Cisco CRS Carrier Routing System Multishelf System Site Planning Guide
Power and Cooling Requirements
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Table of Contents

Power and Cooling Requirements

Fabric Card Chassis Power System Overview

General Power and Grounding Requirements

Bonding and Grounding Guidelines

Power Cable Management

DC Power System

Fixed Configuration DC Power Requirements

Fixed Configuration DC Power Shelf Wiring

Modular Configuration DC Power Requirements

Modular Configuration DC Power Shelf Wiring

AC Power System

Fixed Configuration AC Power Requirements

Fixed Configuration AC Power Shelf Wiring

AC Delta Power Shelf Wiring

AC Wye Power Shelf Wiring

Modular Configuration AC Power Requirements

Modular Configuration AC Power Shelf Wiring

Converting 3-Phase AC to Single-Phase AC

Fabric Card Chassis Airflow

Power and Cooling Requirements

This chapter describes the power and cooling requirements for the Cisco CRS Carrier Routing System Fabric Card Chassis. It includes the following sections:


Note The multishelf system consists of LCCs and FCCs. This site planning guide describes the FCC and the mulitshelf system. See the Cisco CRS Carrier Routing System 16-Slot Line Card Chassis Site Planning Guide for specific LCC site planning information.


Fabric Card Chassis Power System Overview

The FCC power system consists of redundant power shelves, each powered by independent power sources. The FCC can be either AC or DC powered. There are two options for power systems: the fixed configuration power system and the modular configuration power system.

Fixed configuration power system consists of two power shelves, AC rectifiers or DC power entry modules (PEMs), and alarm modules. The AC version requires either 3-phase AC-Delta or 3-phase AC-Wye input power to the power shelves. In redundant configuration, the fixed configuration power system provides power sharing per power zone. The fixed configuration power system includes SNMP MIBS and XML support.

Modular configuration power system consists of two power shelves, AC or DC power modules (PMs), and alarm modules. However, unlike the fixed configuration power system, the AC version of the modular configuration power system requires single-phase AC input power to the power shelves; there is no 3-phase AC-Wye or AC-Delta. If you have 3-phase AC Delta or AC Wye at your equipment, a Cisco CRS 3-phase AC power distribution unit (PDU) will be required to convert 3-phase AC input power to single-phase AC input power for the power shelf. At the shelf level, the power system provides 2N redundancy; the PMs themselves provide load-share redundancy. The modular configuration power system also includes SNMP MIBS and XML support.


Note In a modular configuration AC power system, PDU refers to the Cisco CRS 3-phase AC PDU which is required to convert 3-phase AC-Wye or AC-Delta input power to single-phase AC input power for the modular configuration AC power shelf. For further information, refer to Cisco CRS 3-Phase AC Power Distribution Unit Installation Guide.



Note If you have a Cisco CRS 3-Phase AC PDU installed, either three or six AC PMs are required to be installed in each modular configuration AC power shelf to maintain a balanced 3-phase power load. If only three AC PMs are required in each power shelf, they must be installed in either slots 0, 1, 2 or slots 3,4,5.


Maximum input power requirements for the FCC with a fixed configuration power system installed are as follows:

  • DC-powered chassis requires up to a maximum of 9,473 watts (9.47 kW) of DC input power when the chassis is fully loaded.
  • AC-powered chassis requires up to a maximum of 11,363 watts (11.36 kW) of AC input power when the chassis is fully loaded.

Maximum input power requirements for the FCC with a modular configuration power system installed are as follows:

  • DC-powered chassis requires up to a maximum of 11,111watts (11.11 kW) of DC input power when the chassis is fully loaded.
  • AC-powered chassis requires up to a maximum of 10,870 watts (10.87 kW) of AC input power when the chassis is fully loaded.

Note These power requirements are for a fully loaded chassis. However, it is a good idea to allocate this much power for each chassis to ensure that enough power is available for future system expansion.


See Cisco CRS-1 Carrier Routing System Multishelf System Description for information about how each power system operates and distributes power to components in the chassis.

General Power and Grounding Requirements

This section describes the power and grounding requirements you must consider when planning the site facilities for the FCC. In addition, see the “DC Power System” section or the “Fixed Configuration AC Power Requirements” section for additional power requirements.


