Catalyst 4948E and Catalyst 4948E-F Switch Installation Guide
Preparing for Installation
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Preparing for Installation

Table Of Contents

Preparing for Installation

Safety

Site Requirements

Rack-Mounting Guidelines

Temperature

Air Flow

Humidity

Altitude

Dust and Particulates

Corrosion

Electromagnetic and Radio Frequency Interference

Shock and Vibration

Power Source Interruptions

System Grounding

Maintaining Safety with Electricity

Preventing Electrostatic Discharge Damage

Power Requirements

Power Connection Guidelines for AC-Powered Systems

Power Connection Guidelines for DC-Powered Systems

Cabling Requirements

Site Preparation Checklist


Preparing for Installation


Revised: July 2012

Planning a proper location for the switch and the layout of your equipment rack or wiring closet is essential for successful system operation. Equipment placed too close together or inadequately ventilated can cause system overtemperature conditions. In addition, poor equipment placement can make network interface connections inaccessible and difficult to maintain.

This chapter describes how to prepare your site for switch installation and includes these sections:

Safety

Site Requirements

System Grounding

Power Requirements

Cabling Requirements

Site Preparation Checklist


Tip For additional information about the Cisco Catalyst 4948E or the Catalyst 4948E-F switch (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/ps6021/tsd_products_support_series_home.html


Safety

Safety warnings appear throughout this publication in procedures that may harm you if performed incorrectly. A warning symbol precedes each warning statement. The warnings below are general warnings that are applicable to the entire publication.


Warning Only trained and qualified personnel should be allowed to install, replace, or service this equipment. Statement 1030

Warning This unit is intended for installation in restricted access areas. A restricted access area can be accessed only through the use of a special tool, lock and key, or other means of security. Statement 1017

Warning Voltages that present a shock hazard may exist on Power over Ethernet (PoE) circuits if interconnections are made using uninsulated exposed metal contacts, conductors, or terminals. Avoid using such interconnection methods, unless the exposed metal parts are located within a restricted access location and users and service people who are authorized within the restricted access location are made aware of the hazard. A restricted access area can be accessed only through the use of a special tool, lock and key or other means of security. Statement 1072

Site Requirements

These following sections describe some of the basic site requirements that you should be aware of as you prepare to install your Catalyst 4948E or Catalyst 4948E-F switch:

Rack-Mounting Guidelines

Temperature

Air Flow

Humidity

Altitude

Dust and Particulates

Corrosion

Electromagnetic and Radio Frequency Interference

Shock and Vibration

Maintaining Safety with Electricity

Preventing Electrostatic Discharge Damage

Rack-Mounting Guidelines

A rack-mount kit (69-2037-xx) is included in the accessory kit for mounting the switch in a standard 19-inch (48.3 cm) equipment rack. This rack-mount kit is not suitable for use in the following situations:

Racks with obstructions (such as power strips) that could impair access to the switch

Before rack-mounting the switch, ensure the following:

The equipment rack is the proper size.

The width of the rack, between the two front-mounting strips or rails, must be 17.75 inches (45.09 cm).

The depth of the rack, between the front- and rear-mounting strips, must be at least 19.25 inches (48.9 cm) but not more than 32.5 inches (82.5 cm).

The rack must have sufficient vertical clearance to insert the chassis. The chassis height is 1 U (1.75 inches (4.45 cm)).

The equipment rack is stable and in no danger of falling over.

Ensure that the shelf is constructed to support the weight and dimensions of the chassis.

We recommend that you bolt the rack to the floor.

Mount the unit at the bottom of the rack if it is the only unit in the rack.

Install heavier equipment in the lower half of the rack to maintain a low center of gravity and prevent the rack from becoming top-heavy and tipping over.

Install the stabilizers before mounting or servicing the switch in the rack (if the rack is provided with stabilizing devices).

The equipment rack is properly ventilated.

Install the chassis in an enclosed rack only if it has adequate ventilation or an exhaust fan; use an open rack whenever possible.

