ABB ACQ810-04, Руководство по оборудованию, Страница: 35 / 144

Planning the cabinet installation 35
Planning the cabinet placement on a cable channel
Note the following when planning to place the cabinet on a cable channel:
•
The cabinet structure must be sturdy enough. If the whole cabinet base will not be
supported from below, the cabinet weight will lie on the sections that the floor carries.
•
Equip the cabinet with a sealed bottom plate and cable lead-throughs to ensure the
degree of protection and to prevent the cooling air flow from the cable channel into the
cabinet.
Planning the electromagnetic compatibility (EMC) of the
cabinet
Note following when planning the electromagnetic compatibility of the cabinet:
•
Generally, the fewer and smaller the holes in the cabinet, the better the interference
attenuation. The maximum recommended diameter of a hole in galvanic metal contact
in the covering cabinet structure is 100 mm (3.94 in). Pay special attention to the
cooling air inlet and outlet gratings.
•
The best galvanic connection between the steel panels is achieved by welding them
together as no holes are necessary. If welding is not possible, the seams between the
panels
are recommended to be left unpainted and equipped with special conductive
EMC strips to provide adequate galvanic connection. Usually, reliable strips are made
of flexible silicon mass covered with a metal mesh. The non-tightened touch-contact of
the metal surfaces is not sufficient, so a conductive gasket between the surfaces is
required. The maximum recommended distance between assembly screws is 100 mm
(3.94 in).
•
Construct sufficient high-frequency grounding network in the cabinet to avoid voltage
differences and forming of high-impedance radiator structures. A good high-frequency
The carrying structure on a cable channel
Cabinet side view with a bottom plate