SRX240 Services Gateway Site Electrical Wiring Guidelines

Table 36 describes the factors you must consider while planning the electrical wiring for the services gateway at your site.

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

Caution: For services gateway with AC power supplies, an external surge protective device (SPD) must be used at the AC power source.

Table 36: Site Electrical Wiring Guidelines for the Services Gateway

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:

  • Destroy the signal drivers and receivers in the device
  • Conduct power surges over the lines into the equipment, resulting in an electrical hazard

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

Caution: To comply with intrabuilding lightning/surge requirements, the intrabuilding wiring must be shielded. The shielding for the wiring must be grounded at both ends.

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