Ensure that the ambient temperature of the rack environment does not exceed a maximum temperature of 104×F (40×C). If the switch is installed in a closed or multiunit rack assembly, the ambient operating temperature of the rack environment might be higher than the ambient room temperature.

Ensure that the ventilation system in a closed rack does not prevent cooling by creating negative pressure around the chassis and redirecting the air away from the chassis intake vent. If necessary, operate the chassis with the rack open.

Ensure that equipment installed near the bottom of a rack does not generate excessive heat, which can be drawn upward and into the air intakes of equipment above. This situation can cause overtemperature conditions in the chassis at or near the top of the rack.

Consider the equipment and cabling that is already installed in the rack. Ensure that cables from other equipment will not obstruct the airflow through the chassis or impair access to the power supplies or switching modules. Route cables away from field-replaceable components to avoid disconnecting cables unnecessarily for equipment maintenance or upgrades.

Allow at least 3 to 4 feet (91.4 to 121.9 cm) of clearance behind the rack for maintenance and removal of switch assemblies. If the rack is mobile, you can push it back within 1 foot (30.45 cm) of a wall or cabinet for normal operation and pull it out when necessary for maintenance.

Temperature

Temperature extremes can cause a system to operate at reduced efficiency and cause a variety of problems, including premature aging and failure of chips, and failure of mechanical devices. Extreme temperature fluctuations can cause chips to become loose in their sockets. Observe the following guidelines:

Ensure that the system is operating in an environment no colder than 50°F (10°C) or hotter than 104°F (40°C).

Ensure that the chassis has adequate ventilation.

Use proper air circulation management techniques. Chassis mounted higher in a rack enclosure are susceptable to higher ambient air temperatures due to the heat generated from chassis that are mounted below the chassis in the rack.

Do not place the chassis within a closed-in wall unit or on top of cloth, which can act as insulation.

Do not place the chassis where it will receive direct sunlight, particularly in the afternoon.

Do not place the chassis next to a heat source of any kind, including heating vents.

Ensure that all slots and openings on a chassis remain unobstructed, especially the fan tray vent at the back of the chassis. Adequate ventilation is particularly important at high altitudes where the air is thinner.

Clean the installation site at regular intervals to avoid buildup of dust and debris, which can cause a system to overheat.

Allow a 2-hour warm-up period to bring the chassis up to normal operating temperature before turning it on for chassis that have been exposed to abnormally cold temperatures.

Failure to observe these guidelines can damage internal chassis components.


Note The Catalyst 4948E and the Catalyst 4948E-F switches are equipped with internal air temperature sensors that are triggered above 104°F (40°C) generating a minor alarm and above 131°F (55°C) generating a major alarm. Enter the command show environment status to determine the exact temperature when the alarms are generated.


Air Flow

The Catalyst 4948E and Catalyst 4948E-F switches are designed to be installed in an environment where there is a sufficient volume of air available to cool the chassis and the power supplies. Any constraints placed on the free flow of air through the chassis or an elevated ambient air temperature can cause the switch to overheat and shut down.

To maintain proper air circulation through the switch chassis, we recommend that you maintain a minimum 6-inch (15 cm) separation between a wall and the chassis hot air exhaust. Failure to maintain adequate spacing between chassis can cause the switch chassis that is drawing in the hot exhaust air to overheat and fail.

If you are installing your Catalyst 4948E or Catalyst 4948E-F switch chassis in an enclosed or partially enclosed rack, we strongly recommend that you verify that your site meets the following guidelines:

Verify that the ambient air temperature within the enclosed or partially enclosed rack is within the chassis operating temperature limits. After installing the chassis in the rack, power up the chassis and allow the chassis temperature to stabilize (approximately 2 hours). Measure the ambient air temperature at the chassis air intake grill and at the chassis air exhaust grill by positioning an external temperature probe approximately 1 inch (2.5 cm) away from the grills.

If the ambient intake air temperature is less than 104°F (40°C), the rack meets the intake air temperature criterion.

If the ambient intake air temperature exceeds 104°F (40°C), the system might experience minor temperature alarms and is in danger of overheating.

If the ambient intake air temperature equals or is greater than 131°F (55°C), the system will experience a major temperature alarm and shut down.

