Air Humidity; Motor Cooling; Operating And Control Modes; Overview - Grundfos CRE Series Installation And Operating Instructions Manual

8.4 Air humidity

Maximum air humidity: 95 %.
If the air humidity is constantly high and above 85 %, the drain
holes in the drive-end flange should be open.
See section
6.5 Drain holes.

8.5 Motor cooling

To ensure cooling of motor and electronics, the following must be
observed:
• Position the motor in such a way that adequate cooling is
ensured. See section
6.3 Ensuring motor
• The temperature of the cooling air must not exceed 122 °F.
• Keep cooling fins and fan blades clean.

9. Operating and control modes

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

9.1 Overview

Operating modes
Normal
Stop
Min.
Max.
Manual
Control modes
Constant pressure
Constant differential pressure
Constant temperature
Constant differential temperature
Constant flow rate
Constant level
Constant curve
Constant other value
Example
If the pump is fitted with a pressure sensor, the control mode
must be set to constant pressure. If the pump is for instance fitted
with a temperature sensor, the control mode should be constant
temperature. See section
9.3 Control mode
information.

9.2 Operating mode

When the operating mode is set to "Normal", the control mode
can be set to constant curve or any other control mode.
See section
Other operating modes:
• Stop
The pump has been stopped.
• Min.
The pump is operating at its minimum speed.
• Max.
cooling.
The pump is operating at its maximum speed.
• Manual
The pump is operating at a manually set speed.
Figure
Fig. 16 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 setting of
operating mode will be stored.
for further
9.3 Control mode.
16 illustrates the min. and max. curves.
H
Max.
Min.
Q
13