ABB ACS850 series, Hardware Manual

Page: 43 / 120

Planning the electrical installation
43
Selecting the power cables
General rules
Dimension the supply (input power) and motor cables according to local
regulations .
• The cable must be able to carry the drive load current. See the chapter Technical
data for the rated currents.
• The cable must be rated for at least 70
°
C (US: 75 °C [167 °F]) maximum
permissible temperature of conductor in continuous use.
• The inductance and impedance of the PE conductor/cable (grounding wire) must
be rated according to permissible touch voltage appearing under fault conditions
(so that the fault point voltage will not rise excessively when a ground fault
occurs).
• 600 VAC cable is accepted for up to 500 VAC.
• Refer to the chapter Technical data for EMC requirements.
Symmetrical shielded motor cable must be used (see the figure below) to meet the
EMC requirements of the CE and C-tick marks.
A four-conductor system is allowed for input cabling, but shielded symmetrical cable
is recommended. To operate as a protective conductor, the shield conductivity must
be as follows when the protective conductor is made of the same metal as the phase
conductors:
Compared to a four-conductor system, the use of symmetrical shielded cable
reduces electromagnetic emission of the whole drive system as well as motor
bearing currents and wear.
The motor cable and its PE pigtail (twisted shield) should be kept as short as
possible in order to reduce electromagnetic emission, as well as stray currents
outside the cable and capacitive current.
Cross-sectional area of one phase conductor
(S)
Minimum cross-sectional area of protective
conductor (S
p
)
S < 16 mm
2
S
16 mm
2
< S < 35 mm
2
16 mm
2
35 mm
2
< S S/2