Mains And Motor Connection - Grundfos CUE 150 hp Notice D'installation Et D'entretien

The leakage current from the CUE in normal operation can be
seen in section 16.7.1 Mains supply (L1, L2, L3).
During start and in asymmetrical supply systems, the leakage
current can be higher than normal and may cause the ELCB to
trip.
6.1.4 Motor protection
The motor requires no external motor protection. The CUE
protects the motor against thermal overloading and blocking.
6.1.5 Protection against overcurrent
The CUE has an internal overcurrent protection for overload
protection on the motor output.
6.1.6 Protection against supply voltage transients
The CUE is protected against supply voltage transients according
to EN 61800-3, second environment.

6.2 Mains and motor connection

The supply voltage and frequency are marked on the CUE
nameplate. Make sure that the CUE is suitable for the power
supply of the installation site.
The maximum output voltage of the CUE is equal
to the input voltage.
Note
Example: If the supply voltage is 208 V, choose
a 208 V rated motor.
6.2.1 Mains switch
A mains switch can be installed before the CUE according to local
regulations. See fig. 10.
6.2.2 Wiring diagram
The wires in the terminal box must be as short as possible.
Excepted from this is the ground conductor which must be so long
that it is the last one to be disconnected in case the cable is
inadvertently pulled out of the cable entry.
Fig. 11 Wiring diagram, three-phase mains connection
Terminal Function
91 (L1)
92 (L2) Three-phase supply
93 (L3)
95/99 (PE) Ground connection
96 (U)
Three-phase motor connection, 0-100 % of
97 (V)
supply voltage
98 (W)
10
6.2.3 Gland plate
Cables are connected through the gland plate from the bottom.
The gland plate must be fitted to the CUE to ensure the specified
protection degree as well as to ensure sufficient cooling.
Drill holes in the marked areas. See fig. 12.
Fig. 12 CUE viewed from the bottom
6.2.4 Motor connection
For information about enclosure, see table in section 16.1.
The motor cable must be screened for the CUE to
Caution
meet EMC requirements.
1. Connect the ground conductor to terminal 99 (PE). See fig. 14.
2. Connect the motor conductors to the terminals 96 (U), 97 (V),
98 (W). See fig. 15.
3. Fix the screened cable with a cable clamp.
4. Fit the EMC metal cover to ensure best EMC performance
before connecting the mains cable. See fig. 13.
Fig. 13 Fitting the EMC metal cover
The cable screen must be exposed and in
physical contact with the mounting plate and
Note
clamp.
6.2.5 Mains connection
Check that mains voltage and frequency
correspond to the values on the nameplate of the
Caution
CUE and the motor.
1. Connect the ground conductor to terminal 95 (PE). See fig. 14.
2. Connect the mains conductors to the terminals 91 (L1),
92 (L2), 93 (L3). See fig. 15.
3. Fix the mains cable with a cable clamp.
Mains
Motor