Verify that the enclosed or partially enclosed rack allows an adequate flow of air through the switch chassis as follows:

If the difference between the measured intake air temperature and the exhaust air temperature does not exceed 10°C, there is sufficient airflow in the rack.

If the difference in air temperature exceeds 10°C, there is insufficient airflow to cool the chassis.


Note The 10°C temperature differential between the intake and the exhaust must be determined by taking measurements using external digital temperature probes. Do not use the chassis internal temperature sensors to measure the temperature differential.


Plan for future growth. Your Catalyst 4948E or Catalyst 4948E-F switches currently installed in an enclosed or partially enclosed rack might meet ambient air temperature and air flow requirements now. However, if you add more chassis or other equipment to the rack, the additional heat generated might cause the ambient air temperature within the rack to exceed 104°F (40°C) and can cause minor alarms.

If you are installing the Catalyst 4948E-F in a data center that uses the hot isle and cold isle style of cooling, we recommend that you use an optional inlet air duct to extend the chassis air intake to the cold isle. Panduit Corporation manufactures a Modular ToR Switch Inlet Duct (Model CDE2) that can be installed along with the Catalyst 4948E-F chassis to extend the switch chassis air intake to the cold isle at the front of the rack enclosure.

Humidity

High-humidity conditions can cause moisture migration and penetration into the system. This moisture can cause corrosion of internal components and degradation of properties such as electrical resistance, thermal conductivity, physical strength, and size. Extreme moisture buildup inside the system can result in electrical shorts, which can cause serious damage to the system. Each system is rated to operate at 8 to 80 percent relative humidity, with a humidity gradation of 10 percent per hour. In storage, a system can withstand from 5 to 95 percent relative humidity. Buildings in which climate is controlled by air-conditioning in the warmer months and by heat during the colder months usually maintain an acceptable level of humidity for system equipment. However, if a system is located in an unusually humid location, a dehumidifier can be used to maintain the humidity within an acceptable range.

Altitude

Operating a system at high altitude (low pressure) reduces the efficiency of forced and convection cooling and can result in electrical problems related to arcing and corona effects. This condition can also cause sealed components with internal pressure, such as electrolytic capacitors, to fail or perform at reduced efficiency. Each system is rated to operate at altitudes from -50 to 6500 feet (-16 to 1981 meters) and can be stored at altitudes of -50 to 35,000 feet (-16 to 10,668 meters).

Dust and Particulates

Fans cool the power supplies and the system components by drawing in room temperature air, circulating the air through the power supplies and the chassis, and exhausting the heated air out through various openings in the chassis. However, fans also ingest dust and other particulates, causing contaminant buildup on the fan blades and in the system. This can create a thermal blanket on components increasing the internal chassis temperature.

A clean operating environment can greatly reduce the negative effects of dust and other particulates. The standards listed below provide guidelines for acceptable working environments and acceptable levels of suspended particulate matter:

Network Equipment Building Systems (NEBS) GR-63-CORE

National Electrical Manufacturers Association (NEMA) Type 1

International Electrotechnical Commission (IEC) IP-20

Corrosion

Corrosion of system connectors is a gradual process that can eventually lead to intermittent failures of electrical circuits. The oil from a person's fingers or prolonged exposure to high temperature or humidity can corrode the gold-plated edge connectors and pin connectors on various components in the system. To prevent corrosion, avoid touching contacts on boards and cards, and protect the system from extreme temperatures and moist, salty environments.

Electromagnetic and Radio Frequency Interference

Electromagnetic interference (EMI) and radio frequency interference (RFI) from a system can adversely affect devices such as radio and television (TV) receivers operating near the system. Radio frequencies emanating from a system can also interfere with cordless and low-power telephones. Conversely, RFI from high-power telephones can cause spurious characters to appear on the system monitor. RFI is defined as any EMI with a frequency above 10 kilohertz (kHz). This type of interference can travel from the system to other devices through the power cable and power source or through the air like transmitted radio waves. The Federal Communications Commission (FCC) publishes specific regulations to limit the amount of EMI and RFI emitted by computing equipment. Each system meets these FCC regulations. To reduce the possibility of EMI and RFI, follow these guidelines:

Only operate the system with the chassis covers installed.

