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SRX320 Site Guidelines and Requirements

SRX320 Firewall General Site Guidelines

The following precautions help you plan an acceptable operating environment for your SRX320 Firewall and avoid environmentally caused equipment failures:

  • For the cooling system to function properly, the airflow around the chassis must be unrestricted. Allow sufficient clearance between the front and back of the chassis and adjacent equipment. Ensure that there is adequate circulation in the installation location.

  • Follow the ESD procedures to avoid damaging equipment. Static discharge can cause components to fail completely or intermittently over time. For more information, see Prevention of Electrostatic Discharge Damage.

  • Ensure that a blank Mini-PIM panel is installed in the empty slot to prevent any interruption or reduction in the flow of air across internal components.

SRX320 Firewall Environmental Specifications

Table 1 provides the required environmental conditions for normal SRX320 Firewall operations.

Table 1: Environmental Specifications for the SRX320 Firewall




No performance degradation up to 10,000 ft (3048 m)

Relative humidity

5% to 95%, noncondensing


  • Operational temperature—32° F (0° C) to 104° F (40° C)

  • Nonoperational temperature—4° F (-20° C) to 158° F (70° C)

Average power consumption

46 W (non-PoE model)

221 W (PoE model)

Rated DC input power

12 VDC, 4.7 A maximum (non-PoE model)

54 VDC, 4.6 A maximum (PoE model)

Average heat dissipation

157 BTU/hr (non-PoE model)

755 BTU/hr (PoE model)

Noise level

37 dBA (non-PoE model)

40 dBA (PoE model)

SRX320 Firewall Electrical Wiring Guidelines

Table 2 describes the factors you must consider while planning the electrical wiring for the services gateway at your site.


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

Table 2: Site Electrical Wiring Guidelines for the SRX320 Firewall

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


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


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

SRX320 Firewall Grounding Specifications

To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, the SRX320 Firewall must be adequately grounded before power is connected. You must provide a grounding lug to connect the services gateway to earth ground.


Before you connect power to the services gateway, a licensed electrician must attach a cable lug to the grounding and power cables that you supply. A cable with an incorrectly attached lug can damage the services gateway (for example, by causing a short circuit).

The services gateway chassis has one grounding point on the back panel.

You must install the SRX320 in a restricted-access location and ensure that the chassis is always properly grounded. The SRX320 has a single-hole protective grounding terminal provided on the chassis. Under all circumstances, use this grounding connection to ground the chassis. For AC-powered systems, you must also use the grounding wire in the AC power cord along with the single-hole grounding lug connection. This tested system meets or exceeds all applicable EMC regulatory requirements with the single-hole protective grounding terminal.

Table 3 lists the specifications of the grounding cable used with the device.

Table 3: Grounding Cable Specifications for the Services Gateway

Grounding Requirement


Grounding cable

14 AWG single-strand wire cable

Amperage of grounding cable

Up to 4 A

Grounding lug

Ring-type, vinyl-insulated TV14-6R lug or equivalent

SRX320 Firewall Physical Specifications

Table 4 lists the physical specifications for the services gateway.

Table 4: Physical Specifications for the SRX320 Firewall

Physical Specification of Chassis




7.52 in.

7.52 in.


11.81 in.

11.81 in.


1.73 in.

1.73 in.


3.28 lb

3.4 lb

SRX320 Firewall Clearance Requirements for Airflow and Hardware Maintenance

When planning the installation site for the SRX320 Firewall, you need to allow sufficient clearance around the device. Consider the following:

  • For the operating temperature of the services gateway to be optimal, the airflow around the chassis must be unrestricted.

  • For service personnel to remove and install hardware components, there must be adequate space at the front and back of the device. Allow at least 24 in. (61 cm) both in front of and behind the device.

  • If you are mounting the device in a rack with other equipment, or if you are placing it on the desktop near other equipment, ensure that the exhaust from other equipment does not blow into the intake vents of the chassis.

For information on the airflow through the chassis, see SRX320 Cooling System.

Rack Requirements

When installing the services gateway in a rack, you must ensure that the rack complies with a 1U (19 in. or 48.7 cm) rack as defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310-D), published by the Electronic Industries Alliance (

When selecting a rack, ensure that the physical characteristics of the rack comply with the following specifications:

  • The outer edges of the mounting brackets extend the width of either chassis to 19 in. (48.3 cm).

  • The front of the chassis extends approximately 0.5 in. (1.27 cm) beyond the mounting ears.

  • Maximum permissible ambient temperature when two devices are placed side by side in a 19 in. rack is 40° C.

The spacing of the mounting brackets and flange holes on the rack and device mounting brackets are as follows:

  • The holes within each rack set are spaced at 1 U (1.75 in. or 4.5 cm).

  • The mounting brackets and front-mount flanges used to attach the chassis to a rack are designed to fasten to holes spaced at rack distances of 1 U (1.75 in.).

  • The mounting holes in the mounting brackets provided with the device are spaced 1.25 in. (3.2 cm) apart (top and bottom mounting hole).

Always secure the rack in which you are installing the services gateway to the structure of the building. If your geographical area is subject to earthquakes, bolt the rack to the floor. For maximum stability, also secure the rack to ceiling brackets.

Cabinet Requirements

You can install the services gateway in a 19 in. (48.7 cm) cabinet as defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310-D) published by the Electronic Industries Alliance ( You must mount the services gateway horizontally in the cabinet using appropriate rack adapters.

When selecting a cabinet, ensure that it meets the following specifications:

  • The cabinet is at least 1U (3.50 in. or 8.89 cm) and can accommodate the services gateway.

  • The outer edges of the mounting brackets extend the width of either chassis to 19 in. (48.7 cm), and the front of the chassis extends approximately 0.5 in. (1.27 cm) beyond the mounting brackets.

  • The minimum total clearance inside the cabinet is 30.7 in. (78 cm) between the inside of the front door and the inside of the rear door.


A cabinet larger than the minimum required provides better airflow and reduces the chance of overheating.

When you mount the services gateway in a cabinet, you must ensure that ventilation through the cabinet is sufficient to prevent overheating. Consider the following when planning for chassis cooling:

  • Ensure that the cool air supply you provide through the cabinet can adequately dissipate the thermal output of the services gateway.

  • Install the services gateway as close as possible to the front of the cabinet so that the cable management system clears the inside of the front door. Installing the chassis close to the front of the cabinet maximizes the clearance in the rear of the cabinet for critical airflow.

  • Route and dress all cables to minimize the blockage of airflow to and from the chassis.