Note A certified electrician should review the information in these sections to ensure that the installation site meets these requirements. For larger system configurations, you may want to consult a facilities electrical expert to understand the load that the routing system may put on the facility power plant.


  • Installation of the FCC must follow national and local electrical codes:
  • In the United States—United States National Fire Protection Association (NFPA) 70 and United States National Electrical Code (NEC)
  • In Canada—Canadian Electrical Code, part I, CSA C22.1
  • In other countries—International Electrotechnical Commission (IEC) 60364, parts 1 through 7
  • Two separate and independent AC or DC power sources are needed to provide 2N redundancy for system power. Each power source requires its own circuit breaker.
  • Each power source must provide clean power to the site. If necessary, install a power conditioner.
  • The site must provide short-circuit (over-current) protection for devices.
  • Proper grounding is required at the site to ensure that equipment is not damaged by lightning and power surges. In addition:

For fixed and modular configuration AC-powered systems, a grounding-type AC power outlet is required. In addition, fixed and modular configuration AC-powered systems also require chassis grounding.

Chassis grounding is required for fixed and modular configuration DC-powered systems.

For fixed configuration DC-powered systems, each DC power shelf requires a connection to earth ground.

For modular configuration DC-powered systems, each DC power shelf is grounded by installing an external grounding bracket between the power shelves and attached to the chassis.

  • Site power planning must include the power requirements for any external terminals and test equipment you will use with your system.

Note Be sure to review the safety warnings in Regulatory Compliance and Safety Information for the Cisco CRS-1 Carrier Routing System before attempting to install the routing system.


Bonding and Grounding Guidelines

The FCC has a safety earth ground connection in conjunction with power cabling to the fixed configuration power shelves. The chassis also you to connect the central office ground system or interior equipment grounding system to the bonding and grounding receptacles on the router chassis, when either a fixed or modular configuration power system is installed. These grounding points are sometimes referred to as network equipment building system (NEBS) bonding and grounding studs.

Two threaded ground inserts are located on top of the chassis rear (OIM) side panel to the left of the lower power shelf

Two sets of grounding points are provided on top of the chassis rear (OIM) side panel and two sets of supplementary grounding points are provided at the bottom of the chassis on the rear (OIM) side of the chassis. Although you can use both grounding points in a set if you want, only one is needed for NEBS grounding purposes.


Note The NEBS bonding and grounding points are provided to satisfy the Telcordia NEBS requirements for supplemental bonding and grounding connections.


The grounding points are beneath a cover plate. When the cover plate is removed, you will be able to see the labels showing the location of the grounding points.

Figure 3-1 shows the NEBS and grounding points on the rear of the FCC with a fixed configuration power system installed. The location of the NEBS bonding an grounding points is the same on a chassis with a modular configuration power system installed.

Figure 3-1 NEBS Bonding and Grounding Points

 

Figure 3-2 shows the grounding points located at the top of the chassis on the rear (OIM) side with a modular configuration DC power system installed.

Figure 3-2 NEBS Bonding and Grounding Points—Modular Configuration DC Power Shown

 

 

1

Chassis ground cable

2

NEBS bonding and grounding points (fixed and modular configuration power)

3

NEBS bonding and grounding points (fixed configuration power only)


Note A 45-degree grounding lug is shown in Figure 3-2. A 180-degree (straight) grounding lug can also be used.



Note Two NEBS bonding and grounding points are provided. Only the top grounding point can be used if modular configuration power shelves are installed.


To connect the chassis to a supplemental ground connection, you must have the following:

  • One grounding lug that has two M6 bolt holes with 0.63 inch (5/8 inch) (1.60 cm) of spacing between them and a 6-AWG or larger multistrand copper cable.
  • The grounding lug used can be either a 180-degree (straight) lug, as shown in Figure 3-3, or a 45-degree lug, as shown in Figure 3-4.

Figure 3-3 180-Degree (Straight) Chassis Ground Lug

 

Figure 3-4 45-Degree Chassis Ground Lug

 

  • Two M6 or equivalent hex head bolts with integrated locking washers are pre-installed on the chassis.
  • Ground cable. Although we recommend at least 6-AWG multistrand copper cable, the actual cable diameter and length depend on your router location and site environment. This cable is not available from Cisco Systems; it is available from any commercial cable vendor. The cable should be sized according to local and national installation requirements.

