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EX9251 Power System

 

Power Supplies in an EX9251 Switch

An EX9251 switch uses either AC or DC power supplies. You can install up to two power supplies in slots labeled 0 and 1 on the right side of the rear panel of the chassis. The power supply in EX9251 switches is a hot-insertable and hot-removable field-replaceable unit (FRU). You can install it without powering off the switch or disrupting the switching function.

The power supplies connect to the PEM board, which distributes the different output voltages produced by the power supplies to the switch components, depending on their voltage requirements. When both the power supplies are present, they share power almost equally within a fully populated system. If the first power supply in a redundant configuration fails or is removed, the second power supply assumes the entire electrical load without interruption. A single power supply provides the maximum configuration with full power for as long as the switch is operational. A second power supply can be installed for redundancy. The chassis is designed to support 1+1 feed redundancy.

Caution

Do not mix AC and DC power supplies in a switch.

Note

The switches are shipped with two power supplies pre-installed on the rear panel.

The power supplies are self-cooling units. Each power supply has its own built-in fan that cools the power supply.

AC Power Supply Description

Each AC power supply weighs approximately 2.2 lb (1 kg) and has a handle, an ejection lever, an AC appliance inlet, a fan, and LEDs to monitor the status of the power supply. Figure 1 shows the power supply.

Each power supply requires a dedicated AC power feed and a dedicated customer-site circuit breaker. We recommend that you use a minimum 20 A (110 VAC) or 16 A (220 VAC) customer-site circuit breaker, or as required by local code.

Warning

The switch is pluggable type A equipment installed in a restricted-access location. It has a separate protective earthing terminal (sized for 10-32 screws) on the rear panel of the chassis in addition to the grounding pin of the power supply cord. This separate protective earthing terminal must be permanently connected to earth.

Figure 1: AC Power Supply in an EX9251 Switch
AC Power Supply in an EX9251
Switch

AC Power Supply LEDs and Other Components

Figure 2 shows the LEDs and other components on an AC power supply without the AC power cord retainer installed.

Figure 2: LEDs and Other Components on an AC Power Supply Without the AC Power Cord Retainer Installed
LEDs and Other
Components on an AC Power Supply Without the AC Power Cord Retainer
Installed
  1
Handle
  4
Fault LED
  2
Input status LED
  5
Ejector lever
  3
Output status LED
  6
AC power cord retainer port

Figure 3 shows the LEDs and other components on an AC power supply with the AC power cord retainer installed.

Figure 3: LEDs and Other Components on an AC Power Supply With the AC Power Cord Retainer Installed
LEDs and Other Components on an AC Power Supply With the AC Power
Cord Retainer Installed
  1
Handle
  4
Fault LED
  2
Input status LED
  5
AC power cord retainer
  3
Output status LED
  6
Ejector lever

Table 1 describes the LEDs on the AC power supply.

Table 1: AC Power Supply LEDs

Label

Color

State

Description

AC OK

Unlit

Off

The power supply is disconnected from power source, or the power supply is not receiving power.

Green

On steadily

Power supply is receiving power.

DC OK

Unlit

Off

Power supply output is off.

Green

On steadily

The power supply is sending out power correctly.

! (Fault)

Amber

On steadily

An error is detected in the power supply. Replace the power supply as soon as possible. To maintain proper airflow through the chassis, leave the power supply installed in the chassis until you are ready to replace it.

Note

If the AC OK LED and the DC OK LED are unlit, either the AC power cord is not installed properly or the power supply fuse has failed. If the AC OK LED is lit and the DC OK LED is unlit, the AC power supply is installed properly, but the power supply has an internal failure.

DC Power Supply Description

Each DC power supply weighs approximately 2.2 lb (1 kg) and has a handle, an ejection lever, a fan, LEDs to monitor the status of the power supply, and a terminal block that provides a single DC input (–48 VDC and return) that requires a dedicated customer-site circuit breaker. We recommend that you use a dedicated customer-site circuit breaker rated for 25 A (–48 VDC) minimum, or as required by local code. If you plan to operate a DC-powered switch at less than the maximum configuration and do not provision a 25 A (–48 VDC) circuit breaker, we recommend that you provision a dedicated customer-site circuit breaker for each DC power supply rated for at least 125 percent of the continuous current that the system draws at –48 VDC.Figure 4 shows the power supply.