Ensure that an unused power supply bay has a metal cover plate installed.

Ensure that the screws on all peripheral cable connectors are securely fastened to their corresponding connectors on the back of the chassis.

Always use shielded cables with metal connector shells for attaching peripherals to the system.

When wires are run for any significant distance in an electromagnetic field, interference can occur between the field and the signals on the wires. This fact has two implications for the construction of plant wiring:

Bad wiring practice can result in radio interference emanating from the plant wiring.

Strong EMI, especially when it is caused by lightning or radio transmitters, can destroy the signal drivers and receivers in the chassis, and even create an electrical hazard by conducting power surges through lines into equipment.


Note To predict and remedy strong EMI, you may also need to consult experts in radio frequency interference (RFI).


If you use twisted-pair cable in your plant wiring with a good distribution of grounding conductors, the plant wiring is unlikely to emit radio interference. If you exceed the recommended distances, use a high-quality twisted-pair cable with one ground conductor for each data signal when applicable.


Caution Category 5e, Category 6, and Category 6a cables can store large levels of static electricity because of the dielectric properties of the materials used in their construction. Always ground the cables (especially in new cable runs) to a suitable and safe earth ground before connecting them to the module.

If the wires exceed the recommended distances, or if wires pass between buildings, give special consideration to the effect of a lightning strike in your vicinity. The electromagnetic pulse caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If you previously have had similar problems, you might want to consult experts in electrical surge suppression and shielding.

Shock and Vibration

Catalyst 4948E and Catalyst 4948E-F switches have been shock- and vibration-tested for operating ranges, handling, and earthquake standards to NEBS (Zone 4 per GR-63-Core). These tests have been conducted in earthquake environment and criteria, office vibration and criteria, transportation vibration and criteria, and packaged equipment shock.

Power Source Interruptions

Systems are especially sensitive to variations in voltage supplied by the AC power source. Overvoltage, undervoltage, and transients (or spikes) can erase data from memory or even cause components to fail. To protect against these types of problems, power cables should always be properly grounded. Also, place the system on a dedicated power circuit (rather than sharing a circuit with other heavy electrical equipment). In general, do not allow the system to share a circuit with any of the following:

Copy machines

Air conditioners

Vacuum cleaners

Space heaters

Power tools

Teletype machines

Laser printers

Facsimile machines

Any other motorized equipment

Besides these appliances, the greatest threats to a system power supply are surges or blackouts that are caused by electrical storms. Whenever possible, turn off the system and any peripherals, and unplug them from their power sources during thunderstorms. If a blackout occurs—even a temporary one—while the system is turned on, turn off the system immediately and disconnect it from the electrical outlet. Leaving the system on may cause problems when the power is restored; all other appliances left on in the area can create large voltage spikes that can damage the system.

System Grounding

You must install a NEBS-compliant system ground as part of the chassis installation process. Chassis installations that rely only on the AC third-prong ground are insufficient to properly and adequately ground the systems. Both chassis comes with a ground lug and two M4 bolts as part of the accessory kit. The lug attaches to the chassis grounding pad with the two bolts. A 6 AWG copper wire (not provided) must be used to connect the ground lug to the NEBS-compliant building ground.

Proper grounding practices ensure that the buildings and the installed equipment within them have low-impedance connections and low-voltage differentials between chassis. When you include NEBS-compliant system grounds, you reduce or prevent shock hazards, greatly reduce the chances of equipment damage due to transients, and substantially reduce the potential for data corruption.

Without proper and complete system grounding, you run the risk of increased component damage due to ESD. Additionally, you have a greatly increased chance of data corruption, system lockup and frequent system reboot situations by not using a system (NEBS compliant) ground.


Caution Installations that rely solely on system grounding using only an AC third-prong ground run a substantially greater risk of equipment problems and data corruption than those installations that use both the AC third-prong ground and a properly installed system (NEBS compliant) ground.

