KFU 2-/4-
36
5 Electrical
Installation
The electrical installation must be carried out by qualified staff according to the gen-
eral and regional safety and installation directives. For a safe operation of the fre-
quency inverter it is necessary that the documentation and the device specifications
be complied with during installation and commissioning. In the case of special applica-
tions, you may also have to comply with further guidelines and instructions.
Danger!
When the frequency inverter is disconnected from power supply, the
mains, DC-link voltage and motor terminals may still be live for some
time. Wait for some minutes until the DC link capacitors have discharged
before starting to work at the unit.
The connecting cables must be protected externally, considering the maximum volt-
age and current values of the fuses. The mains fuses and cable cross-sections are to
be selected according to EN 60204-1 and DIN VDE 0298 Part 4 for the nominal oper-
ating point of the frequency inverter. According to UL/CSA, the frequency inverter is
suitable for operation at a supply network of a maximum of 480 VAC which delivers a
maximum symmetrical current of 5000 A (effective value) if protected by fuses of class
RK5. Only use copper cables with a temperature range of 60/75 °C.
Warning!
The frequency inverters are to be grounded properly, i.e. large connec-
tion area and with good conductivity. The leakage current of the fre-
quency inverters may be > 3.5 mA. According to EN 50178 a permanent
connection must be provided. The protective conductor cross-section
required for grounding the fixing plate must be selected according to the
size of the unit. In these applications, the cross-section must correspond
to the recommended cross-section of the wire.
Note:
Degree of protection IP20 is only achieved with terminals plugged and
properly mounted covers.
Connection conditions
The frequency inverter is suited for connection to the public or industrial supply
mains according to the technical data. If the transformer output of the supply
mains is
≤
500 kVA, a mains commutation choke is only necessary for the fre-
quency inverters identified in the technical data. The other frequency inverters are
suitable for connection without a mains commutating choke with a relative mains
impedance
1%.
It must be checked, based on the specifications of EN 61000-3-2, if the devices
can be connected to the public supply means without taking additional measures.
The frequency inverters
≤
9.2 kW with integrated EMC filter comply with the emis-
sion limits of the product standard EN 61800-3 up to a motor cable length of 10 m,
without additional measures being required. Increased requirements in connection
with the specific application of the frequency inverter are to be met by means of
optional components. Commutating chokes and EMC filters are optionally avail-
able for the series of devices.
Operation on unearthed mains (IT mains) is admissible after disconnection of the
Y capacitors in the interior of the device.
Interference-free operation with residual current device is guaranteed at a tripping
current
30 mA if the following points are observed:
one-phase power supply (L1/N): Pulse current and alternating current sensi-
tive residual current devices (Type A to EN 50178)
two-phase power supply (L1/L2) or
three-phase power supply (L1/L2/L3):
All-current sensitive residual current devices (Type B to EN 50178)
Use EMC filters with reduced leakage current or, if possible, do not use EMC
filters at all.
The length of the shielded motor cable is
≤
10 m and there are no additional
capacitive components between the mains or motor cables and PE.
