4.4 Mains Input
4.4.1 General Requirements
Ensure that the supply has the following properties:
•
Grounded 3-phase mains network, 400–480 V AC
•
3-phase frequency: 47–63 Hz
•
3-phase lines and PE line
•
Mains supply: 400–480 V
±
10%
•
Continuous input current SAB: 12.5 A
•
Intermittent input current SAB: 20 A
NOTICE
Use fuses and/or circuit breakers on the supply side of
the SAB to comply with CE or UL as detailed in
.
CE Compliance (IEC 60364)
UL Compliance
(NEC 2014)
Recommended
fuse size
Recommended
circuit breaker
Maximum
trip level
in [A]
Recommended
maximum fuse
size
gG-16
Eaton/Moller
PKZM0-16
16
•
Littelfuse
®
KLSR015
•
Littelfuse
®
FLSR015
Table 4.10 Fuses and Circuit Breakers
Maximum imbalance
temporary between
mains phase
3% of the rated supply voltage
True power factor [
λ
]
≥
0.9 at rated current
Switching on input
supply
Maximum 2 times per minute
Environment
according to
EN60664-1
•
Overvoltage category III
•
Pollution degree 2
Mains drop out
During low mains or a mains drop-out,
the SAB and the servo drives keep
running until the DC-link voltage drops
below 373 V. Full torque of the servo
drives cannot be expected at mains
voltage 10% below the rated supply
voltage.
Table 4.11 Additional Specifications
4.4.2 Harmonics
The VLT
®
Integrated Servo Drive ISD 510 System takes up
non-sinusoidal current from the mains, which increases the
input current IRMS. A non-sinusoidal current is transformed
by means of a Fourier analysis and split up into sine-wave
currents with different frequencies, that is different
harmonic currents
IN
with 50 Hz as the basic frequency.
The harmonics do not affect the power consumption
directly, but increase the heat losses in the installation
(transformer, cables). Consequently, in plants with a high
percentage of rectifier load, maintain harmonic currents at
a low level to avoid overload of the transformer and high
temperature in the cables.
NOTICE
Some of the harmonic currents might disturb communi-
cation equipment connected to the same transformer or
cause resonance in connection with power factor
correction units.
To ensure low harmonic currents, the SAB is equipped with
intermediate circuit coils as standard. DC-coils reduce the
total harmonic distortion (THD) to 40%.
4.4.2.1 Mains Configuration and EMC
effects
Only TN mains systems are allowed for powering the VLT
®
Integrated Servo Drive ISD 510 System.
•
TN-S: A 5-wire system with separate neutral (N)
and protective earth (PE) conductors. It provides
the best EMC properties and avoids transmitting
interference.
•
TN-C: A 4-wire system with a common neutral
and protective earth (PE) conductor throughout
the system. The combined neutral and protective
earth conductor results in poor EMC character-
istics.
IT mains systems and AC mains systems with a grounded
mains are not allowed.
4.4.2.2 Mains Transients
Transients are brief voltage peaks in the range of a few
thousand volts. They can occur in all types of power distri-
bution systems, including industrial and residential
environments.
Lightning strikes are a common cause of transients.
However, they are also caused by switching large loads on
line or off, or switching other mains transients equipment,
such as power factor correction equipment. Transients can
also be caused by short circuits, tripping of circuit breakers
in power distribution systems, and inductive coupling
between parallel cables.
EN 61000-4-1 describes the forms of these transients and
how much energy they contain. Their harmful effects can
be limited by various methods. Gas-filled surge arresters
and spark gaps provide first-level protection against high-
energy transients. For second-level protection, most
System Integration
Design Guide
MG36C102
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