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Site Electrical Wiring Guidelines


Table 1 describes the factors you must consider while planning the electrical wiring at your site.


It is particularly important to provide a properly grounded and shielded environment and to use electrical surge-suppression devices.

Table 1: Site Electrical Wiring Guidelines

Site Wiring Factor


Signaling limitations

To ensure that signaling functions optimally:

  • Install wires correctly.

    Improperly installed wires can emit radio interference.

  • Do not exceed the recommended distances or pass wires between buildings.

    The potential for damage from lightning strikes increases if wires exceed recommended distances or if wires pass between buildings.

  • Shield all conductors.

    The electromagnetic pulse (EMP) caused by lightning can damage unshielded conductors and destroy electronic devices.

Radio frequency interference (RFI)

To reduce or eliminate the emission of RFI from your site wiring:

  • Use twisted-pair cable with a good distribution of grounding conductors.

  • Use a high-quality twisted-pair cable with one ground conductor for each data signal when applicable, if you must exceed the recommended distances.

Electromagnetic compatibility (EMC)

Provide a properly grounded and shielded environment and use electrical surge-suppression devices.

Strong sources of electromagnetic interference (EMI) can cause the following damage:

  • Destruction of the signal drivers and receivers in the device.

  • Electrical hazards as a result of power surges conducted over the lines into the equipment.

Tip: If your site is susceptible to problems with EMC, particularly from lightning or radio transmitters, you might want to seek expert advice.


Some ports are designed for use as intrabuilding interfaces only Type 2 or Type 4 ports, the battery return connection is to be treated as an Isolated DC return (that is, DC-I), as defined in GR-1089-CORE and require isolation from the exposed OSP cabling. To comply with NEBS requirements and protect against lightning surges and commercial power disturbances, the intrabuilding port(s) of the device MUST NOT be metallically connected to interfaces that connect to the OSP or its wiring. The intrabuilding port(s) of the device is suitable for connection to intrabuilding or unexposed wiring or cabling only. The addition of primary protectors is not sufficient protection to connect these interfaces metallically to OSP wiring.