Table 2-1 lists some general grounding practice guidelines.

Table 2-1 Grounding Practice Guidelines 

Environment
Electromagnetic Noise Severity Level
Grounding Recommendations

Commercial building is subjected to direct lightning strikes.

For example, some places in the United States, such as Florida, are subject to more lightning strikes than other areas.

High

All lightning protection devices must be installed in strict accordance with manufacturer recommendations. Conductors carrying lightning current should be spaced away from power and data lines in accordance with applicable recommendations and codes. Best grounding practices must be closely followed.

Commercial building is located in an area where lightning storms frequently occur but is not subject to direct lightning strikes.

High

Grounding best practices must be closely followed.

Commercial building contains a mix of information technology equipment and industrial equipment, such as welding.

Medium to High

Grounding best practices must be closely followed.

Existing commercial building is not subject to natural environmental noise or man-made industrial noise. This building contains a standard office environment. This installation has a history of malfunction due to electromagnetic noise.

Medium

Grounding best practices must be closely followed. Determine source and cause of noise if possible, and mitigate as closely as possible at the noise source or reduce coupling from the noise source to the victim equipment.

New commercial building is not subject to natural environmental noise or man-made industrial noise. This building contains a standard office environment.

Low

Grounding best practices should be followed as closely as possible. Electromagnetic noise problems are not anticipated, but installing a best practice grounding system in a new building is often the least expensive route and the best way to plan for the future.

Existing commercial building is not subject to natural environmental noise or man-made industrial noise. This building contains a standard office environment.

Low

Grounding best practices should be followed as much as possible. Electromagnetic noise problems are not anticipated, but installing a best practice grounding system is always recommended.



Note In all situations, grounding practices must comply with Section 250 of the National Electric Code (NEC) requirements or local laws and regulations. A 6 AWG grounding wire is preferred from the chassis to the rack ground or directly to the common bonding network (CBN). The equipment rack should also be connected to the CBN with 6 AWG grounding wire.



Caution Category 5e, Category 6, and Category 6a cables can store large levels of static electricity because of the dielectric properties of the materials used in their construction. Always ground the cables (especially in new cable runs) to a suitable and safe earth ground before connecting them to the port on the switch.

Maintaining Safety with Electricity

When working on electrical equipment, follow these guidelines:

Do not work alone if potentially hazardous conditions exist anywhere in your work space.

Never assume that power is disconnected from a circuit; always check the circuit before working on it.

Look carefully for possible hazards in your work area, such as damp floors, ungrounded power extension cables, frayed or damaged power cords, and missing safety grounds.

If an electrical accident occurs, proceed as follows:

Use extreme caution; do not become a victim yourself.

Disconnect power from the system.

If possible, send another person to get medical aid. Otherwise assess the condition of the victim, and then call for help.

Determine if the person needs rescue breathing or external cardiac compressions; then take appropriate action.

Use the product within its marked electrical ratings and product usage instructions.

Install the product in compliance with local and national electrical codes.

If any of the following conditions occur, contact the Cisco Technical Assistance Center:

The power cable or plug is damaged.

An object has fallen into the product.

The product has been exposed to water or other liquids.

The product has been dropped or shows signs of damage.

The product does not operate correctly when you follow the operating instructions.

Use the correct external power source. Operate the product only from the type of power source indicated on the electrical ratings label. If you are not sure of the type of power source required, consult the Cisco Technical Assistance Center or a local electrician.

Use approved power cables only. You have been provided with one or more power cables with your chassis power supply that are intended for use in your country, based on the shipping location. Should you need to purchase additional power cables, ensure that they are rated for the product and for the voltage and current marked on the product's electrical ratings label. The voltage and current rating of the power cable should be greater than the ratings marked on the label.

To help prevent electrical shock, plug all power cables into properly grounded electrical outlets. These power cables are equipped with three-prong plugs to help ensure proper grounding. Do not use adapter plugs or remove the grounding prong from a power cable.

Observe power strip ratings. Make sure that the total current rating of all products that are plugged into the power strip does not exceed 80 percent of the power strip rating.

