumps in the partial load range is less than the power con-
1
sumption P of one pump. Both pumps will then be simultaneously
1
adjusted upwards to the maximum speed. (Fig. 14 and 15).
In manual control mode, both pumps always run synchronously.
Parallel operation of two pumps is only possible with two identical
pump types.
See chapter 6.4 "Other functions" on page 71.
In dual pump operation, a pump cycling occurs periodically (the period
can be set; factory setting: 24 h).
Pump cycling can be triggered:
• Internally, time-controlled (menu <5.1.3.2> + <5.1.3.3>)
• Externally (menu <5.1.3.2>) by a positive edge at the "AUX" contact
(See Fig. 23)
• Manually, (menu <5.1.3.1>)
Manual or external pump cycling is possible five seconds after the last
pump cycling, at the earliest.
Activation of external pump cycling simultaneously deactivates
internal time-controlled pump cycling.
Pump cycling can be described schematically as follows (see also
Fig. 16):
reaches the setpoint (grey line)
NOTE:
In manual control mode, a slight increase in flow can be expected.
Pump cycling is depending on the ramp time and generally lasts 2 s. In
auto control, there may be minor fluctuations in the delivery head.
However, pump 1 adjusts itself to the changed conditions. Pump
cycling is dependent on the ramp time and generally lasts 4 s.
Actual value input In1 setpoint input In2
"External off":
<5.1.7.0>, acts only on the master or on the master and the slave
English
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