Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
ON THIS PAGE
 

QFX5240 Site Guidelines and Requirements

SUMMARY The proper function of the QFX5240 switch depends on you meeting certain environmental requirements, following site and wiring guidelines, and ensuring that your installation meets the grounding specifications and airflow clearance requirements that support QFX5240 switches.

QFX5240 Environmental Requirements and Specifications

You must install the switch in a rack and house it in a dry, clean, well-ventilated, and temperature-controlled environment.

Follow these environmental guidelines:

  • The site must be as dust-free as possible, because dust can clog air intake vents and filters, reducing the efficiency of the switch cooling system.

  • Maintain ambient airflow for normal switch operation. If the airflow is blocked or restricted, or if the intake air is too warm, the switch might overheat. As a result, the switch temperature monitor might shut down the device to protect the hardware components.

Table 1: QFX5240 Switch Environmental Tolerances

Description

Tolerance

Altitude

With DAC Cables: At 32° F through 104° F (0° C through 40° C), there is no performance degradation up to 6000 feet (1828.8 meters)

With Optics: At 32° F through 104° F (0° C through 40° C), Sea level

Relative humidity, operating

Normal operation ensured in relative humidity range of 5% through 90%, non-condensing

Temperature

  • Normal operation ensured in the temperature range of 32° F through 104° F (0° C through 40° C)

  • Nonoperating storage temperature in shipping container: –40° F through 158° F (–40° C through 70° C)

Seismic

Designed to comply with Zone 4 earthquake requirements in accordance with NEBS GR-63-CORE, Issue 3.

General Site Guidelines

Efficient device operation requires proper site planning and maintenance. It also requires proper layout of the equipment, rack or cabinet, and wiring closet.

To plan and create an acceptable operating environment for your device and prevent environmentally caused equipment failures:

  • Keep the area around the chassis free from dust and conductive material, such as metal flakes.

  • Follow the prescribed airflow guidelines to ensure that the cooling system functions properly. Ensure that exhaust from other equipment does not blow into the intake vents of the device.

  • Follow the prescribed electrostatic discharge (ESD) prevention procedures to prevent damaging the equipment. Static discharge can cause components to fail completely or intermittently over time.

  • Install the device in a secure area, so that only authorized personnel can access the device.

QFX5240 Grounding Cable and Lug Specifications

For installations that require a separate grounding conductor to the chassis, the switch must be adequately grounded before power is connected to ensure proper operation and to meet safety and electromagnetic interference (EMI) requirements.

To ensure proper operation and to meet safety and EMI requirements, you must connect a QFX5240 switch to earth ground before you connect power to the device.

Figure 1: Grounding a QFX5240 Switch Grounding a QFX5240 SwitchDo we need callouts on the illustration to show the grounding lug and connecting points?
Warning:

The switch is pluggable type A equipment that is installed in a restricted-access location. The switch has a separate protective earthing terminal provided on the chassis in addition to the grounding pin of the power supply cord. You must permanently connect this separate protective earthing terminal to earth ground for installations that require a separate grounding conductor to the chassis.
Warning:

To comply with GR-1089 requirements, ensure that all intrabuilding copper cabling used for SFP+ and QSFP+ ports are shielded and grounded at both ends.
CAUTION:

Before you install the switch, a licensed electrician must attach a cable lug to the grounding cables that you supply. See . A cable with an incorrectly attached lug can damage the switch.

Before connecting the switch to earth ground, review the following information:

QFX5240 Clearance Requirements for Airflow and Hardware Maintenance

When planning the site for installing a QFX5240, you must allow sufficient clearance around the installed chassis (see Figure 2).

Figure 2: Clearance Requirements for Airflow and Hardware Maintenance for a QFX5240 Switch Clearance Requirements for Airflow and Hardware Maintenance for a QFX5240 Switch

  • For the cooling system to function properly, the airflow around the chassis must be unrestricted. See QFX5240 Cooling System for more information about the airflow through the chassis.

  • If you are mounting a QFX5240 in a rack with other equipment, ensure that the exhaust from other equipment does not blow into the intake vents of the chassis.

  • Leave at least 24 in. (61 cm) both in front of and behind the QFX5240. For service personnel to remove and install hardware components, you must leave adequate space at the front and back of the switch. NEBS GR-63 recommends that you allow at least 30 in. (76.2 cm) in front of the rack and 24 in. (61 cm) behind the rack.

Site Electrical Wiring Guidelines

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

Warning:

You must provide a properly grounded and shielded environment and use electrical surge-suppression devices.

Avertissement Vous devez établir un environnement protégé et convenablement mis à la terre et utiliser des dispositifs de parasurtension.
Table 2: Site Electrical Wiring Guidelines

Site Wiring Factor

Guidelines

Signaling limitations

If your site experiences any of the following problems, consult experts in electrical surge suppression and shielding:

  • Improperly installed wires cause radio frequency interference (RFI).

  • Damage from lightning strikes occurs when wires exceed recommended distances or pass between buildings.

  • Electromagnetic pulses (EMPs) caused by lightning damage unshielded conductors and electronic devices.

Radio frequency interference

To reduce or eliminate RFI from your site wiring, do the following:

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

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

Electromagnetic compatibility

If your site is susceptible to problems with electromagnetic compatibility (EMC), particularly from lightning or radio transmitters, seek expert advice.

Strong sources of electromagnetic interference (EMI) can cause:

  • 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.

QFX5240 Rack Requirements

QFX5240 switches are designed to be installed on four-post racks.

Rack requirements consist of:

  • Rack type

  • Mounting bracket hole spacing

  • Rack size and strength

Table 3 provides the rack requirements and specifications for the QFX5240.

Table 3: Rack Requirements for the QFX5240

Rack Requirement

Guidelines

Rack type

Use a four-post rack that provides bracket holes or hole patterns spaced at 1-U (1.75 in. or 4.45 cm) increments and that meets the size and strength requirements to support the weight.

A U is the standard rack unit defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310–D) published by the Electronics Industry Association.

Mounting bracket hole spacing

The holes in the mounting brackets are spaced at 1-U (1.75 in. or 4.45 cm) increments, so that the switch can be mounted in any four-post rack that provides holes spaced at that distance.

Rack size and strength

  • Ensure that the rack complies with the standards for a 19-in. rack as defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310–D) published by the Electronics Industry Association.

  • A 900-mm rack as defined in the four-part Equipment Engineering (EE); European telecommunications standard for equipment practice (document numbers ETS 300 119-1 through 119-4) published by the European Telecommunications Standards Institute.

    The horizontal spacing between the rails in a rack that complies with this standard is usually wider than the device's mounting brackets, which measure 19 in. (48.26 cm) from outer edge to outer edge. Use approved wing devices to narrow the opening between the rails as required.

  • Ensure that the rack rails are spaced widely enough to accommodate the external dimensions of the switch chassis. The outer edges of the front-mounting brackets extend the width to 19 in. (48.26 cm).

  • For four-post installations, the front and rear rack rails must be spaced between 25.6 in. (65 cm) and 31.5 in. (80 cm) front to back.

  • The rack must be strong enough to support the weight of the switch.

  • Ensure that the spacing of rails and adjacent racks allows for proper clearance around the switch and rack.

Rack connection to building structure

  • Secure the rack to the building structure.

  • If earthquakes are a possibility in your geographical area, secure the rack to the floor.

  • Secure the rack to the ceiling brackets as well as wall or floor brackets for maximum stability.