EX9208 Power System

AC Power Supply Description

The AC power supplies in EX9208 switches are hot-insertable and hot-removable field-replaceable units (FRUs).

You can install up to four AC power supplies in an EX9208 switch. Power supplies are installed in the rear of the chassis in slots PEM0 through PEM3 (left to right).

Each AC power supply weighs approximately 6.6 lb (2.99 kg) and consists of one AC appliance inlet, an AC input switch, a fan, and LEDs to monitor the status of the power supply. See Figure 1.

Figure 1: AC Power Supply for an EX9208 Switch

Each power supply has its own fan and is cooled by its own internal cooling system.

EX9208 switches support 2520 W AC power supply. The AC power supply supports both the low-voltage line (100–120 VAC) and the high-voltage line (200–240 VAC) AC power configurations.

Each AC power supply has a single AC appliance inlet located on the power supply that requires a dedicated AC power feed. We recommend that you use a customer site circuit breaker rated for 16.0 A @ 100 VAC or 16.0 A @ 200 VAC circuit breaker minimum for each AC power supply, or as required by local code. Doing so enables you to operate the switch in any configuration without upgrading the power infrastructure.

AC Power Supply Configurations

The EX9208 switch supports either the low-line (100–120 V) AC power configuration or the high-line (200–240 V) AC power configuration.

• In the low-line (100–120 V) AC power configuration, the EX9208 switch contains three or four AC power supplies, located horizontally at the rear of the chassis in slots PEM0 through PEM3 (left to right). Each AC power supply provides power to all components in the switch. When three power supplies are present, they share power almost equally within a fully populated system. Four AC power supplies provide full power redundancy. If one power supply fails or is removed, the remaining power supplies assume the entire electrical load without interruption. Three power supplies provide the maximum configuration with full power for as long as the switch is operational. The low-line configuration requires three power supplies and the fourth power supply provides redundancy.

• In the high-line (200–240 V) AC power configuration, the EX9208 switch contains two or four AC power supplies, located horizontally at the rear of the chassis in slots PEM0 through PEM3 (left to right). In a high-line AC power configuration, each AC power supply provides power to all components in the switch. When two or more power supplies are present, they share power almost equally within a fully populated system. Four AC power supplies provide full power redundancy. If one power supply fails or is removed, the remaining power supplies assume the entire electrical load without interruption. Two power supplies provide the maximum configuration with full power for as long as the switch is operational. In the two-PEM high-line configuration, slots PEM0 and PEM1 or PEM2 and PEM3 are used. The high-line configuration requires two power supplies, with the third and fourth providing redundancy.

DC Power Supply Description

The DC power supplies in EX9000 switches are hot-insertable and hot-removable field-replaceable units (FRUs).

You can install either two or four DC power supplies in an EX9208 switch. Power supplies are installed in the rear of the chassis in slots PEM0 through PEM3 (left to right).

Each DC power supply weighs approximately 6.2 lb (2.81 kg) and consists of one DC input (–48 VDC and return), one 70 A (–48 VDC) circuit breaker, a fan, and LEDs to monitor the status of the power supply. See Figure 3.

Each DC power supply has a single DC input (–48 VDC and return) that requires a dedicated circuit breaker. We recommend you provision 60 A or 75 A per feed, depending on the selected DIP switch setting. If you plan to operate a maximally configured DC-powered switch with DC power supplies, we recommend that you use a dedicated customer site circuit breaker rated for 70 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, we recommend that you provision a circuit breaker according to respective National Electrical Code and customer site internal standards to maintain proper level of protection for the current specified above or each DC power supply rated for at least 125% of the continuous current that the system draws at –48 VDC.

Figure 3: DC Power Supply for an EX9208 Switch

DC Power Supply Configurations

In the DC power configuration, the EX9208 switch contains either two or four DC power supplies located at the rear of the chassis in slots PEM0 through PEM3 (left to right). You can upgrade your DC power system from two to four power supplies.

Four power supplies provide full redundancy. If a DC power supply in a redundant configuration is removed or fails, its redundant power supply takes over without interruption. The DC power supply in PEM2 serves as redundant to the DC power supply in slot PEM0, and the DC power supply in PEM3 serves as redundant to the DC power supply in slot PEM1. If only two DC power supplies are installed, they must be installed in slots PEM0 and PEM1 or in slots PEM2 and PEM3.

Table 5 shows the components that are powered by each DC power supply slot. It applies to existing and high-capacity power supplies.