ABB ACS880-34, Hardware Manual

Page: 49 / 256

Guidelines for planning the cabinet installation 49
Planning the cabinet placement on a cable channel
Note the following when you plan to place the cabinet on a cable channel:
•
The cabinet structure must be sturdy enough. If the whole cabinet base is not
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 entries to ensure the degree of
protection and to prevent the cooling air flow from the cable channel into the cabinet.
Note : When the bottom grille and clear plastic shrouds around the motor cables are
installed, the degree of protection of the drive module from bottom side is IP20.
Planning the electromagnetic compatibility (EMC) of the
cabinet
Note the following when you plan 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, we recommend to leave
the seams between the panels
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
grounding is made with short flat copper braids for low inductance. One-point high-
frequency grounding cannot be used due to the long distances inside the cabinet.
•
360° high frequency grounding of the cable shields at the cable entries improves the
EMC shielding of the cabinet.
The carrying structure on a cable channel Cabinet side view with a bottom plate