Power Cable Management

Following is a list of considerations for the multishelf system DC power cables:

  • Verify BDFB (battery distribution fuse board) or plant assignment locations (DC power input source).
  • Measure the distance from the BDFB to the equipment, and calculate voltage drop (follow office guidelines) to determine cable size.
  • Record to order power distribution cables.
  • Record to order correct size fuses for circuits.
  • Record to order correct size power lugs for distribution cables.

Following is a list of considerations for the multishelf system AC power cords:

  • Are AC power cords long enough to reach the chassis from the AC power outlet?
  • AC Power outlets should be easy to access.
  • Consider the routing of power cords from the AC power outlets to each chassis:

How will power cords be routed to the power outlets?

Will cables be routed above the chassis or beneath raised floors?

DC Power System

The FCC can be configured with either a fixed or modular configuration DC-input power subsystem. The chassis power system provides the necessary power for chassis components. Site power requirements differ, depending on the source voltage used.

Each DC powered chassis contains two fixed or modular configuration DC power shelves for 2N redundancy. The power shelves contain the input power connectors.

  • In the fixed configuration power system, each power shelf contains two DC PEMs. The power shelves and DC PEMs are field replaceable.
  • In the modular configuration power system, each shelf can contain up to six DC PMs. The power shelves and DC PMs are field replaceable.

Fixed Configuration DC Power Requirements

A fixed configuration DC-powered FCC contains two DC power shelves and four DC PEMs. Each power shelf contains two DC PEMs. Input power connections from the DC power source are made to terminals at the rear of each power shelf. The power shelves and power modules are field replaceable. Each power shelf and power module has its own circuit breaker.

Figure 3-5 shows the power zones on the front (SFC) side of a fixed configuration DC-powered FCC.

Figure 3-5 FCC Power Zones, Fixed Configuration DC-Powered Chassis (SFC) Side

 

Figure 3-6 shows the power zones on the rear (OIM) side of a fixed configuration DC-powered FCC.

Figure 3-6 FCC Power Zones, Fixed Configuration DC-Powered Chassis Rear (OIM) Side

 

 

Observe the following guidelines for DC-powered chassis. In addition, be sure to review the requirements in the “General Power and Grounding Requirements” section.

  • Each DC-powered chassis requires up to a maximum of 9,473 watts (9.47 kW) of DC input power when the chassis is fully loaded.
  • Two separate and independent power sources are required, each providing nominal –48/–60 VDC, 60 A service (four inputs per shelf).
  • All power connection wiring should conform to the rules and regulations in the National Electrical Code (NEC) and any local codes. In addition, make sure that the wiring conforms to any internal requirements at the installation site.
  • Each DC power source must comply with the safety extra-low voltage (SELV) requirements in UL 60950-1, CSA-C22.2 No. 60950-1, EN60950-1, AS/NZS 60950, and IEC60950-1.
  • A DC-powered system should be installed in a restricted access area in accordance with the National Electric Code, ANSI/NFPA 70.
  • All components in the area where DC input power is accessible must be properly insulated.
  • If it is not possible to rely on the identification of the earthed conductor in the DC mains supply, whereby the equipment is not provided with a two-pole disconnect device, then a two-pole disconnect device is to be provided external to the equipment.

Table 3-1 lists the fixed configuration DC input current and voltage specifications.

 

Table 3-1 DC Input Current and Voltage Information

Nominal input voltage

–48 VDC North America
–60 VDC European Community
(range: –42 VDC to –75 VDC)

Input line current

46 A maximum at –48 VDC
37 A maximum at –60 VDC
55 A maximum at –42 VDC (low voltage extreme)

Inrush current

168 A peak at 75 VDC
(maximum for 1 ms)

Fixed Configuration DC Power Shelf Wiring

Each wiring block on the DC power shelf contains two pairs of terminals, one positive and one negative, and is covered by a plastic block cover that snaps onto the power shelf and is secured by a screw. The requirements for DC input power and ground connections are as follows:

