Grundfos CIU 501 User Manual

10.2 Setpoint in closed-loop control
The setpoint is written to register 00104 Setpoint as a percentage
value scaled in 0.01 % of the setpoint range. The selected setpoint
is reflected in register 00338 UserSetpoint with the same scaling.
The actual setpoint, whether it has been set via Grundfos GO, the
pump display, the pump buttons or the fieldbus, can be read from
register 00308 ActualSetpoint. It is a percentage value scaled in
0.01 % of register 00211 FeedbackSensorMax.
Generally, the actual setpoint value represents head, pressure, flow,
temperature and so on depending on how the feedback sensor has
been set to measure. The unit of measure can be read from register
00209 FeedbackSensorUnit.
It is easy to calculate back and forth between the setpoint in percent
and its scaled value:
X
act
[unit] = X
set
[%] × (r
max
- r
min
) + r
min
Where:
• r
max
= SetpointRangeMax × FeedbackSensorMax ×
FeedbackSensorUnit
• r
min
= SetpointRangeMin × FeedbackSensorMax ×
FeedbackSensorUnit
1
2
3
100%
0%
6
4
100%
5
7
8
TM079761
Setpoint in closed-loop control
Pos. Description
1
Setpoint
7)
(Register 00104)
2
UserSetpoint
7)
(Register 00343)
3
ActualSetpoint
8)
(00308)
4 FeedbackSensorMax (Register 00222)
5
r
max
6
X
set
7
X
act
8
r
min
7)
Percentage of setpoint range.
8)
Percentage of sensor maximum.
MAGNA3 40-100 example
SetpointRangeMin: 5 %.
SetpointRangeMax: 50 %.
FeedbackSensorMax: 20.
FeedbackSensorUnit: m.
r
max
= SetpointRangeMax × FeedbackSensorMax ×
FeedbackSensorUnit = 50 % × 20 × m = 10 m
r
min
= SetpointRangeMin × FeedbackSensorMax ×
FeedbackSensorUnit = 5 % × 20 × m = 1 m
X
act
[unit] =
X
set
[%] × (r
max
- r
min
) + r
min
X
set
[%] × (10 m - 1 m) + 1 m
X
set
[%] × 9 m + 1 m
If X
set
[%] has value 40 %, the pump will have an actual setpoint of
40 % × 9 m + 1 m = 4.6 m.
10.3
Setpoint in open-loop control
The setpoint is written to register 00104 Setpoint as a percentage
value scaled in 0.01 % of the nominal frequency f
nom
represented
by register 00212 NomFrequency. The selected setpoint is reflected
in register 00338 UserSetpoint with the same scaling. From
fieldbus, it will get whatever value written to Setpoint. From pump
display and Grundfos GO, it is limited to range [f
min
; f
max
],
represented by 00214 MaxFrequency and 00213 MinFrequency.
The actual setpoint, whether it has been set via Grundfos GO, the
pump display, the pump buttons or the fieldbus, can be read from
register 00308 ActualSetpoint, and it always reflects the frequency
limitations. It equals the value that the pump actually uses.
1 2 3
100 %
5
6
8
0 %
7
4
TM070155
Setpoint in open-loop control
Pos. Description
1
Setpoint
9)
(Register 00104)
2
NomFrequency, Hz
(Register 00212)
3 100 %
4
MaxFrequency
(Register 00214)
5
X
set
6
MinFrequency
(Register 00213)
7 0 %
8
UserSetpoint
9)
(Register 00338)
9
ActualSetpoint
9)
(Register 00308)
10
X
act
9)
Percentage of f
nom
.
For MGE motors and the CUE drive
• [f
min
; f
max
] can be adjusted from the pump display and Grundfos
GO.
• With f
max
> f
nom
a setpoint above 100 % is possible, over
synchronous.
For MAGNA3
• [f
min
; f
max
] are fixed.
• f
max
always equals f
nom
.
30
English (GB)

Grundfos CIU 501 Specifications

General

Brand	Grundfos
Model	CIU 501
Category	Controller
Language	English