earth conductor must be determined in a manner which produces a conductance
equivalent to that which results from the application of this table.
Minimum cross-sectional area of the corres-
ponding protective earth conductor
S
p
(mm
2
)
Cross-sectional area of the phase conduct-
ors
S (mm
2
)
S
1)
S ≤ 16
1616 < S ≤ 35
S/235 < S
1)
For the minimum conductor size in IEC installations, refer to Additional grounding requirements – IEC.
If the protective earth conductor is not part of the input power cable or input
power cable enclosure, the minimum permitted cross-sectional area is:
• 2.5 mm
2
if the conductor is mechanically protected,
or
• 4 mm
2
if the conductor is not mechanically protected. If the equipment is
cord-connected, the protective earth conductor must be the last conductor
to be interrupted if there is a failure in the strain relief mechanism.
￭
Additional grounding requirements – IEC
This section gives grounding requirements according to standard IEC/EN 61800-5-1.
Because the normal touch current of the drive is more than 3.5 mA AC or 10 mA DC:
• the minimum size of the protective earth conductor must comply with the
local safety regulations for high protective earth conductor current equipment,
and
• you must use one of these connection methods:
1. a fixed connection and:
• a protective earth conductor with a minimum cross-sectional area of
10 mm
2
Cu or 16 mm
2
Al (as an alternative when aluminum cables are
permitted),
or
• a second protective earth conductor of the same cross-sectional area
as the original protective earth conductor,
or
• a device that automatically disconnects the supply if the protective
earth conductor is damaged.
2. a connection with an industrial connector according to IEC 60309 and a
minimum protective earth conductor cross-section of 2.5 mm
2
as part of
a multi-conductor power cable. Sufficient strain relief must be provided.
Guidelines for planning the electrical installation 51
To Next Page
Loading...
Need help?
General
