Calpeda I-MAT Serie Instrucciones De Uso página 32

9.2.2. Constant pressure mode with 2 pressure
transducers (differential mode)
If it is required to use a differential pressure
feedback, between delivery and suction of the pump
by using 2 transducers it's necessary to connect
EN
the first transducer and the second transducer as
shown in section 6.7.
Parameters to programm or check (recommended
sequence):
Par.
Description
AP01
Maximum pump pressure
AP02
Primary transducer supply
Primary transducer
AP03
measuring unit
Primary transducer
AP04
minimum value
Primary transducer
AP05
maximum value
Secondary transducer
AP06
supply
Secondary transducer
AP07
measuring unit
Secondary transducer
AP08
minimum value
Secondary transducer
AP09
maximum value
AP10
Secondary transducer mode
UP02 Nominal pump current
UP03
Nominal pump frequency
UP05 Operating mode
UP06
Primary set-point
To ensure the system works properly, the
primary transducer (B1-B4 clamps) must be
always connected to the delivery pipe, and
the secondary transducer (B5-B8 clamps)
must be always connected to the suction
pipe.
9.2.3. Minimum run frequency and pre-pause
frequency settings
The frequency converter is equipped with an
automatic stop system in case of low water. In
the case where the system does not guarantee
the correct stop of the pump, it is possible to set
manually the following values:
Frequency before stop
Minimum run frequency
In order to manually set these parameters it is
necessary to change the value of parameter AP17
from "Auto" to "Man". Then the pre-pause frequency
values (PC02 and PC04 parameters) and the
minimum frequency values (PC01 and PC03
parameters), must be set using the calculation
formulas described in the next section.
9.2.4. Frequency before stop and minimum run
frequency calculation formulas
Adjusting the pre-pause frequency (PC02 and
PC04 parameters) allows you to properly stop the
pump when the water demand is low and the pump
operation is no longer required (e.g. a leakage or a
small flow of a few liter per minute).
In this case the pump must be stopped for some
Page 32 / 144
seconds and the flow is guaranteed by the reserve
stored in the vessel.
The frequency before stop Hz P can be calculated
as follows:
50 Hz pumps
60 Hz pumps
where: - H set is the working pressure in bar
Suggested value
based on pump type
(*) For the maximum pump pressure it's required:
data sheet
transducer
For the pumps operating with suction lift subtract
1 [bar]
the suction lift value (in bar).
For the pumps installed with suction positive add
data sheet
transducer
the positive suction head value (in bar).
The minimum run frequency (PC01 and PC03
data sheet
transducer
parameters) must be set 6-7 Hz lower than the
data sheet frequency before stop.
transducer
9.3. Proportional pressure mode
1 [bar]
The proportional pressure operating mode reduce
data sheet
transducer
the pressure proportionally with the water demand
of the system.
data sheet
transducer
In this operating mode the frequency converter
keeps a set-point pressure at the maximum
DiFF
frequency, this set-point pressure could be set with
see motor plate
the parameter UP06.
see motor plate
The slope of the pressure-flow rate line could be set
PC
through the percentage of the pressure when flow
on demand [bar]
is equal to 0.
It is possible to have different configurations of this
operating mode related with the different types and
number of transducers installed:
Proportional pressure with 1 pressure transducer
(absolute or differential transducer).
Proportional pressure with 2 pressure transducers
in differential mode.
For detailed program settings see the following
configuration sections.
9.3.1. Proportional pressure mode with single
This configuration uses a feedback given by a
pressure transducer (connected as shown in
section 6.7).
Parameters to programm or check (recommended
sequence):
Hz=2+ √(Hset÷Hmax )x 50 (*)
Hz=2+ √(Hset÷Hmax )x 60 (*)
- H max is the maximum pump pressure, in
bar, when flow is equal to 0.
transducer (differential or absolute)
Par.
Description
AP01
Maximum pump pressure
AP02
Primary transducer supply
Primary transducer
AP03
measuring unit
Primary transducer
AP04
minimum value
Primary transducer
AP05
maximum value
UP02 Nominal pump current
UP03
Nominal pump frequency
UP05 Operating mode
UP06
Primary set-point
PP01 Percentage of the pressure
with zero flow
I-MAT_Ed5 - Operating Instructions
Suggested value
based on pump type
data sheet
transducer
1 [bar]
data sheet
transducer
data sheet
transducer
see motor plate
see motor plate
PP
on demand [bar]
50 [%]