68 Planning the electrical installation
•
disconnector that has an auxiliary contact that in all cases causes switching
devices to break the load circuit before the opening of the main contacts of
the disconnector (EN 60947-3)
•
circuit breaker suitable for isolation in accordance with EN 60947-2.
■
Other regions
The disconnecting device must conform to the applicable local safety regulations.
Checking the compatibility of the motor and drive
Use an asynchronous AC induction motor with the drive. Several induction motors
can be connected to the drive at a time. Check that the motor and the drive are
compatible according to the rating table in section
lists the typical motor power for each drive type.
Selecting the power cables
■
General rules
Select the input power and motor cables according to local regulations:
•
The input power and the motor cables must be able to carry the corresponding
load currents. See section
•
The cable must be rated for at least 70 °C maximum permissible temperature
of conductor in continuous use. For US, see
•
The conductivity of the PE conductor must be sufficient, see the table below.
•
600 V AC cable is accepted for up to 500 V AC.
To comply with the EMC requirements of the CE mark, use one of the approved
cable types in section
Symmetrical shielded cable reduces electromagnetic emission of the whole drive
system as well as the stress on motor insulation, bearing currents and wear.
The protective conductor must always have an adequate conductivity. The table
below shows the minimum cross-sectional area related to the phase conductor
size according to IEC 61439-1 when the phase conductor and the protective
conductor are made of the same metal.
Cross-sectional area of the phase conduct-
S (mm 2 )
16 < S ≤ 35
Ratings (page 139)
Recommended power cable types (page
ors
S ≤ 16
Ratings (page
for the rated currents.
Conduit (page
Minimum cross-sectional area of the corres-
ponding protective conductor
S p (mm 2 )
139). The table
71).
70).
S
16