Earthing And Earth Fault Protection - Siemens BT300 Manual

Siemens Industry, Inc. • 5
1.3

Earthing and earth fault protection

CAUTION!
13006.emf
The Siemens BT300 AC drive must always be grounded with an earthing conductor connected to the
earthing terminal marked with
The touch current of Siemens BT300 exceeds 3.5 mA AC. According to EN 61800-5-1, one or more of
the following conditions for the associated protective circuit shall be satisfied:
A fixed connection and
a) the protective earthing conductor shall have a cross-sectional area of at least 10 mm
(8 AWG) Cu or 16 mm
or
b) an automatic disconnection of the supply in case of discontinuity of the protective
earthing conductor. See Chapter 4.
or
c) provision of an additional terminal for a second protective earthing conductor of the
same cross-sectional area as the original protective earthing conductor.
Cross-sectional area of phase conductors (S)
2
mm (AWG)
S 16 (6)
≤
16 (6) < S 35 (2)
≤
35 (2) < S
The values above are valid only if the protective earthing conductor is made of the same metal as
the phase conductors. 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.
The cross-sectional area of every protective earthing conductor which does not form a part of the supply
cable or cable enclosure shall, in any case, be not less than
• 2.5 mm 2 (14 AWG) if mechanical protection is provided or
2
• 4 mm (12 AWG) if mechanical protection is not provided. For cord-connected equip-
ment, provisions shall be made so that the protective earthing conductor in the cord
shall, in the case of failure of the strain-relief mechanism, be the last conductor to be
interrupted.
However, always follow the local regulations for the minimum size of the protective earthing conductor.
NOTE:
Due to the high capacitive currents present in the drive, fault current protective switches may
not function properly.
Do not perform any voltage withstand tests on any part of Siemens BT300. There is a cer-
tain procedure according to which the tests shall be performed. Ignoring this procedure
may result in damaged product.
13006.emf
24-hour support +1-800-877-7545 (Dial 2)
.
2
(6 AWG) Al.
Table 2. Protective earthing conductor cross-section
Minimum cross-sectional area of the corre-
sponding protective earthing conductor
2
mm (AWG)
S
16 (6)
S/2 (14)
Safety
2