Warning

The switch is pluggable type A equipment installed in a restricted-access location. It has a separate protective earthing terminal (sized for 10-32 screws) on the rear panel of the chassis. This separate protective earthing terminal must be permanently connected to earth.

Figure 4: DC Power Supply in an EX9251 Switch
DC Power Supply in an EX9251
Switch

DC Power Supply LEDs and Other Components

Figure 5 shows the DC power supply status LEDs and other components on a DC power supply.

Figure 5: DC Power Supply LEDs and Other Components on a DC Power Supply
DC Power Supply LEDs
and Other Components on a DC Power Supply
  1
Input status LED
  3
Fault LED
  2
Output status LED
 
Caution

On the DC power supply, the V+ terminals are shunted internally together, as are the V– terminals. Terminal with the same polarity can be wired together from the same source to provide an additional current path in a higher power chassis. Do not connect the terminals to different sources.

Table 2 describes the LEDs on the DC power supply.

Table 2: DC Power Supply LEDs

Label

Color

State

Description

IN (Input)

Unlit

Off

The power supply is disconnected from power source, or the power supply is not receiving power.

Green

On steadily

Power supply is receiving power.

OUT (Output)

Unlit

Off

Power supply output is off.

Green

On steadily

The power supply is sending out power correctly.

! (Fault)

Amber

On steadily

An error is detected in the power supply. Replace the power supply as soon as possible. To maintain proper airflow through the chassis, leave the power supply installed in the chassis until you are ready to replace it.

AC Power Cord Specifications for an EX9251 Switch

Each AC power supply has a single AC appliance inlet located on the faceplate that requires a dedicated AC power feed. A detachable AC power cord is supplied with the AC power supply. The coupler is type C13 as described by International Electrotechnical Commission (IEC) standard 60320. The plug end of the power cord fits into the power source outlet that is standard for your geographical location.

Table 3 provides specifications and Figure 6 depicts the plug on the AC power cord for some of the countries or regions listed in Table 3.

Table 3: AC Power Cord Specifications

Country/Region

Electrical Specifications

Plug Standards

Juniper Model Number

Argentina

250 VAC, 10 A, 50 Hz

IRAM 2073 Type RA/3

CBL-EX-PWR-C13-AR

Australia

250 VAC, 10 A, 50 Hz

AS/NZZS 3112 Type SAA/3

CBL-EX-PWR-C13-AU

Brazil

250 VAC, 10 A, 50 Hz

NBR 14136 Type BR/3

CBL-EX-PWR-C13-BR

China

250 VAC, 10 A, 50 Hz

GB 1002-1996 Type PRC/3

CBL-EX-PWR-C13-CH

Europe (except Italy, Switzerland, and United Kingdom)

250 VAC, 10 A, 50 Hz

CEE (7) VII Type VIIG

CBL-EX-PWR-C13-EU

India

250 VAC, 10 A, 50 Hz

IS 1293 Type IND/3

CBL-EX-PWR-C13-IN

Israel

250 VAC, 10 A, 50 Hz

SI 32/1971 Type IL/3G

CBL-EX-PWR-C13-IL

Italy

250 VAC, 10 A, 50 Hz

CEI 23-16 Type I/3G

CBL-EX-PWR-C13-IT

Japan

125 VAC, 12 A, 50 Hz or 60 Hz

SS-00259 Type VCTF

CBL-EX-PWR-C13-JP

Korea

250 VAC, 10 A, 50 Hz or 60 Hz

CEE (7) VII Type VIIGK

CBL-EX-PWR-C13-KR

North America

125 VAC, 13 A, 60 Hz

NEMA 5-15 Type N5-15

CBL-EX-PWR-C13-US

South Africa

250 VAC, 10 A, 50 Hz

SABS 164/1:1992 Type ZA/13

CBL-EX-PWR-C13-SA

Switzerland

250 VAC, 10 A, 50 Hz

SEV 6534-2 Type 12G

CBL-EX-PWR-C13-SZ

Taiwan

125 VAC, 11 A and 15 A, 50 Hz

NEMA 5-15P Type N5-15P

CBL-EX-PWR-C13-TW

United Kingdom

250 VAC, 10 A, 50 Hz

BS 1363/A Type BS89/13

CBL-EX-PWR-C13-UK

Figure 6: AC Plug Types
AC Plug Types
Warning

The AC power cord for the switch is intended for use with the switch only and not for any other use.

