4-2
Practices
should be made of zinc-plated mild steel. If painted, remove the paint at
each mounting and grounding point.
Zinc-plated steel is strongly recommended due to its inherent ability to bond
with the drive chassis and resist corrosion. The disadvantage with painted
panels, apart from the cost in labor to remove the paint, is the difficulty in
making quality control checks to verify if the paint has been properly
removed, and any future corrosion of the unprotected mild steel may
compromise noise performance.
Plain stainless steel panels are also acceptable but are inferior to zinc-plated
mild steel due to their higher ohms-per-square resistance.
Though not always applicable, a plated cabinet frame is also highly
desirable since it makes a high frequency bond between panel and cabinet
sections more reliable.
Doors
For doors 2 m (78 in.) in height, ground the door to the cabinet with two or
three braided straps.
EMC seals are not normally required for industrial systems.
EMC Specific Installations
A steel enclosure is recommended. A steel enclosure can help guard against
radiated noise to meet EMC standards. If the enclosure door has a viewing
window, it should be a laminated screen or a conductive optical substrate to
block EMC.
Do not rely on the hinge for electrical contact between the door and the
enclosure - install a grounding wire. For doors 2 m (78 in.) in height, two or
three braided grounding straps between the door and the cabinet should be
used. EMC gaskets are not normally required for industrial systems.
Layout
Plan the cabinet layout so that drives are separated from sensitive
equipment. Choose conduit entry points that allow any common mode noise
to remain away from PLCs and other equipment that may be susceptible to
noise. Refer to
for additional information.
Summary of Contents for Allen-Bradley 1305-AA02A
Page 4: ...ii Summary of Changes Notes ...
Page 40: ...2 18 Power Distribution Notes ...
Page 48: ...3 8 Grounding Notes ...
Page 68: ...4 20 Practices Notes ...
Page 78: ...6 8 Electromagnetic Interference Notes ...
Page 94: ...Glossary 4 UL Underwriters Laboratories ...
Page 100: ...Index 6 ...
Page 101: ......