  • Each DC PEM requires two DC inputs of nominal –48/–60 VDC, 60 A service. Because each DC input consists of two pairs of cable leads, source DC (–) and source DC return (+), you need four wires (two pairs) for each PEM or 8 total wires (four pairs) for each power shelf. In addition, each power shelf requires one grounding cable.
  • All input power cables for the chassis should have the same wire gauge, and cable lengths should match within 10 percent of deviation.
  • For DC input power cables, use the appropriate wire gauge for –48/–60 VDC, 60 A service. We recommend that you use a commensurately rated, high-strand-count copper wire cable. This cable is not available from Cisco Systems; it is available from any commercial vendor. The length of the input power cables depends on the chassis location. The cables must be long enough to reach the chassis from the A and B power bus access points.

Caution A certified electrician must select the appropriate DC input power cable based on standard electrical practices, such as derating factors, wiring type, operating temperatures, and so on. The electrician must verify that the cable complies with the National Electrical Code (NEC) and local codes and any guidelines in effect at the installation site. At minimum, DC input power cables must be 6-AWG or heavier and rated for 90°C (194°F) temperature or higher.

  • Earth ground cable is required for each fixed configuration DC power shelf. We recommend that you use at least 6-AWG multistrand copper cable, which is available from any commercial cable vendor.

The ground cable lug should be dual hole and able to fit over M6 terminal studs at 0.63-inch (1.60 cm) centers (for example, Panduit part number LCD2-14A-Q or LCD2-14AH-Q). The cable lug is similar to the cable lug for the input DC power cable. (See Figure 3-7.)


Note When wiring the fixed configuration DC power shelf, be sure to attach the ground cable first. When removing the wiring, be sure to remove the ground cable last.


  • Each DC input power cable must be terminated by a cable lug at the power shelf. The cable lug must be dual hole and able to fit over M6 terminal studs at 0.63 inch (5/8 inch) (1.6 cm) centers. For example, you could terminate a 6-AWG power cable with a cable lug such as Panduit part number LCD2-14A-Q or equivalent. (See Figure 3-7.)

Figure 3-7 DC Input Power Cable Lug

 

The color coding of the DC input power cables depends on the color coding of the site DC power source. Typically, green or green and yellow indicates that the cable is a ground cable. Because no color code standard for the source DC wiring exists, you must ensure that the power cables are connected to the DC-input power shelf terminal studs in the proper positive (+) and negative (–) polarity.


Note If reverse polarity occurs, the DC power module circuit breaker trips.


Figure 3-8 shows DC input power connections at the rear of the power shelf. The ground cable is to the far left on the shelf. When wiring the power shelf, be sure to attach the ground cable first. When removing the wiring, be sure to remove the ground cable last.

Figure 3-8 DC Power Shelf Wiring

 

 

Modular Configuration DC Power Requirements

A modular configuration DC-powered FCC contains two DC power shelves. Each modular configuration DC power shelf is connected to up to six DC power inputs and contains up to six DC PMs that are field replaceable.

Observe the following guidelines for DC-powered chassis. In addition, be sure to review the requirements in the “General Power and Grounding Requirements” section.

  • Each DC-powered chassis requires up to a maximum of 11,111watts (11.11 kW) of DC input power when the chassis is fully loaded.
  • Two separate and independent power sources are required, each providing nominal –48/–60 VDC, 60 A service (six inputs per shelf).
  • Power shelf grounding is accomplished by installing an external ground bracket between the power shelves and attached to the chassis.
  • All power connection wiring should conform to the rules and regulations in the National Electrical Code (NEC) and any local codes. In addition, make sure that the wiring conforms to any internal requirements at the installation site.
  • Each DC power source must comply with the safety extra-low voltage (SELV) requirements in UL 60950-1, CSA-C22.2 No. 60950-1, EN60950-1, AS/NZS 60950, and IEC60950-1.
  • A DC-powered system should be installed in a restricted access area in accordance with the National Electric Code, ANSI/NFPA 70.
  • All components in the area where DC input power is accessible must be properly insulated.
  • If it is not possible to rely on the identification of the earthed conductor in the DC mains supply, whereby the equipment is not provided with a two-pole disconnect device, then a two-pole disconnect device is to be provided external to the equipment.

