BENSHAW RSi S4 Series, Руководство пользователя

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4 - CONNECTIONS
INTERFERENCE SUPPRESSION MEASURES
4.6 Interference Suppression Measures
Electrical/electronic devices are capable of influencing or disturbing each other through connecting cables
or other metallic connections. Interference suppression measures (electromagnetic compatibility) consists
of two elements: interference resistance and interference emission.
Correct installation of the inverter in conjunction with any possible local interference suppression
measures has a crucial effect on minimizing or suppressing mutual interference.
4.6.1 Guidelines for Interference Suppression
The following guidelines assume a power source that is not contaminated by high frequency interference.
Other measures may be necessary to reduce or suppress interference if the power source is contaminated,
and no general recommendations can be given for such cases. Please consult Benshaw’s Electrical
Application Engineering Department if the following recommended interference suppression measures do
not produce the desired result.
Guidelines are as follows:
When dealing with RFI (radio frequency interference), the surface area of the conductors is a more
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critical consideration than its cross sectional area. Since high frequency interference does not flow
through the entire cross section of the conductor, but tends to stay toward its outer surface (skin effect),
braided copper tapes of equal cross section should be used.
A central grounding point should be used for interference suppression. Route the ground cables radially
from this point, avoiding loops which may lead to interference. The inverter and all components used for
interference suppression, particularly the shield of the motor cable, should be connected over as large a
surface area as possible when passing over metallic surfaces. Remove the paint from contact surfaces to
ensure a good electrical connection. See Figure 19 for recommended connection technique.
Figure 19: Recommended Connection Technique
Take care not to damage the shield cross section when connecting it to the continuing lines. This
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raises the RF resistance of the shield and radiates rather than discharges the RF energy traveling on
the shield. Shields, particularly those on control cables, must not be routed through pin contacts (plug
connectors).
When shielded cables must pass through a plug connection, use the metallic hand guard of the plug for
the continuation of the shield. It is strongly recommended that the shield be uninterrupted whenever
possible.
Use a shielded motor cable which is grounded over a large surface area at both ends. The shield on
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this cable should be uninterrupted. If a shielded motor cable cannot be used, the unshielded motor line
should be laid in a metal conduit or duct which is uninterrupted and grounded at both ends.