Cisco Power Supplies

AC and DC power supplies for Catalyst, Nexus, ISR, ASR and MDS platforms

About Power Supplies

Cisco power supplies are platform-specific. A supply is built for a particular chassis family, and the wattage on the label is only the first of several things that have to match.

Platforms in stock

Catalyst - including the 3560x and 3750x stackable switches and the 4500 and 6500 chassis
Nexus - including the 2200 fabric extenders
ISR - integrated services routers, including the 4000 series
ASR - aggregation services routers, including the 920 and 9000 series
MDS - storage networking directors such as the 9500

Wattages run from around 280W on small router supplies up to 3000W on large chassis.

AC and DC are not interchangeable

Many Cisco platforms were offered in both AC and DC variants, and the supplies are physically similar but electrically different. A DC supply expects a DC plant, typically in a carrier or central-office environment. Fitting the wrong type is not a configuration problem to be worked around.

Airflow direction matters in a hot aisle

Some Cisco supplies are built with a specific airflow direction, described as port-side intake or port-side exhaust. In a hot-aisle or cold-aisle containment design the direction has to match the rest of the chassis and the aisle layout. A supply that moves air the wrong way through a contained rack will recirculate hot air rather than reject it. Where a listing states an airflow direction, treat it as part of the specification rather than a detail.

PoE budget

On switches that supply Power over Ethernet, the power supply sets the PoE budget available to attached devices. If you are adding access points or phones and running short of power, the supply is often the limiting part rather than the switch.

Send us the exact chassis model and whether you need AC or DC and we will confirm the supply, including airflow direction where the platform offers a choice.

Featured Power Supplies Products

Browse all 22,013 Power Supplies SKUs.

Frequently Asked Questions

Can I use a higher-wattage Cisco power supply than the original?

Only if it is a supply built for that chassis family. Cisco supplies are platform-specific, and a higher-wattage unit from a different family will not fit or will not be recognised. Within a family, a higher-wattage supply is often used deliberately to raise the PoE budget.

What does port-side intake mean?

It describes the direction the supply moves air through the chassis. In hot-aisle or cold-aisle containment the direction must match the rest of the equipment and the aisle layout, otherwise the unit recirculates hot air instead of rejecting it. Where a listing states an airflow direction, treat it as part of the specification.

Are AC and DC versions interchangeable?

No. Many platforms were offered in both, and the supplies can look similar, but they are electrically different. A DC supply expects a DC power plant, typically in a carrier or central-office environment. Order the type that matches your installation.

Does the power supply limit how many PoE devices I can run?

Yes. On PoE switches the supply sets the power budget shared across ports. If you are adding access points or IP phones and running out of power, the supply is often the constraint rather than the switch itself. Tell us the switch model and how many devices you need to power.