Do not modify power cables or plugs yourself. Consult with a licensed electrician or your power company for site modifications. Always follow your local and national wiring codes.

Preventing Electrostatic Discharge Damage

Electrostatic discharge (ESD) damage, which can occur when modules or other FRUs are improperly handled, results in intermittent or complete failures. Modules consist of printed circuit boards that are fixed in metal carriers. Electromagnetic interference (EMI) shielding and connectors are integral components of the carrier. Although the metal carrier helps to protect the board from ESD, always use an ESD grounding strap when handling modules.

To prevent ESD damage, follow these guidelines:

Always use an ESD wrist strap and ensure that it makes maximum contact with bare skin. ESD grounding straps are available with banana plugs, metal spring clips, or alligator clips. If you choose to use the disposable ESD wrist strap supplied with most FRUs or an ESD wrist strap equipped with an alligator clip, you must attach the system ground lug to the chassis in order to provide a proper grounding point for the ESD wrist strap.


Note This system ground is also referred to as the network equipment building system (NEBS) ground.


If your chassis does not have the system ground attached, you must install the system ground.

After you install the system ground lug, follow these steps to correctly attach the ESD wrist strap:


Step 1 Attach the ESD wrist strap to bare skin as follows:

a. If you are using the ESD wrist strap supplied with the FRUs, open the wrist strap package and unwrap the ESD wrist strap. Place the black conductive loop over your wrist and tighten the strap so that it makes good contact with your bare skin.

b. If you are using an ESD wrist strap equipped with an alligator clip, open the package and remove the ESD wrist strap. Locate the end of the wrist strap that attaches to your body and secure it to your bare skin.

Step 2 Grasp the spring or alligator clip on the ESD wrist strap and momentarily touch the clip to a bare metal spot (unpainted surface) on the rack. We recommend that you touch the clip to an unpainted rack rail so that any built-up static charge is then safely dissipated to the entire rack.

Step 3 Attach either the spring clip or the alligator clip to the ground lug screw as follows:

a. If you are using the ESD wrist strap that is supplied with the FRUs, squeeze the spring clip jaws open, position the spring clip to one side of the system ground lug screw head, and slide the spring clip over the lug screw head so that the spring clip jaws close behind the lug screw head.


Note The spring clip jaws do not open wide enough to fit directly over the head of the lug screw or the lug barrel.


b. If you are using an ESD wrist strap that is equipped with an alligator clip, attach the alligator clip directly over the head of the system ground lug screw or to the system ground lug barrel.


Caution For safety, periodically check the resistance value of the antistatic strap. The measurement should be between 1 and 10 megohm (Mohm).


Power Requirements

When preparing your site for the switch installation, follow these general requirements:

In systems configured with two power supplies, connect each of the two power supplies to a separate input power source. If you fail to do this, your system might be susceptible to total power failure due to a fault in the external wiring or a tripped circuit breaker.

To prevent a loss of input power, be sure that the total maximum load on each source circuit is within the current ratings of the wiring and breakers.

In some systems, you may decide to use an uninterruptible power supply (UPS) to protect against power failures at your site. Be aware when selecting a UPS that some UPS models that use ferroresonant technology can become unstable when operating with the power supplies which use power factor correction (PFC). This can cause the output voltage waveform to the switch to become distorted resulting in an undervoltage situation in the system.

Power Connection Guidelines for AC-Powered Systems

This section provides some basic guidelines for connecting the AC power supplies to the site power source:

Each chassis power supply should have a separate, dedicated branch circuit.

For North America:

The 300 W power supply requires a 15 A circuit.

For International:

Circuits should be sized according to local and national codes.

If you are using a 200/240 VAC power source in North America, the circuit must be protected by a two-pole circuit breaker.

The source AC outlet must be within 6 feet (1.8 meters) of the system and should be easily accessible.

The AC power receptacles used to plug in the chassis must be the grounding type. The grounding conductors that connect to the receptacles should connect to protective earth ground at the service equipment.