Table 3-2 lists the modular configuration DC input current and voltage specifications.

 

Table 3-2 DC Input Current and Voltage Information

Nominal input voltage

–48 VDC North America
–60 VDC European Community
(range: –40 VDC to –72 VDC)

Input line current

50 A maximum at –48 VDC
40 A maximum at –60 VDC
60 A maximum at -40 VDC

Modular Configuration DC Power Shelf Wiring

Each modular configuration DC power shelf contains six pairs of double-stud terminals, covered by a plastic terminal block cover. To provide 2N power redundancy, one power shelf should be connected to the central office “A” power bus and the other power shelf should be connected to the “B” power bus.

The requirements for the modular configuration DC input power connections are as follows:

  • Each power shelf requires up to six pairs of cable leads, source DC (–) and source DC return (+), depending on the number of DC PMs installed.
  • All input power cables for the chassis should have the same wire gauge, and cable lengths should match within 10 percent of deviation.
  • For DC input power cables, use the appropriate wire gauge for –48/–60 VDC, 60 A service. We recommend that you use a commensurately rated, high-strand-count copper wire cable. This cable is not available from Cisco Systems; it is available from any commercial vendor. The length of the input power cables depends on the chassis location. The cables must be long enough to reach the chassis from the A and B power bus access points.

Caution A certified electrician must select the appropriate DC input power cable based on standard electrical practices, such as derating factors, wiring type, operating temperatures, and so on. The electrician must verify that the cable complies with the National Electrical Code (NEC) and local codes and any guidelines in effect at the installation site. At minimum, DC input power cables must be 6-AWG or heavier and rated for 90°C (194°F) temperature or higher.

  • Each DC input power cable is terminated at the power shelf by a cable lug. The power system terminal block lug opening width is 0.63 inch (1.6 cm). The terminal posts are centered 0.63 inches (1.6 cm) apart and are M6-threaded. We recommend that you use an appropriately sized 180-degree angle (straight) industry standard dual-hole, standard barrel compression lug,. For example, you could terminate a 6-AWG power cable with a cable lug such as Panduit part number LCD2-14A-Q or equivalent. (See Figure 3-9.)

Figure 3-9 DC Power Cable Lug

 

Figure 3-10 shows the DC input power cables connected to the modular configuration DC power shelf terminal studs.

Figure 3-10 Modular Configuration DC Power Shelf Cable Connections

 

AC Power System

The FCC can be configured with either a fixed or modular configuration AC-input power subsystem. The chassis power system provides the necessary power for chassis components. Site power requirements differ, depending on the source voltage used.

Each AC powered chassis contains two AC power shelves for 2N redundancy. The power shelves contain the input power connectors.

  • In the fixed configuration power system, each power shelf contains three AC-to-DC rectifiers. The power shelves and AC-to-DC rectifiers are field replaceable.
  • In the modular configuration power system, each shelf can contain up to six AC PMs. The power shelves and AC PMs are field replaceable.

Fixed Configuration AC Power Requirements

A fixed configuration AC-powered FCC contains two AC power shelves for 2N redundancy and three AC rectifiers per power shelf. The power shelves contain the input power connectors. The AC rectifiers convert the input 200-to-240 VAC power to 54.5 VDC used by the chassis. Each AC-powered chassis requires up to a maximum of 11,363 watts (11.36 kW) of AC input power when the chassis is fully loaded.

The AC rectifiers used in the FCC and LCC are identical, but they are programmed to provide the different power requirements for each type of chassis. Each power shelf and rectifier has its own circuit breaker. For additional power system details, see Cisco CRS-1 Carrier Routing System Multishelf System Description .

Figure 3-11 shows the power zones on the front (SFC) side of a fixed configuration AC-powered FCC.

Figure 3-11 FCC Power Zones, Fixed Configuration AC-Powered Chassis Front (SFC) Side

 

Figure 3-12 shows the power zones on the rear (OIM) side of a fixed configuration AC-powered FCC.

Figure 3-12 FCC Power Zones, Fixed Configuration AC-Powered Chassis (OIM Side)

 

Two versions of the AC power shelf are available for AC input power in either the Delta or Wye configuration. Each power shelf has a different Cisco part number to distinguish it from the other. All chassis have two power shelves of the same type; that is, two Delta or two Wye power shelves.

