Cisco Content Delivery Engine 205/220/250/280/285/420/460/470/475 Hardware Installation Guide

Preventing Electrostatic Discharge Damage

The CDEs have no user-serviceable parts inside their chassis. The only field-replaceable units are the AC and DC power supplies and storage drives.

Electrostatic discharge (ESD) damage, which can occur when drives, electronic cards, or components are improperly handled, results in complete or intermittent failures. Follow these advisories to prevent damage from ESD:

• Always use an ESD wrist or ankle strap and ensure that it makes good skin contact.
• Connect the equipment end of the strap to a bare metal, unpainted chassis surface.
• When removing or installing a component, use any available handles, ejector levers, or captive installation screws. These devices prevent accidental removal, provide proper grounding for the system, and help to ensure that bus connectors are properly seated.
• When unpacking a static-sensitive component from its shipping carton, do not remove the component from the antistatic packing material until you are ready to install the component in your system. Just before unwrapping the antistatic packaging, be sure to discharge static electricity from your body.
• When transporting a sensitive component, first place it in an antistatic container or packaging.
• Handle all sensitive components in a static-safe area. If possible, use antistatic floor pads and workbench pads.

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

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Environmental and Physical Specifications

The CDEs are tested to the environmental specifications indicated in Table 2-1 . All testing is performed per procedures defined in Bellcore GR-63-CORE NEBS Physical Protection and Bellcore GR-1089-CORE EMC and Electrical Safety—Generic Criteria for Network Telecommunications Equipment.

The CDE280 Engine should comply with CE Markings per directives 2004/108/EC and 2006/95/EC. For more information on the CDE280 specifications, see “CDE280 Specifications” section.

For information on the CDE285 specifications, see Cisco UCS C240 M4 Server Installation and Service Guide.

Table 2-2 provides the physical dimensions of the CDEs.

AC Power Option Warnings

These warnings apply only to CDEs with the AC power option.

Warning The device is designed to work with TN power systems. Statement 19

Warning Connect the device to a grounded power outlet. Statement 25

DC Power Option Warnings

These warnings apply only to CDEs with the DC power option.

Warning When stranded wiring is required, use approved wiring terminations, such as closed-loop or spade-type with upturned lugs. These terminations should be the appropriate size for the wires and should clamp both the insulation and conductor. Statement 1002

Warning Before performing any procedures, ensure that power is removed from the DC circuit. Statement 1003

Warning A readily accessible two-poled disconnect device must be incorporated in the fixed wiring. Statement 1022

Warning Use copper conductors only. Statement 1025

Warning When installing or replacing the unit, the ground connection must always be made first and disconnected last. Statement 1046

Emissions Disclaimer

This is an Federal Communications Commission (FCC) Class A device.

Intended Uses

This product was evaluated as Information Technology Equipment (ITE), which may be installed in central offices, telecommunication centers, network telecommunication facilities, offices, schools, computer rooms, and similar commercial type locations where the National Electric Code (NEC) applies. The suitability of this product for other product categories and environments (medical, industrial, telecommunications, residential, alarm systems, test equipment, and so on), other than an ITE application, may require further evaluation.

Caution Although CDEs accept both AC and DC power modules, the system does not allow mixing of AC and DC power modules in one system.

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If AC Power Supplies Are Installed

Source AC power disconnect: The AC power cord is considered the source disconnect for the CDE and must be readily accessible when installed. If the individual CDE power cords are not readily accessible for disconnection, you must install an AC power disconnect for the entire rack unit. This main disconnect must be readily accessible, and it must be labeled as controlling power to the entire rack, not just to the CDEs.

Grounding the rack installation— If the CDE power cord is plugged into an AC outlet that is part of the rack, you must provide proper grounding for the rack itself. When the CDE power cord is plugged into a wall AC outlet, the safety ground conductor in the power cord provides proper grounding only for the CDE. Take precaution when the CDE power cord is plugged into an AC outlet that is part of the rack. You must make sure that proper grounding on the rack power outlet is provided or provide proper grounding for the rack itself.

Note When installing the CDEs, use the provided AC power cords.

Supplemental Grounding Connection

A supplemental ground connection is provided on the CDEs in case it is intended for installation in a rack and connection to a Common Bonding Network (CBN) as defined by NEBS GR-1089. To ground the CDE to the rack when rack-mounted, connect an additional grounding conductor to the CDE by using the separate listed closed two-hole crimp lug having 5/8-inch pitch. It is recommended that the grounding conductor wire be number 12 to number 10 AWG, with green insulation, rated minimum167°F (75°C), low smoke fume (LSF) and flame retardant. The ground connections should be tightened to a torque of 6 to 8 in-lb.

