Electrostatic discharge (ESD) protection
21
Model 6476 User Guide
2 • Chassis specifications
Figure 6. EMC strip and gasket on chassis and cards
The EMC strip on the left side of the board mates with the EMC gasket attached to the chassis when it is
plugged into the first slot. Each board mates together with corresponding gaskets/strips.
In addition, all aluminum components of the subrack are surface treated and conductive. Top, bottom, sides
and rear EMC covers provide mechanical protection and EMC shielding on the subrack. Retaining clips
ensure conductive connection.
The chassis contains an optional frame ground to signal ground jumper. By default, in all ForeFront FullPipe
products, this jumper is not installed. This means that frame ground (the electrical potential of the chassis shell
itself and all panels, screws, etc. that are connected to it) is electrically isolated from the signal ground (the elec-
trical potential corresponding to “0 volts” with respect to the power supplies and cards in the chassis). Patton
Electronics recommends that this isolation be maintained, in order to improve the EMC characteristics of the
system and the integrity of the two distinct grounds.
See the chapter on installation and maintenance for further information on the jumper settings.
Electrostatic discharge (ESD) protection
The 6476 ForeFront FullPipe chassis provides ESD protection in compliance with IEEE 1101.10. ESD con-
tacts are embedded inside and in the front section of card guides for making early as possible contact with a
discharge strip on one or both, the upper and/or lower edge of the plug-in board/module. Only the card guides
located at the bottom rail of the chassis (right vertical rail for the 4U chassis), both front and rear (when there
is a transition module present in the chassis), contain the ESD clips. The ESD clip in the card guide is con-
nected to the Chassis GND (ground).
There is an alignment/ESD pin on the injector/ejector handle of boards (see
figure 7
).
