Peripheral cabinets that are electrically connected to the system cabinet must have their frames electrically connected (or at the same signal reference potential) unless every connection method between the system cabinet and the peripheral cabinet is by fiber optics. For example, if a single-ended data cable connects a SCSI adapter in the system cabinet with a disk rack in a peripheral cabinet, the two cabinets must be at the same signal reference potential; that is, tied together with a signal reference strap. Relying on a clean safety ground in the power cord is not sufficient, and data corruption is likely.

If a signal reference grid already exists at the installation site, connect all cabinet ground wires to it. The cabinet has a ground wire assembly at the bottom of the frame in the rear of the cabinet. Bolt the free end of the ground wire assembly to the signal reference grid.

Connect any peripheral cabinets to the same signal reference grid. The peripheral cabinets might not have a signal reference connection point. Find a paint-free area near the bottom of the cabinet, and connect the cabinet to the signal reference grid using a signal reference strap. Once the connection is made, use an ohmmeter to verify that the electrical connection is less than 1 ohm. If a signal reference grid is not available, connect the system and peripheral cabinets together using the supplied ground wires.