Planning the electrical installation
62
3ADW000462R0401 DCS880 Hardware manual e d
Selecting the power cables
General rules
– Select the input power and motor cables according to local regulations.
– Select a cable capable of carrying the drive nominal current. See chapter
– Select a cable rated for at least 60
°
C 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).
– A 600 V
AC
cable is accepted for up to 500 V
AC
.
– A 750 V
AC
cable is accepted for up to 600 V
AC
.
– For 690 V
AC
rated equipment, the rated voltage between the conductors (L1, L2, L3) of the cable should be
at least 1 kV.
– For mains voltages exceeding 690 V
AC
and DC voltages exceeding 850 V
DC
select power cables which
comply with local regulations.
It is recommended to select following cables:
– UL: 2 kV voltage class.
– EN: Rated voltage conductor to earth 1000 V
AC
/1500 V
DC
and rated voltage conductor to conductor
1600 V
AC
/3000 V
DC
.
– The protective conductor must always have an adequate conductivity.
Unless local wiring regulations state otherwise, the cross-sectional area of the protective conductor must
agree with the conditions that require automatic disconnection of the supply required in 411.3.2. of IEC
60364-4-41:2005 and be capable of withstanding the prospective fault current during the disconnection time
of the protective device. The cross-sectional area of the protective conductor can either be selected from
the table below or calculated according to 543.1 of IEC 60364-5-54.
The table below shows the minimum cross-sectional area related to the phase conductor size according to
IEC 61800-5-1 when the phase conductor and the protective conductor are made of the same metal. If this
is not so, the cross-sectional area of the protective earthing conductor shall be determined in a manner
which produces a conductance equivalent to that which results from the application of this table.
Additional US requirements
Use type MC continuous corrugated aluminum armor cable with symmetrical grounds or shielded power cable
for the motor cables if metallic conduit is not used. For the North American market, 600 V
AC
cable is accepted
for up to 500 V
AC
. 1000 V
AC
cable is required above 500 V
AC
(below 600 V
AC
). For drives rated over 100
amperes, the power cables must be rated for 75°C (167°F)
Conduit
Couple separate parts of a conduit together. Bridge the joints with a ground conductor bonded to the conduit on
each side of the joint. Also bond the conduits to the drive enclosure and motor frame. Use separate conduits for
input power, motor, brake resistor and control wiring. When a conduit is employed, type MC continuous
corrugated aluminum armor cable or shielded cable is not required. A dedicated ground cable is always
required.
Note:
Do not run motor wiring from more than one drive in the same conduit.
Cross-sectional area of the phase conductors
S (mm
2
)
Minimum cross-sectional area of the corresponding
protective conductor
Sp (mm
2
)
S
≤
16
S
16 < S
≤
35
16
35 < S
S/2
