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Cisco CRS-1 Carrier Routing System 16-Slot Line Card Chassis System Description
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Preface
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Cisco CRS-1 Carrier Routing System
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Chassis Power System
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Chassis Cooling System
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Switch Fabric
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Modular Services Cards (MSCs) and Physical Layer Interface Modules (PLIMs)
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Route Processor
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Cable Management, System Interconnection, and BITS Support
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Control Plane
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Cisco CRS-1 Carrier Routing System 16-Slot Line Card Chassis Specifications
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Index
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Table Of Contents
Cisco CRS-1 16-Slot Chassis Power System
Cisco CRS-1 16-Slot Chassis Power System
This chapter describes the Cisco CRS-1 line card chassis power system. It contains the following sections:
Power specifications are provided in Appendix A, "Cisco CRS-1 Carrier Routing System 16-Slot Line Card Chassis Specifications."
Power System Overview
The Cisco CRS-1 16-slot line card chassis can be powered by either AC (Wye or Delta) or DC power. The power system takes the facility power and converts it to the DC voltage necessary to power chassis components. Both AC and DC power systems are fully redundant and contain the following components:
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Two (redundant) AC or DC power shelves
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Different power shelves are used for DC, AC Wye, and AC Delta input power. Each power shelf contains three AC rectifiers or three DC PEMs and an alarm module (Figure 2-1).
Figure 2-1 Power Shelf with Power Modules and Alarm Module
Power Architecture
AC and DC power systems use A and B power shelves to provide reliable, 2N redundant power to all chassis components. Figure 2-2 shows the power architecture and power distribution of a Cisco CRS-1 16-slot line card chassis.
Figure 2-2 Cisco CRS-1 16-Slot Line Card Chassis Power Distribution
As shown in Figure 2-2, AC or DC input power enters the chassis through the two power shelves and is distributed to the A or B power bus. Both bus bars distribute power through the midplane to the MSC, PLIM, switch fabric, RP, and fan controller card slots.
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Because chassis components are powered by both A and B power inputs, the Cisco CRS-1 16-slot line card chassis can continue to operate normally if:
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It takes two failures for the system to be degraded. In addition, the failures must occur in both the A and B sides of the power architecture and affect the same load zone for the degradation to occur.
Individual chassis components have power-related devices (OR-ing diodes, inrush control circuits, and EMI filters) that are part of the chassis power architecture. These power-related devices form part of the dual power source (A and B bus) architecture, and enable online insertion and removal (OIR) of the component, also called hot-swapping.
Chassis Load Zones
The AC or DC power system distributes power in the chassis through six load zones, which provide power redundancy and reliability. Each load zone receives power from both bus bars (A and B), which ensures that each card and module in the chassis is powered by both power shelves.
A Cisco CRS-1 16-slot line card chassis can lose a single power module or an entire power shelf and still have the power to operate. For a load zone to lose complete power, a power module in each power shelf would have to fail. Figure 2-3 shows the six load zones on the PLIM side of the Cisco CRS-1 16-slot line card chassis.
Figure 2-3 Cisco CRS-1 16-Slot Line Card Chassis Load Zones (PLIM Side)
As shown in Figure 2-3, each power module (DC PEM or AC rectifier) powers two load zones:
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Figure 2-3 also shows which load zones power which chassis slots:
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Figure 2-4 shows the six load zones on the MSC side of the Cisco CRS-1 16-slot line card chassis.
Figure 2-4 Cisco CRS-1 16-Slot Line Card Chassis Load Zones (MSC Side)
Figure 2-4 also shows which load zones power which chassis slots on the MSC side of the chassis:
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The fan trays (FT0 and FT1) receive their operating power from the fan controller cards (FC0 and FC1).
DC Power Systems
The Cisco CRS-1 16-slot line card chassis DC power system consumes 13,200 watts maximum when powering a full chassis. The DC power system, which provides 2N power redundancy for the routing system, contains the following components:
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DC Power Shelf
The DC power shelf is the enclosure that houses three DC power entry modules (PEMs), the alarm module, and power distribution connections and wiring. The power shelf (Figure 2-5) installs in the Cisco CRS-1 16-slot line card chassis from the front and plugs into the chassis power interface connector panel.
Figure 2-5 DC Power Shelf
The DC power shelf physical dimensions are:
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Each power shelf has six input power connectors to connect input DC power (nominal -48 VDC or
-60 VDC, 60A service). Each connector consists of two terminals (- and +). Each terminal consists of two M6 threaded studs, 0.6 inches long, and centered 0.625 inches apart. The terminals have a safety cover and there is strain relief on the power shelf to secure the input power cables.The power shelf also has a service processor that monitors the condition of each PEM and provides status signals that indicate the health of the power supplies.
