Motor Cable Shield; Additional Us Requirements; Conduit; Armored Cable / Shielded Power Cable - ABB ACS800-U1 Hardware Manual

52 Planning the electrical installation

Motor cable shield


If the motor cable shield is used as the sole protective earth conductor of the motor,
ensure that the conductivity of the shield is sufficient. See IEC 61439-1. To effectively
suppress radiated and conducted radio-frequency emissions, the shield conductivity
must be at least 1/10 of the phase conductor conductivity. The requirements are
easily met with a copper or aluminum shield. The minimum requirement of the
motor cable shield of the drive is shown below. It consists of a concentric layer of
copper wires with an open helix of copper tape or copper wire. The better and
tighter the shield, the lower the emission level and bearing currents.
Insulation jacket

Additional US requirements


Type MC continuous corrugated aluminum armor cable with symmetrical grounds or
shielded power cable must be used 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 A, the power cables must be rated for 75

Conduit

Separate parts of a conduit must be coupled together, bridge the joints with a
ground conductor bonded to the conduit on each side of the joint. Bond the
conduits also to the drive enclosure and motor frame. Use separate conduits for
input power, motor, brake resistor, and control wiring. When 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.

Armored cable / shielded power cable

Six conductor (3 phases and 3 ground) type MC continuous corrugated aluminum
armor cable with symmetrical grounds is available from the following suppliers
(trade names in parentheses):
•
Anixter Wire & Cable (Philsheath)
•
BICC General Corp (Philsheath)
•
Rockbestos Co. (Gardex)
•
Oaknite (CLX)
Shielded power cables are available from Belden, LAPPKABEL (ÖLFLEX) and Pirelli.
Copper wire screen
Helix of copper
tape or copper wire
°
C (167
Inner insulation
Cable core
°
F).