  • AC Wye power shelf has a Wye 3-phase, 5-wire connection: 200 to 240 (L-N)/346 to 415 (L-L) VAC, 50 to 60 Hz, A. For redundant operation, two 3-phase Wye 32-A branch circuits are required. One power connection is required for each power shelf. The 5-wire connection is 3 wire + neutral + protective earthing, or ground wire (3W+N+PE).
  • AC Delta power shelf has a Delta 3-phase, 4-wire connection: 200 to 240 VAC, 3-phase, 50 to 60 Hz, 32 A. For redundant operation, two 3-phase Delta 60-A branch circuits are required. One power connection is required for each power shelf. The 4-wire connection is 3 wire + protective earthing, or ground wire (3W+PE).

Cable accessory packages for the AC power shelves contain AC power cables for the power shelves. The power cables, which are 13 feet (4 meters) long, are not shipped preattached to the power shelves.

  • The Wye power cord is rated for 415 VAC, 40 A (North America) or 32 A (International). The power cord has a 5-pin 532P6W plug (3W+N+PE) that plugs into a similarly rated 532R6W power receptacle. (See Figure 3-13.)
  • The Delta power cord is rated for 250 VAC, 60 A. The power cord has a 4-pin 460P9W plug (3W+PE) that plugs into a 460R9W power receptacle. (See Figure 3-14.)

Figure 3-13 AC Wye Power Cord Plug

 

Figure 3-14 AC Delta Power Cord Plug

 

Fixed Configuration AC Power Shelf Wiring

The FCC can be ordered with AC power shelves in either the Delta or Wye configuration. Both types of power system modules require 3-phase, 220-to-240 VAC input power.

  • The AC Delta configuration is typically used in the United States, Japan, and other countries where the phase-to-phase voltage is approximately 208 VAC. The power supplies are wired between the phases (see Figure 3-15) and a neutral is not required.
  • The AC Wye configuration is typically used in Europe and countries where each phase-to-neutral voltage is approximately 220 VAC. The power supplies are wired between each phase and neutral (see Figure 3-16).

AC Delta Power Shelf Wiring

Figure 3-15 shows the wiring for the AC Delta power shelf. As shown, Delta has four wires (three phases and a safety ground) wired into a terminal board (TB1) on the power shelf. The power supplies are wired between the phases; therefore, a neutral is not required.

AC input power is routed through a circuit breaker (CB1) to the three 4.4-kW AC rectifiers (A0, A1, and A2), where it is converted into DC power and routed to power zones in the FCC:

  • A0 provides –54.5 VDC, 40 A output to power zones 1 and 3.
  • A1 provides –54.5 VDC, 26 A output to power zone 2.
  • A2 provides –54.5 VDC, 26 A output to power zone 4.

The chassis power zones distribute power to the various components in the chassis through the backplane. Power system status signals are also routed to an alarm and service processor for system communication. See Cisco CRS-1 Carrier Routing System Multishelf System Description for information about the power zones in the FCC.

Figure 3-15 AC Delta Power Shelf Wiring

 


Note The same AC rectifiers are used in both the LCC and FCC; however, the AC power shelves are slightly different. In the FCC, a jumper on the AC power shelf backplane limits A1 and A2 current to 26 A. In the LCC, no jumper exists, and so A1 and A2 current is 40 A.


AC Wye Power Shelf Wiring

Figure 3-16 shows the wiring for the AC Wye power shelf. As shown, Wye has 5 wires (three phases, neutral, and a safety ground) wired into a terminal board (TB1) on the power shelf.

AC input power is routed through a circuit breaker (CB1) to the three 4.4-kW AC rectifiers (A0, A1, and A2), where it is converted into DC power and distributed to power zones in the FCC:

  • A0 provides –54.5 VDC, 40 A output to power zones 1 and 3.
  • A1 provides –54.5 VDC, 26 A output to power zone 2.
  • A2 provides –54.5 VDC, 26 A output to power zone 4.

The chassis power zones distribute power to the various components in the chassis through the backplane. Power system status signals are also routed to an alarm and service processor for system communication. See Cisco CRS-1 Carrier Routing System Multishelf System Description for information about the power zones in the FCC.