Figure 2-6 is a block diagram of the connections between the DC power shelves and the Cisco CRS-1 16-slot line card chassis. See the Cisco CRS-1 Carrier Routing System 16-Slot Line Card Chassis Installation Guide for detailed information about the input power connections to the DC power shelf.
Figure 2-6 DC Power Shelves in a 16-Slot Line Card Chassis
Each DC power shelf supports three PEMs, and accepts two 60A battery feeds. Input DC power enters the power shelf and is processed by the PEMs before being distributed to the chassis midplane. The PEMs perform inrush current limiting, EMI filtering, surge protection, and circuit isolation on the input DC power, and then distribute the power to either the A or B bus bar in the chassis midplane.
To provide 2N redundancy, one DC power shelf powers the A bus and the other shelf powers the B bus. Load zones in the chassis midplane provide power from both the A and B bus to each card and module in the chassis. For detailed information about how power is distributed through the chassis, see the "Power Architecture" section and the "Chassis Load Zones" section.
The power shelf also has a service processor module that monitors the condition of each PEM and provides status signals to indicate the health of the power supplies (see the "PEM Indicators" section).
DC Power Entry Module
The DC power entry module (PEM), shown in Figure 2-7, processes input power from the power shelf and passes the power to the A or B bus bar. PEMs are field-replaceable.
Figure 2-7 DC Power Entry Module
The DC PEM physical dimensions are:
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Two -48 or -60 VDC inputs enter the PEM at the rear of the power shelf through a connector on the power shelf midplane. The PEM performs inrush current limiting, EMI filtering, surge protection, and circuit isolation to process the power before it exits the PEM and is distributed to the chassis midplane.
A service processor module (in the power shelf) monitors each PEM and reports the status to the system controller function on the route processor. The service processor detects whether the PEM is present, and monitors PEM output voltages and current, and fault and alarm conditions (see the "PEM Indicators" section).
Each PEM contains an ID EEPROM that stores information used by control software (for example, part number, serial number, assembly deviation, special configurations, test history, and field traceability data).
PEM Indicators
Each PEM has power and status indicators. PEM indicators are powered by both DC power shelves; therefore, the indicators are operational even when the PEM is not being powered from its input voltage. Table 2-1 lists the PEM status indicators and their functions. Table 2-2 lists the conditions of the LEDs under certain failure conditions.
AC Power Systems
The AC power system provides 13,200 watts to power the Cisco CRS-1 16-slot line card chassis. The AC power system, which provides 2N power redundancy for the routing system, contains the following components:
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Two versions of the 3-phase AC power shelf are available to support AC Delta or AC Wye input configurations. Each version of the AC power shelf has a different part number. The input AC power for each type of power shelf is as follows:
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AC Delta Power Shelf
The AC Delta power shelf is the enclosure that houses three AC rectifier modules, an alarm module, and power distribution connections and wiring. The AC Delta power shelf, shown in Figure 2-8, is installed in the Cisco CRS-1 16-slot line card chassis from the front and plugs into the chassis power interface connector panel.
Figure 2-8 AC Delta Power Shelf
The AC Delta power shelf physical dimensions are:
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Figure 2-9 illustrates the basic power architecture of an AC Delta powered Cisco CRS-1 16-slot line card chassis.
Figure 2-9 AC Delta Power Architecture
Input AC power enters the power shelf and is distributed to the three AC rectifiers in the shelf. The AC rectifiers convert AC power into DC power, provide filtering, and then pass the DC power to either the A or B bus bar in the chassis midplane.
To provide 2N redundancy, one AC power shelf powers the A bus and the other shelf powers the B bus. Load zones in the chassis midplane provide power from both the A and B bus to each card and module in the chassis. For detailed information about how power is distributed through the chassis, see the "Power Architecture" section and the "Chassis Load Zones" section.
The power shelf also has a service processor module that monitors the condition of each AC rectifier and provides status signals that indicate the health of the power supplies (see the "AC Rectifier Indicators" section).
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Figure 2-10 shows the wiring of an AC Delta power shelf. As shown, four-wire AC Delta 3-phase power is wired into the AC Delta power shelf at a terminal block (TB1). The 3-phase power is then routed through the shelf circuit breaker to the three AC rectifiers (PS0, PS1, and PS2) in the power shelf. The AC rectifiers convert the AC power into 54.5 VDC power for the chassis. Each AC rectifier powers two of the chassis load zones.
