Cisco Systems AS5800 manual DC-Input Power Specifications, AC-Input Power Specifications

		DC-Input Power Specifications
Table 1-9	Standard AC-Input Power Supply LEDs (continued)
LED	Color	Description
TEMP	Yellow	Lights when the power shelf has shut down because of
		overtemperature conditions.
I LIM	Yellow	Lights when the power shelf is overloaded and operating in a
		current-limiting state.

The current limit LED lights for either of the following reasons:

• The power supply is operating in a current overload condition, such that the voltage is drawn below the fault threshold level.

• The power shuts down due to an overcurrent condition in the power supply. (When this occurs, both the I LIM LED and the Fault LED light.)

DC-Input Power Specifications

The PEMs provide –48 VDC power, which is distributed from the filter module to the dial shelf backplane. The analog isolators in the filter module are provided with 15 VDC. No damage will come to the PEMs if any or all outputs have no load (no load occurs when there are no cards plugged into the backplane) or if the maximum input voltage is exceeded; however, input voltages that exceed 75V will eventually trip the PEM 60A circuit breaker, and you may have to reset the breaker.

The Cisco AS5800 supports several types of logic cards with varying power requirements. As a result, each logic card DC-to-DC converter system is isolated from the distributed –48 VDC power, creating a more stable distributed power system.

AC-Input Power Specifications

The Cisco AS5800 accepts AC-input power using a separate, self-contained AC-input power shelf, which converts AC-input power into DC output for use by the DC-powered dial shelf. The AC-input power shelf is rack mounted and has a safety cover that shields the electrical connections in the power shelf rear.

The AC-input to DC-output connection supplies –48 VDC-output power to the dial shelf PEMs. The PEMs receive the –48V and transmit power to the filter module. Power flows through the filter module to the backplane, where it is distributed to the dial shelf controller card and dial shelf cards.

The AC-input power shelf includes two 2,000W AC-input power supplies that plug into a common power backplane in the AC-input power shelf. A single AC-input power supply is capable of powering a fully configured Cisco 5814 dial shelf. The second power supply provides full redundancy.

During normal operation, the dual AC-input power supplies provide automatic loadsharing, with each power supply supporting 50 percent of the power load. When you remove one of the AC-input power supplies, the remaining power supply immediately ramps up to full power and maintains uninterrupted system power.

The AC-input power supplies are “hot-swappable,” allowing you to remove or replace a power supply while the system is operating; system operation is not affected. Whenever possible, we recommend that you connect each AC-input power supply to a separate AC power source.

Cisco AS5800 Product Overview 1-41