Bus Connection Cable; Operating Conditions; Maximum Number Of Starts And Stops; Ambient Temperature - Grundfos CRE Series Installation And Operating Instructions Manual

7.7 Bus connection cable

7.7.1 New installations
For the bus connection, use a screened 3-core cable with a
conductor cross-section 28-16 AWG.
• If the motor is connected to a unit with a cable clamp which is
identical to the one on the motor, connect the screen to this
cable clamp.
• If the unit has no cable clamp as shown in fig. 13, leave the
screen unconnected at this end.
A
1
2
Y
3
B
Fig. 13 Connection with screened 3-core cable
7.7.2 Replacing an existing motor
• If a screened 2-core cable is used in the existing installation,
connect it as shown in fig. 14.
A
1
Y
2
B
Fig. 14 Connection with screened 2-core cable
• If a screened 3-core cable is used in the existing installation,
follow the instructions in section
12
Motor
A
1
2
Y
3
B
Motor
A
1
Y
2
B
7.7.1 New installations.

8. Operating conditions

8.1 Maximum number of starts and stops

The number of starts and stops via the power supply must not
exceed four times per hour.
When switched on via the power supply, the pump will start after
approx. 5 seconds.
If a higher number of starts and stops is desired, use the input for
external start/stop when starting/stopping the pump.
When started via an external on/off switch, the pump will start
immediately.

8.2 Ambient temperature

8.2.1 Ambient temperature during storage and transportation
Minimum -22 °F
Maximum +140 °F.
8.2.2 Ambient temperature during operation
Minimum -4 °F
Maximum -122 °F.
The motor can operate with the rated power output (P2) at 122 °F,
but continuous operation at higher temperatures will reduce the
expected product life. If the motor is to operate at ambient
temperatures between 122 and 140 °F, an oversized motor must
be selected. Contact Grundfos for further information.

8.3 Installation altitude

The motor must not be installed more than
Caution
6560 ft above sea level.
Installation altitude is the height above sea level of the installation
site.
• Motors installed up to 3280 ft above sea level can be loaded
100 %.
• Motors installed more than 3280 ft above sea level must not
be fully loaded due to the low density and consequent low
cooling effect of the air. See fig. 15.
P2
[%]
1
0.99
0.98
0.97
0.96
0.95
0.94
0.93
0.92
0.91
0.90
0.89
0.88
0
0 3281 3937 4593 5249 5906 6562 7218
Fig. 15 Derating of motor output power (P2) in relation to
altitude above sea level
[ft]