Figure 2-10 AC Delta Power Wiring
AC Wye Power Shelf
The AC Wye power shelf is the enclosure that houses three AC rectifier modules, an alarm module, and power distribution connections and wiring. The power shelf (Figure 2-11) is installed in the Cisco CRS-1 16-slot line card chassis from the front and plugs into the chassis power interface connector panel.
Figure 2-11 AC Wye Power Shelf
The AC Wye power shelf physical dimensions are:
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Figure 2-12 shows the basic power architecture of an AC Wye-powered Cisco CRS-1 16-slot line card chassis.
Figure 2-12 AC Wye Power Architecture
As shown in Figure 2-12, the 3-phase AC power is brought into the power shelf and distributed to the three AC rectifiers in the power shelf. The AC rectifiers convert the AC power into the DC power required by the chassis. The DC power is then routed to bus bars (A and B). The buses distribute the power through the midplane to the various cards and FRUs in the chassis.
One DC power shelf powers the A bus, and the other shelf powers the B bus. As shown, each card or FRU is powered from both the A and the B power buses. One entire power shelf could fail and the chassis would still be operational.
The power shelf also provides a means of monitoring the condition of each AC rectifier and providing status signals that indicate the health of the power supplies.
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Figure 2-13 shows the wiring of an AC Wye power shelf. As shown in Figure 2-10, 5-wire AC Delta 3-phase power is wired into the AC Wye power shelf at a terminal block (TB1). The 3-phase power is then routed through the shelf circuit breaker to the 3 AC rectifiers in the power shelf. The AC rectifiers (PS0, PS1, and PS2) convert the AC power into the DC (54.5 VDC) power. Each AC rectifier powers two of the chassis load zones. The DC power is distributed to the FRUs in the various load zones through the bus bar and the chassis midplane.
Figure 2-13 AC Wye Power Wiring
AC Rectifier
The AC rectifier is an AC power supply that converts input AC power into the DC power necessary to power chassis components. The same rectifier is used for both AC Wye and AC Delta power shelves.
The rectifier takes input AC power from the power shelf, rectifies the AC into DC, provides filtering and control circuitry, provides status signaling, and passes the DC power to either the A or B bus bar in the chassis midplane. Each AC rectifier has a self-contained cooling fan that draws air through the module.
Figure 2-14 AC Power Rectifier
The AC rectifier module physical dimensions are:
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As shown in Figure 2-13, a single phase of the 3-phase AC input power (200 to 240 VAC or 346 to 415 VAC) is routed to each AC power rectifier in the AC power shelf. The AC power enters the AC rectifier at the rear of the power shelf through a connector located on the power shelf midplane.
Once the power enters the AC rectifier, internal circuits rectify the AC into DC, filter and regulate it. The conversion from AC to DC is done in two stages. The first stage is for power factor correction (PFC). The PFC process converts the AC to 350 VDC power. The PFC maintains the AC input current to be sinusoidal and in-phase with the AC input. The result is near unity power factor. The second stage is DC-to-DC conversion. The DC-to-DC process converts the 350 VDC primary side power to -54.5 VDC isolated secondary power.
A service processor (SP) module in the power shelf monitors the status of each AC rectifier. The service processor communicates with the system controller on the route processor (RP). The service processor circuitry monitors the following AC rectifier fault and alarm conditions:
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Each AC rectifier contains an ID EEPROM that stores information used by control software (for example, part number, serial number, assembly deviation, special configurations, test history, and field traceability data).
AC Rectifier Indicators
Each AC rectifier has power and status indicators. The AC rectifier indicators receive power from both AC power shelves; therefore, the indicators are operational even when the AC rectifier is not powered from its input voltage.
Table 2-3 lists the AC rectifier status indicators and their functions. Table 2-4 lists the LED readings during failure conditions.
Alarm Module
Each AC or DC power shelf contains an alarm module that monitors the status of the power shelf and provides an external interface for system alarms. The same alarm module (Figure 2-15) is used in all power shelves.
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Figure 2-15 Alarm Module
The physical dimensions of the alarm module are:
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The alarm module performs the following functions:
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Table 2-5 lists the pin outs for the alarm relay connector.
Only Pins 1, 2, and 9 are available for customer use. The remaining pins are for Cisco manufacturing test, and should not be connected. Use a shielded cable for connection to this port for EMC protection.
