DAB PUMPS PWM 201, Instruction For Installation And Maintenance

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2. If FZ is too low, the electropump might never stop even in the absence of flow, or with very low flows. This situation could
lead to damage of the electropump due to overheating.
Since the zero flow frequency FZ may vary as the Setpoint varies, it is important that
: .
1. Whenever the Setpoint is changed you check that the set value of FZ is adequate for the new Setpoint.
The auxiliary set points are disabled if the flow sensor is not used (FI=0) and when FZ is used in minimum frequency
mode (FZ ≠ 0) .
CAUTION: the minimum frequency mode is the only operating mode without flow sensor admitted for multiple inverter systems.
Self-adaptive mode: this mode consists of a particular and efficient self-adaptive algorithm which allows operation in nearly all cases
without any problem. The algorithm acquires information and updates the relative parameters during operation. To ensure optimal
operation, there should not be any substantial periodic variations on the hydraulic system, which cause significant differences
between values (such as solenoid valves that exchange hydraulic sectors with very different characteristics), as the algorithm adapts
only to one of these and cannot provide the expected results as soon as switching is performed. On the other hand, if the system
remains with similar characteristics (elasticity length and minimum required flow rate) there are no problems.
On each restart or reset of the unit, the self-learnt values are reset, and therefore a specific time interval is required to self-adapt.
The algorithm used, measures the various sensitive parameters and analyses the unit status to detect the presence and entity of the
flow. For this reason, and to avoid false errors, correct parameter settings are fundamental, and in particular:
•
Ensure that there are no system oscillations during regulation (if this occurs, adjust parameters GP and GI section 6.6.4
and 6.6.5)
•
Enter the correct rated current setting RC
• Set an adequate minimum flow FT
•
Set the correct minimum frequency FL
•
Set the correct direction of rotation
WARNING: the self-adaptive mode is not allowed on multi-inverter systems.
IMPORTANT: In both operating modes the system is able to detect the lack of water by measuring the current absorbed by the pump
and comparing it with the parameter RC (see 6.5.1). If the maximum operating frequency FS is set with a value that does not enable
absorption of a value close to the current under full load of the pump, false water failure errors (BL) may occur. In this case, remedy
the situation as follows: turn on the utilities to reach the frequency FS and at this value, check pump absorption (easily seen on
phase current parameter C1 in the User menu), then set the current value reading on RC.
6.5.9.1.1 Fast self-learning method for auto-adaptive mode
The self-learning algorithm is adaptable to various systems automatically on acquisition of information on the type of system.
The system set-up process can be shortened by using the quick learning the procedure:
1) Turn on the unit or, if already powered, press MODE SET + - simultaneously for 2 seconds to generate a reset.
2) Enter the Installer menu (MODE SET -) set FI to 0 (no flow sensor) then in the same menu go to item FT.
3) Turn on a utility and run the pump.
4) Slowly turn off the utility to reach minimum flow (utility closed) and when this value stabilises, note the corresponding
frequency.
5) Wait 1-2 minutes for the simulated flow reading; this is confirmed by shutdown of the motor.
6) Turn on a utility to achieve a frequency that is 2 – 5 [Hz] greater than the previous frequency reading, and then wait
1-2 minutes for another shutdown.
IMPORTANT: the method is only effective if, while gradually closing the utility in point 4) the frequency remains at a fixed
value through to reading of the flow VF. It should not be considered a valid procedure if, after closure, frequency reaches
0 [Hz]; in this case the operations from point 3 must be repeated; otherwise leave the unit to self-learn for the time interval
specified above.
6.5.9.2 Operation with specific pre-defined flow sensor
This applies both to single and multiple sensors.
Use of the flow sensor enables effective measurement of the flow and the possibility of operation in special applications.