Power Connection Guidelines for DC-Powered Systems

This section provides the basic guidelines for connecting the Catalyst 4948E switch DC-input power supplies to the site power source:

All power connection wiring should conform to the rules and regulations in the National Electrical Code (NEC), as well as any local codes.

The DC return must remain isolated from the system frame and the chassis (DC-I).

For DC power cables, we recommend that you use commensurately rated, high-strand-count copper wire cable. Connection to the DC-input power supply requires one earth ground cable, one source DC (-), and one source DC return (+). The length of the cables depends on your switch location. The cables and the lugs required to attach the source DC cables to the power supply are not available from Cisco Systems. They are available from any commercial cable vendor.

The color coding of the source DC power cable leads depends on the color coding of the site DC power source. Typically, green or green and yellow indicate that the cable is a ground cable. Because there is no color code standard for source DC wiring, you must ensure that the power cables are connected to the DC-input power supply terminal block in the proper (+) and (-) polarity. In some cases, the source DC cable leads might have a positive (+) or a negative (-) label. This label is a relatively safe indication of the polarity, but you must verify the polarity by measuring the voltage between the DC cable leads. When making the measurement, the positive (+) lead and the negative (-) lead must always match the (+) and (-) labels on the DC-input power supply terminal block.

DC power cables must be terminated by cable lugs at the power supply end.

The circuit breaker is considered to be the disconnect device and should be easily accessible.

The circuit must be protected by a dedicated two-pole circuit breaker. The circuit breaker should be sized according to the power supply input rating and local or national code requirements.

Cabling Requirements


Caution The intrabuilding port(s) of the equipment or subassembly is suitable for connection to intrabuilding or unexposed wiring or cabling only. The intrabuilding port(s) of the equipment or subassembly must not be metallically connected to interfaces that connect to the Outside Plant (OSP) or its wiring. These interfaces are designed for use as intrabuilding interfaces only (Type 2 or Type 4 ports as described in GR-1089-CORE, Issue 4) and require isolation from the exposed OSP cabling. The addition of Primary Protectors is not sufficient protection to connect these interfaces metallically to OSP wiring.

When running power and data cables together in overhead cable trays or subfloor cable trays, be aware of the following caution:


Caution We strongly recommend that power cabling runs and other potential noise sources be located as far away as practical from LAN cabling that terminates on Cisco equipment. In situations, where this type of long parallel cable runs exist, which cannot be separated by at least 3.3 feet (1 meter), we recommend that you shield these potential noise sources. To avoid interference, the source should be shielded by housing it in a grounded metallic conduit.

Also be aware of the following caution concerning the use of Category 5e and Category 6 Ethernet cables:


Caution Category 5e, Category 6, and Category 6a cables can store large levels of static electricity because of the dielectric properties of the materials used in their construction. Always ground the cables (especially in new cable runs) to a suitable and safe earth ground before connecting them to the module.

Site Preparation Checklist

Table 2-2 lists the site planning activities that you should perform prior to installing the switch. Completing each activity helps ensure a successful switch installation.

Table 2-2 Site Planning Checklist 

Task No.
Planning Activity
Verified By
Time
Date

1

Space evaluation:

Space and layout

Floor covering

Impact and vibration

Lighting

Maintenance access

     

2

Environmental evaluation:

Ambient temperature

Humidity

Altitude

Atmospheric contamination

Airflow

     

3

Power evaluation:

Input power type

Power receptacles (Depends on power supply)1

Receptacle proximity to the equipment

Dedicated (separate) circuits for redundant power supplies

UPS for power failures2

DC systems: Proper gauge wire and lugs

     

4

Grounding evaluation:

Circuit breaker size

CO ground (AC- and DC-powered systems)

     

5

Cable and interface equipment evaluation:

Cable type

Connector type

Cable distance limitations

Interface equipment (transceivers)

     

6

EMI evaluation:

Distance limitations for signaling

Site wiring

RFI levels

     

1 Verify that each power supply installed in the chassis has a dedicated AC source or DC source circuit.

2 Refer to the power supply's kVA rating as a sizing criteria in determining the output required by the UPS. The power supply's kVA rating value is listed in the specifications table for each power supply in Appendix A.