Warning

Translation from Japanese: The attached power cable is only for this product. Do not use the cable for another product.

Note

In North America, AC power cords must not exceed 4.5 m (approximately 14.75 ft) in length, to comply with National Electrical Code (NEC) Sections 400-8 (NFPA 75, 5-2.2) and 210-52, and Canadian Electrical Code (CEC) Section 4-010(3). You can order AC power cords that are in compliance.

Caution

Ensure that power cords do not touch the switch components, block the air exhaust and access to switch components, or drape where people could trip on it.

Power Requirements for EX9251 Switch Components

Use the information in this topic to determine the power requirements for your switch.

Power Requirements for EX9251 Switch Components

Table 4 lists the power requirements for various hardware components when the switch is operating under typical and maximum voltage conditions.

Table 4: Power Requirements for Switch Components

Component

Power Requirement at 25°C (Watts; Typical)

Power Requirement at 55°C (Watts; Maximum)

Fully loaded switch

240 W

280 W

Table 5 lists the power requirements for a fully configured AC-powered switch operating under typical voltage conditions.

Table 5: Power Requirements for an AC-Powered Switch at Typical Temperature (25°C)

Chassis Configuration

Power Requirement at 25°C (Watts)

Power Requirement (Watts) with 90% Efficiency

Fully configured chassis running at high activity

240 W

266 W

Table 6 lists the power requirements for a fully configured AC-powered switch operating under maximum voltage conditions.

Table 6: Power Requirements for an AC-Powered Switch at Maximum Temperature (55°C)

Chassis Configuration

Power Requirement at 55°C (Watts)

Power Requirement (Watts) with 90% Efficiency

Fully configured chassis running at high activity

280 W

311 W

Calculating System Thermal Output

After you have calculated the power consumption for your configuration, you can use that information to determine the system thermal output (BTUs per hour). To do so, multiply the power consumption in watts by 3.41.

For example, in Table 5, we calculated the power consumption for a fully configured chassis running at high activity at 25°C typical temperature to be 240 W. Using that information, we can calculate the system thermal output for the configuration:

Power Supply Specifications for EX9251 Switches

Table 7 lists the AC power system electrical specifications.

Table 7: AC Power System Electrical Specifications

Item

Specifications

AC input voltage

Operating range: 100 through 240 VAC

AC input line frequency

50–60 Hz (nominal)

AC system current rating

  • 3.2 A @ 100 VAC

  • 1.37 A @ 240 VAC

AC system input power

312 W

Table 8 lists the AC power supply electrical specifications.

Table 8: AC Power Supply Electrical Specifications

Item

Specifications

Maximum output power

650 W

AC input voltage

Operating range:

  • 100 through 127 VAC

  • 200 through 240 VAC

AC input line frequency

50–60 Hz (nominal)

AC input current rating

  • 7.8 A @ 100 VAC

  • 3.8 A @ 240 VAC

Table 9 lists the DC power system electrical specifications.

Table 9: DC Power System Electrical Specifications

Item

Specifications

DC input voltage

Operating range: –44 through –72 VDC

DC system input current rating

20 A@ –44 VDC (maximum)

DC system input power

  • 331 W

  • 7.75 A @ –44 VDC

Table 10 lists the DC power supply electrical specifications.

Table 10: DC Power Supply Electrical Specifications

Item

Specifications

Maximum output power

650 W

DC input voltage

  • Minimum: –44 VDC

  • Nominal: –48 VDC, –60 VDC

  • Operating range: –44 to –72 VDC

DC input current rating

20 A @ –44 VDC