Figure 3-16 AC Wye Power Shelf Wiring

 


Note The same AC rectifiers are used in both the LCC and FCC; however, the AC power shelves are slightly different. In the FCC, a jumper on the AC power shelf backplane limits A1 and A2 current to 26 A. In the LCC, no jumper exists, and so A1 and A2 current is 40 A.


Modular Configuration AC Power Requirements

A modular configuration AC-powered FCC contains two AC power shelves and up to six AC PMs per power shelf.

In addition to the requirements in the “General Power and Grounding Requirements” section, AC input power requirements are as follows:

  • An AC-powered chassis requires up to a maximum of 10,870 watts (10.87 kW) of AC input power when the chassis is fully loaded.
  • Two separate and independent AC power sources are required, one for each power shelf. Each power shelf should be connected to a different power source to provide 2N power redundancy in case a power source fails.
  • Each AC power source must provide single-phase AC power, and have its own circuit breaker.
  • 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.
  • AC single-phase input:

Single-phase, 200 to 240 VAC nominal, 50 to 60 Hz, 16 A International and 20 A North America.

Each AC power shelf contains six IEC-320-C22 receptacles which can accept up to six IEC-320-C21 connector female cords, depending on how many AC PMs are installed in the shelf.

  • If it is not possible to rely on the identification of the earthed conductor in the AC mains supply, whereby the equipment is not provided with a two-pole disconnect device, then a two-pole disconnect device is to be provided external to the equipment.
  • Unlike the fixed configuration AC power system, which requires 3-phase AC Delta or AC Wye input power, the modular configuration AC power system requires single-phase AC input power. If you have 3-phase AC Delta or AC Wye at your equipment, a Cisco CRS 3-phase AC PDU will be required to convert 3-phase AC input power to single-phase AC input power for the power shelf. For further information, refer to Cisco CRS 3-Phase AC Power Distribution Unit Installation Guide.

Note If you have a Cisco CRS 3-phase AC PDU installed, either three or six AC PMs are required to be installed in each modular configuration AC power shelf to maintain a balanced 3-phase power load. If only three AC PMs are required in each power shelf, they must be installed in either slots 0, 1, 2 or slots 3,4,5.


For detailed modular configuration AC power specifications, see the “Modular Configuration Power Specifications” section.

Modular Configuration AC Power Shelf Wiring

The modular configuration AC power shelf is shipped with AC power cords. Each modular configuration AC power shelf accepts up to six power cords. Each power cord is 14 feet (4.25 m) in length with different plug types (pre-attached) available, depending on the locale. AC cords are available for the following locales:

  • North America
  • Europe
  • United Kingdom
  • Italy
  • Australia

Table 3-3 lists the single-phase AC-input cord power options and Cisco product numbers for the FCC with modular configuration AC power shelves installed. Table 3-3 also references power cord illustrations.

 

Table 3-3 Modular Configuration Single-Phase AC-Input Power Cord Options

Locale
Cisco Product Number
Plug Rating
Reference Illustration

North America

CRS-AC-CAB-NA(=)

20 A/250 VAC

Figure 3-17

Europe

CRS-AC-CAB-EU(=)

16 A/250 VAC

Figure 3-18

United Kingdom

CRS-AC-CAB-UK(=)

13 A/250 VAC

Figure 3-19

Italy

CRS-AC-CAB-IT(=)

16 A/250 VAC

Figure 3-20

Australia

CRS-AC-CAB-AU(=)

15 A/250 VAC

Figure 3-21

Figure 3-17 North America—Modular Configuration AC-Input Power Cord

 

Figure 3-18 Europe—Modular Configuration AC-Input Power Cord

 

Figure 3-19 United Kingdom—Modular Configuration AC-Input Power Cord

 


Note The BS-1363 standard rates cord sets up to a maximum of 13 A, 250 VAC for the C-21 plug. Therefore, the building circuit breaker must be 13 A maximum. Installation of the FCC must follow national and local electrical codes.


