Product Manual

CU331SP variable frequency drive
SQ, SQE, CU 331, and SP
10
42
Space requirements and air circulation
CU331SP units can be mounted side by side, but as a
sufficient air circulation is required for cooling these
requirements must be met:
• Sufficient free space above and below the
CU331SP
• Ambient temperature up to 122°F (50 °C)
• Hang the CU331SP directly on the wall, or fit it with
a back plate. See fig. 29.
Fig. 29 CU331SP hung directly on the wall or fitted with a
back plate
Required free space above and below the CU331SP:
For information about enclosure, see section
Enclosure on page 49.
Mounting
The CU331SP must be mounted securely on a firm
surface. Ensure that screws are sized appropriately for
the weight of the CU331SP (approximately 60 lbs) and
anchored securely to the mounting surface.
1. Mark and drill holes. See fig. 30; also see section
Main dimensions and weight on page 49.
2. Fit the screws, but leave loose. Mount the
CU331SP, and tighten the four screws.
Fig. 30 Drilling holes for mounting
CU331SP electrical connection
Ensure the correct grounding and protection
procedures are used for the installation. Before the
electrical installation, ensure that the power supply and
other voltage inputs are switched off.
Electrical protection
Protection against electric shock, indirect contact
The leakage current to ground exceeds 3.5 mA, and a
reinforced ground connection is required.
Protective conductors must always have a yellow/
green (PE) or yellow/green/blue (PEN) color marking.
Instructions according to EN IEC 61800-5-1:
• The CU331SP must be stationary, installed
permanently and connected permanently to the
mains supply.
• The ground connection must be carried out with
duplicate protective conductors or with a single
reinforced protective conductor with a cross-section
of minimum AWG 7 (10 mm
2
).
Protection against short-circuit, fuses
The CU331SP and the supply system must be
protected against short-circuit.
Grundfos requires that the back-up fuses are used for
protection against short-circuit.
The CU331SP offers complete short-circuit protection
in case of a short-circuit on the motor output.
Additional protection
The leakage current to ground exceeds 3.5 mA.
If the CU331SP is connected to an electrical
installation where an earth leakage circuit breaker
(ELCB) is used as additional protection, the circuit
breaker must be of a type marked with the following
symbols:
Fig. 31 Circuit breaker type B
The total leakage current of all the electrical equipment
in the installation must be taken into account.
During start and in asymmetrical supply systems, the
leakage current can be higher than normal and may
cause the ELCB to trip.
Motor protection
The motor requires no external motor protection. The
CU331SP protects the motor against thermal
overloading and blocking.
TM03 8859 2607
Enclosure Space [in (mm)]
B1 7.9 (200)
TM03 8860 2607
b
aa
b
ELCB