DC Power Input and PoE Power Extension on XMG2230 Series Switches

XMG2230 Series switches support a dual power architecture consisting of an internal AC power supply and an optional external DC power input. While the internal AC power supply is sufficient for standard operation, the DC power input enables specific deployment scenarios such as higher PoE power budgets and DC-based infrastructure designs. 

This article explains how the DC power input works in practice, with a particular focus on PoE power extension behavior, power source priority, and important deployment considerations.

Important Notice: Please pay attention to the following important points:

• The external DC power supply is not provided by Zyxel

• Zyxel does not validate, certify, or recommend any specific external DC power supply model.

• Only qualified electricians or trained technical personnel are allowed to select, install, and connect an external DC power supply.

• The customer is fully responsible for choosing a DC power supply with the correct voltage, power capacity, and electrical characteristics.

• Zyxel is not responsible for any damage, malfunction, or safety issue caused by an incorrect or incompatible DC power supply.

• The DC power input is designed for deployment and power design purposes only and must not be used as a repair solution for a failed internal power supply.

Power Architecture Overview

XMG2230 Series switches support two power sources:

• Internal AC power supply

• External DC power input

  • Supported input voltage: 50–57 V DC

  • Maximum input current supported by the switch:

    • XMG2230-28HP: up to 31 A

    • XMG2230-52HP: up to 51 A

The current values shown above indicate the maximum DC input current the switch may draw under full load. They are not fixed current requirements for the external DC power supply.

The system applies a power priority mechanism:

• AC power has higher priority than DC power

• When both AC and DC are connected, the switch operates in AC power mode

• DC power is primarily intended as:

  • a backup power source, or

  • a DC-only operating mode for extended PoE power

More about DC Power Connection in the user guide 

• XMG2230-28HP

• XMG2230-52HP

AC Power Mode (Default)

When the switch is powered by the internal AC power supply:

• PoE budget is limited to the AC PSU capability

• Example:

  • XMG2230-28HP: up to 700 W

  • XMG2230-52HP: up to 960 W

In this mode, PoE power is capped regardless of whether a DC power supply is connected.

DC Power Mode (Extended PoE)

When the switch is powered only by DC power:

• A significantly higher PoE budget becomes available

• Example:

  • XMG2230-28HP: configurable up to 1440 W

  • XMG2230-52HP: configurable up to 2400 W

This behavior is explicitly reflected in the switch GUI:

PORT > PoE Setup > Total Power (W)

By default, this field displays the total power the Switch can provide to the connected PoE-enabled
devices on the PoE ports.

• XMG2230-28HP: 700 W (default). Enter a number ranging from 1 to 1440 W to set the maximum
  PoE power the PD(s) could use from this Switch.
• XMG2230-52HP: 960 W (default). Enter a number ranging from 1 to 2400 W to set the
  maximum PoE power the PD(s) could use from this Switch.

Note: The “Total Power” field is available for configuration only when the switch is powered up by DC.

Important Power Priority Behavior

• If the switch is powered by DC only, the extended PoE budget is available

• If AC power is connected at any time, the system:

  • automatically switches to AC power

  • reduces the PoE budget to the AC limit

Example scenario:

• DC connected first → PoE budget up to 2400 W

• AC connected afterward → system switches to AC → PoE budget drops to 960 W

Therefore:

• To use PoE power above the AC limit, the switch must operate in DC-only mode

• AC power must not be connected in this scenario

External DC Power Supply Considerations

Zyxel does not supply an external DC power unit for the XMG2230 Series.

Based on internal technical guidance:

• Zyxel does not validate external DC power supplies

• The DC input is universal, allowing different vendors and models

• A high-power external DC supply is required to reach maximum PoE budgets

• An example external power supply capable of delivering up to 2400 W has been identified internally

• For best efficiency, tuning the DC output voltage close to 55 V DC is recommended, within the supported range

Safety and Deployment Requirements

Using the DC power input—especially in high-power PoE scenarios—introduces additional responsibilities:

• Correct power supply sizing (voltage, current, total power)

• Proper cabling, grounding, and protection

• Thermal and electrical safety considerations

• Compliance with local regulations

Because of these factors:

Selection, installation, and operation of an external DC power supply must be performed by qualified personnel with appropriate electrical expertise. Improper selection or installation may result in reduced performance, equipment damage, or unsafe operating conditions.

Example of External DC Power Supply and SVR Adjustment

An external DC power supply may be used with XMG2230 Series switches only if it meets the required electrical specifications.

As an example only, the MEAN WELL UHP-2500-48 power supply matches the required electrical characteristics:

• adjustable output voltage within 50–57 V DC, and

• sufficient total power capacity to support extended PoE operation.

The MEAN WELL UHP-2500-48 includes a manual voltage adjustment feature called SVR (voltage adjustment potentiometer).
By default, this power supply outputs approximately 48 V DC and must be manually adjusted using SVR to a supported voltage level (for example, around 55 V DC) before connection to the switch.

If SVR is not adjusted correctly, the DC input of the switch may not operate as expected.

Important Notes:

• The MEAN WELL UHP-2500-48 is provided for example purposes only, based on electrical compatibility.

• Zyxel does not validate, certify, or recommend any external DC power supply model.

• Other DC power supplies may require different voltage adjustments or configuration steps.

• Incorrect voltage or power settings may cause malfunction or damage.

Selection, configuration, and installation of any external DC power supply must be performed by qualified electrical specialists only.