Figure 3-20 Italy—Modular Configuration AC-Input Power Cord

 

Figure 3-21 Australia—Modular Configuration AC-Input Power Cord

 


Note The AS 3112 standard rates cord sets up to a maximum of 15 A, 250 VAC for the C-21 plug. Therefore the building circuit breaker must be 15 A maximum. Installation of the FCC must follow national and local electrical codes.


Converting 3-Phase AC to Single-Phase AC

If you have 3-phase AC Delta or AC Wye input power at your equipment, a Cisco CRS 3-phase AC PDU will be required to convert 3-phase AC Delta or AC Wye input power to single-phase AC input power that connects directly to the rear of the modular configuration AC power shelf. The PDU includes either an AC Delta or AC Wye power interface, and has power input and power output cords entering and exiting the box.

There are two versions of the PDU for FCC available:

  • CRS-16-PDU-Delta—Redundant 3-phase to single-phase Delta PDU for FCC, 4 input/12 output
  • CRS-16-PDU-Wye—Redundant 3-phase to single-phase Wye PDU for FCC, 2 input/12 output

In addition to the requirements in the “General Power and Grounding Requirements” section, AC input power requirements are as follows:

  • Two separate and independent AC power sources are required, one for each PDU. Each PDU should be connected to a different power source to provide 2N power redundancy in case a power source fails.
  • Each AC power source must provide 3-phase VAC power, and have its own circuit breaker.
  • AC Delta input:

3-phase, 200 to 240 VAC (phase-to-phase), 50 to 60 Hz.

Input current: 2 x 27.7A.

Each PDU has two Delta input power cords preattached, each with a 4-pin IEC 60309 plug (3 wire + protective earthing [3W+PE]). The power cord is rated for 250 VAC, 60 A, and plugs into a similarly rated IEC 60309 receptacle.

Each PDU has six single phase output cords preattached, each with a 90 degree IEC-320-C21 female plug that plugs into a IEC-320-C22 inlet on the rear of the modular configuration AC power shelf.

  • AC Wye input:

3-phase, 200 to 240 VAC (phase-to-neutral), 50 to 60 Hz.

Input current: 32 A.

Each PDU has one Wye input power cord preattached, with a 5-pin IEC 60309 plug (3 wire + neutral + protective earthing conductor (ground wire) [3W+N+PE]). The cord is rated for 415 VAC, 16 A, and plugs into a similarly rated IEC 60309 receptacle.

Each single PDU has six single phase output cords preattached, each with a 90 degree IEC-320-C21 female plug that plugs into a IEC-320-C22 inlet on the rear of the modular configuration AC power shelf.

  • Grounding-type AC power outlet is required. The PDUs are shipped with AC power cords that have a grounding-type plug. As a safety feature, the plugs fit only a grounding-type AC power outlet.

Figure 3-22 and Figure 3-23 show the plugs for the power cords on the AC Delta and AC Wye PDUs.

Figure 3-22 AC Delta Power Cord Plug

 

Figure 3-23 AC Wye Power Cord Plug

 

For detailed PDU AC power specifications, see the Cisco CRS 3-Phase AC Power Distribution Unit Installation Guide.

Fabric Card Chassis Airflow

The airflow through the FCC is controlled by a push-pull configuration. Figure 3-24 shows the airflow through the FCC.

Figure 3-24 Airflow Through FCC

 

 

1

Front (SFC) side of chassis

6

Power shelves (two)

2

Air intake

7

Air exhaust

3

Lower fan tray

8

Upper card cage

4

Air filter

9

Lower card cage

5

Upper fan tray

10

Rear (OIM) side of chassis

As shown in Figure 3-24, ambient air flows in at the bottom front of the FCC and up through the card cages until it exhausts at the top rear. The bottom fan tray pulls ambient air in from the bottom front of the chassis; the top fan tray pushes warm air out the back of the chassis. The power modules in the fixed configuration power shelves have their own self-contained cooling fans.

A replaceable air filter is positioned above the lower fan tray. How often the air filter should be replaced depends on the facility environment. In a dirty environment, or when you start getting frequent temperature alarms, you should always check the intake grills for debris, and then check the air filter to see if it needs replacement.

Before removing the air filter for replacement, you should have a spare filter on hand; then, when you remove the dirty filter, install the spare filter in the chassis.

The FCC has a maximum airflow of 2050 cubic feet per minute.