Bus Connection Cable; Modes; Overview Of Modes; Operating Mode - Grundfos CRE Series Installation And Operating Instructions Manual

6.6 Bus connection cable

6.6.1 New installations
For the bus connection, use a screened 3-core cable with a
conductor cross-section of 28AWG - 16AWG.
• If the pump is connected to a unit with a cable clamp which is
identical to the one on the pump, connect the screen to this
cable clamp.
• If the unit has no cable clamp as shown in fig. 16, leave the
screen unconnected at this end.
A
1
2
Y
3
B
Fig. 16 Connection with screened 3-core cable
6.6.2 Replacing an existing pump
• If a screened 2-core cable is used in the existing installation,
connect it as shown in fig. 17.
A
1
Y
2
B
Fig. 17 Connection with screened 2-core cable
• If a screened 3-core cable is used in the existing installation,
follow the instructions in section 6.6.1 New installations on
page 12.

7. Modes

Grundfos E-pumps are set and controlled according to operating
and control modes.

7.1 Overview of modes

Normal
Operating modes
Uncontrolled
Control modes
Constant
curve
1) For this control mode the pump is equipped with a pressure
sensor. The pump may also be equipped with a temperature
sensor in which case the description would be constant
temperature in control mode controlled.

7.2 Operating mode

When the operating mode is set to Normal, the control mode can
be set to controlled or uncontrolled. See section 7.3 Control mode
on page 12.
12
Pump
A
1
2
Y
3
B
Pump
A
1
Y
2
B
Stop Min. Max.
Controlled
Constant
1)
pressure
DBP-1 - GRUNDFOS PUMP CRE - 99392005
The other operating modes that can be selected are Stop, Min. or
Max.
• the pump has been stopped
Stop:
• the pump is operating at its minimum speed
Min.:
• Max.: the pump is operating at its maximum speed.
Figure 18 is a schematic illustration of min. and max. curves.
H
Min.
Fig. 18 Min. and max. curves
The max. curve can for instance be used in connection with the
venting procedure during installation.
The min. curve can be used in periods in which a minimum flow is
required.
If the power supply to the pump is disconnected, the mode setting
will be stored.
The remote control R100 offers additional possibilities of setting
and status displays. See section 10. Setting by means of R100 on
page 14.

7.3 Control mode

7.3.1 Pumps without factory-fitted sensor
The pumps are factory-set to control mode uncontrolled.
In control mode uncontrolled, the pump will operate according to
the constant curve set, fig. 19.
H
Fig. 19 Pump in control mode uncontrolled (constant curve)
7.3.2 Pumps with pressure sensor
The pump can be set to one of two control modes, i.e. controlled
and uncontrolled, fig. 20.
In control mode controlled, the pump will adjust its performance,
i.e. pump discharge pressure, to the desired setpoint for the
control parameter.
In control mode uncontrolled, the pump will operate according to
the constant curve set.
Max.
Q
Q