Toshiba CTX28 manual Ground the System

Strata CTX670 Installation

Ground the System

Step 4: Ground the System

The system requires a solid earth ground for proper operation and safety. The AC power cord(s) already contains a conductor for the “third wire ground” provided by the commercial power outlet (see Figure 4-11, for grounding points “A” and “B”). An insulated conductor must connect the frame ground terminal on the Base Cabinet to a cold water pipe or the building ground (point “B”).

Before connecting the system to the AC power source, measure the impedance of the building ground reference. If the ground path connected to the system has an impedance of 1 ohm or more, a better ground must be installed. In Figure 4-11, the grounding path between point “A” and the single point ground “B” must be less than 0.25 ohms.

The “third wire ground” coming from the primary AC power outlet must be dedicated and must be routed through the same conduit as the phase conductors serving the system. The conductor connected to the frame ground (FG screw) on the system power supply must be insulated and comply with the general rules for grounding contained in Article 250 of the National Electrical Code, NFPA 70, but must not depend on the cord and plug of the system.

If the CTX670 system consists of more than one cabinet, you must install the bonding connection plates that come attached to each expansion cabinet. Refer to Figure 4-9. Connect the mother board ground wires and the intercabinet ground wires per Figure 4-11.

Wrap the cable mesh shield (part No. B50MT) around the 25-pair communication cables that carry stations over tip and ring, per Figure 4-10.

WARNING! Failure to provide a proper ground may be a safety hazard to service personnel or lead to confusing trouble symptoms. In extreme cases, system failure may result because the system is not properly protected from lighting or power transients.

4-18 Strata CTX I&M 06/04