Electrical Installation - Grundfos CU 321 Notice D'installation Et D'entretien

2.3 Electrical installation

It is the responsibility of the installer to ensure
correct grounding and protection in accordance with
national and local standards.
WARNING!
The voltage of the CU 321 is dangerous
whenever the drive is connected to the AC
line. Incorrect installation of the motor or
drive may cause damage to the equip-
ment, serious injury or death.
Comply with the safety instructions in this
manual as well as local and national rules
and safety regulations.
Touching electrical parts may be fatal –
even after the equipment has been discon-
nected from the AC line.
Wait at least 4 minutes for current to
dissipate.
IMPORTANT
To eliminate the possibility of electrical interfer-
ence, do not route power cables near any other
electrical cables. Maintain a physical separation
of at least 10-12 inches.
If this is impossible or extra precautions are desired,
use a shielded cable and tie the drain wire to the
CU 321 ground lug.
2.3.1 Grounding
Comply with the following at installation:
• Safety grounding: The drive has a high leakage
current and must be grounded properly for safety.
Follow all local safety regulations.
• High frequency grounding: Keep grounding
cables as short as possible.
Since the leakage currents to ground may be higher
than 3.5 mA, the CU 321 must always be connected
to ground in accordance with applicable national and
local regulations.
Do not use GFCI together with the CU 321 due to
high leakage currents which can trip these devices.
2.3.2 Mains supply
See section 6. Technical data for correct sizing of
cable cross-section.
Connect the mains supply to terminals according to
the following table. The reinforced protective earth
must be connected to terminal
Mains supply voltages:
1 x 208-240 V ±10%
3 x 208-240 V ±10%.
Mains supply
L1
L2
L3
Ground
2.3.3 Motor connection
See the table below and section 6. Technical data in
this manual for correct sizing of cable cross-section.
Connect the motor leads to terminals according to
the table below. The reinforced protective earth must
be connected to terminal
Motor
Yellow (U)
Red (V)
Black (W)
Green (ground
.
CU 321 terminals
3 hp
1-ph 3-ph
L1
L2
–
.
CU 321 terminals
U
V
W
) Ground
L1 L3 L2
91 92 93
Fig. 15 Mains and motor terminal connections of
CU 321, 3 hp, 1-/3-ph, and 5 hp, 3-ph
91 93 92
NOT USED!
L1 (L3) L2
Fig. 16 Mains and motor terminal connections of
CU 321, 5 hp, 1-ph
5 hp
1-ph 3-ph
L1 L1 L1
L2 L2 L2
L3 – L3
Ground
U V W
96 97 98
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