Selecting The Power Cables; General Rules - ABB ACS800-U4 Hardware Manual

Selecting the power cables

General rules

Dimension the mains (input power) and motor cables according to local
regulations:
• The cable must be able to carry the drive load current. See chapter
data
• The cable must be rated for at least 70
conductor in continuous use. For US, see section
• 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 V AC cable is accepted for up to 500 V AC. 750 V AC cable is accepted for
up to 600 V AC. For 690 V AC rated equipment, the rated voltage between the
conductors of the cable should be minimum 1 kV.
For drive frame size R5 and larger, or motors larger than 30 kW (40 HP),
symmetrical shielded motor cable must be used (figure below). A four-conductor
system can be used up to frame size R4 with up to 30 kW (40 HP) motors, but
shielded symmetrical motor cable is always recommended. The shield(s) of motor
cable(s) must have 360° bonding at both ends.
Note: When continuous metal conduit is employed, shielded cable is not required.
The conduit must have bonding at both ends as with cable shield.
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:
Cross-sectional area of 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 the stress on
motor insulation, bearing currents and wear.
The motor cable and its PE pigtail (twisted shield) should be kept as short as
possible in order to reduce high frequency electromagnetic emission, as well as
stray currents outside the cable and capacitive current (relevant in power range
below 20 kW).
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
for the rated currents.
2
S (mm )
S < 16
16 < S < 35
35 < S
°
C maximum permissible temperature of
Additional US
Minimum cross-sectional area of the corresponding
protective conductor
S
p
Planning the electrical installation
Technical
requirements.
2
(mm )
S
16
S/2
51