Use a grounding conductor to ground a CDE205, CDE220 or CDE280. The grounding conductor consists of the following parts:

• 2 hex head screws
• 2 round head screws
• 2 flat washers
• 2 tooth lock washers
• 1 grounding tab

Perform the following steps to install the grounding conductor to the CDE205, CDE220 or CDE280:

Step 1 Screw the two round head screws along with the tooth lock washer to the side of the ground tab.

Step 2 Place the hook side of the grounding tab to the rear mesh of the chassis and secure it using the two hex head screws with the flat washers (see Figure 2-1). The top of the ground tab should be even with the rear I/O shield.

Figure 2-1 CDE220 Rear View

The CDE280 grounding conductor consists of two screws that are mounted on the rear of the chassis (see Figure 2-2).

Figure 2-2 CDE280 Rear View

For information about the CDE285 grounding connections, see Cisco UCS C240 M4 Server Installation and Service Guide.

For the CDE420 grounding conductor consists of two screws that are mounted on the rear of the chassis (see Figure 2-3).

Figure 2-3 CDE420 Rear View

Overcurrent protection: The CDE is designed for an AC line voltage source with up to 20 A of overcurrent protection per cord feed. If the power system for the equipment rack is installed on a branch circuit with more than 20 A of protection, you must provide supplemental protection for the CDE. The overall current rating of a configured CDE is less than 6 A.

If DC Power Supplies Are Installed

Connection with a DC source should only be performed by trained service personnel. The CDE with DC input is to be installed in a Restricted Access Location in accordance with articles 110-16, 110-17, and 110-18 of the National Electric Code, ANSI/NFPA 70. The DC source must be electrically isolated by double or reinforced insulation from any hazardous AC source. The DC source must be capable of providing up to 900 watts of continuous power per feed pair.

Caution Do not apply AC power to DC power modules.

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As a general rule, take precautions when preparing DC power cables for connection to the CDE. Make sure to strip the power conductor insulation so that when installed, no external bare copper is accessible at the terminal block. The torque required for the DC input terminal block connection on the power supplies is 5 to 7 in-lb. Take precautions when connecting the polarity. The DC power input terminals are marked as –48 V and RTN. The –48 V terminal is for the Negative (source DC –48 V or –60 V) and the RTN is for the Positive (source DC return). After power cables have been installed, be careful to avoid strain on the power connection. It is recommended that strain relief be provided as appropriate. For example, route the power cables in the rack and secure the cables with nylon tie wraps.

Source DC power disconnect— You are responsible for installing a properly rated DC power disconnect for the CDE system. This source disconnect must be readily accessible, and it must be labeled as controlling power to the CDE. The circuit breaker of a centralized DC power system may be used as a disconnect device when easily accessible and should be rated no more than 30 A.

Grounding the CDE— The ground connection must be made first and prior to powering the equipment. Each power module is provided with a ground connection using the 5-mm screw. The connection is to use a closed-loop lug and the screw is to be tightened to a torque of 6 to 8 in-lb. It is recommended that the ground wire be number 12 to number 10 AWG, with green/yellow insulation, rated minimum 167°F (75°C), low smoke fume (LSF) and flame retardant.

A supplemental ground connection is provided on the CDE in case it is intended for installation with an isolated DC return (DC-I) and is to be installed in a Common Bonding Network (CBN) per NEBS GR-1089. To reliably ground the CDE to the rack when rack-mounted, connect an additional grounding conductor to the CDE using the separate listed closed two-hole crimp lug having 5/8-inch pitch. It is recommended that the grounding conductor wire be number 12 to number 10 AWG, with green insulation, rated minimum 75°C (167°F), low smoke fume (LSF), and flame retardant. The ground connections should be tightened with a torque of 6 to 8 in-lb. The metal pin of each module near the input power connector is to be connected to a protective earthing conductor during final system assembly.

Overcurrent protection— Overcurrent protection circuit breakers must be provided as part of each host equipment rack and must be incorporated in the field wiring between the DC source and the CDE. The branch circuit protection should be connected to a 30 A UL listed circuit breaker (or suitably certified for the country used), rated minimum 75 VDC, and copper wire conductors, sized for 24 A current (12 AWG).

Temperature and Ventilation

The ambient temperature in which the CDE operates must not exceed the range established for each CDE type as defined in Appendix A, “Technical Specifications”. Extreme fluctuations in temperature can cause a variety of problems in your CDE.

To maintain proper cooling, the equipment rack must provide sufficient airflow to the front of the CDE. The rack selected and the ventilation provided must be suitable to the environment in which the CDE will be used. The rack must include ventilation sufficient to exhaust the rate heat load of each CDE server (see Table A-8 in Appendix A, “Technical Specifications” ).