Grundfos CIU 501 User Manual

10. Detailed descriptions of registers
10.1 Control mode
The supported control modes are described further in this section. The control mode is set with register 00102 and its status can be read from
register 00203.
Control modes Description Illustration
> Constant speed (0)
> Constant frequency (1)
Open loop
The setpoint of the E-pump is interpreted as the setpoint for the
performance.
The setpoint value is a percentage of the maximum performance of
the E-pump.
No sensor is required in these modes.
H
Q
TM079755
T
> Constant head (3)
> Constant pressure (4)
> Constant differential pressure (5)
Closed loop:
The setpoint of the E-pump is interpreted as the setpoint for the
pressure.
The E-pump adapts the speed so that the pressure is constant,
regardless of the flow.
A pressure sensor is required, except for MAGNA3.
H
Q
TM079756
> Constant flow (7)
> Constant temperature (8)
> Constant level (10)
Closed loop:
The setpoint of the E-pump is interpreted as the setpoint for the
flow, temperature or level. Constant flow is indicated in the
diagram.
A relevant sensor is required:
a flow sensor for flow control
a temperature sensor for temperature control
a level sensor for level control
H
Q
TM079754
> Proportional pressure (6)
Closed loop:
The setpoint of the E-pump is interpreted as the setpoint in
proportional-pressure mode as shown in the diagram.
A pressure sensor is required, except for MAGNA3.
H
Q
TM079757
> AUTOADAPT (128)
In this control mode, the setpoint curve is a proportional-pressure
curve where the setpoint has been set from factory. The
AUTOADAPT algorithm in the pump will, over time, optimise the
setpoint value according to the pipe characteristics of the system.
The setpoint curve is adjusted in a downward direction.
A pressure sensor is required, except for MAGNA3.
Q
H
TM053241
> FLOWADAPT (129)
This control mode works similar to AUTOADAPT, except that the
flow-limiting function, FLOWLIMIT, is always active and limits the
flow to the value ActualMaxFlowLimit.
A pressure sensor is required, except for MAGNA3.
H
Q
TM053242
> Closed-loop sensor (130)
This is a general purpose closed-loop control mode that you can
use in cases where the pump is used for a type of control not
covered by one of the other control mode
H: Pressure (head)
Q: Flow
29
English (GB)

Grundfos CIU 501 Specifications

General

Type	CIU 501
Enclosure class	IP65
Power supply	24 V DC
Weight	0.5 kg
Communication	Modbus RTU
Storage temperature range	-40°C to +70°C
Relative humidity	5% to 95%
Housing material	Polycarbonate
Protection class	Class II