MLS400

MLS400 Appliances have a redundant power supply unit (PSU) and support DC PSUs.

If necessary, you can replace a PSU. Note that all PSUs on an appliance must be of the same type (DC).

Warning: To protect yourself and the appliance PSUs from electrostatic discharge, make sure that you are electromagnetically grounded before you install, uninstall, or replace a PSU. We recommend that you use an ESD grounding wrist strap. Connect the grounding plug on the wrist strap to the appliance grounding point.

Warning - All work related to the DC power must be performed by trained and certified service personnel only.

Legend

Item	Description
1	Release lever
2	LED indicator for each power supply unit Off - No power cord is connected to any of the PSUs in the system Green - System on Blinking green - Power cords are connected to all PSUs, but system is off Amber - No power cord is connected to the PSU, but other PSUs in the system are connected to a power cord Blinking amber - Warning that a hardware issue (high temperature, high power, high current, slow fan) might lead to an issue with the PSU Blinking green amber - PSU undergoing Firmware update
3	Extractor handle
4	Two DC PSUs, next to each other
5	ESD grounding point
6	Alarm Off button for power supply units

Removing a DC Power Supply Unit

Before you remove a power supply unit, we recommend that you make sure that either:

• A second DC power supply is installed and connected to a working power source.

  Or

• The appliance is shut down.

To remove a DC power supply unit:

1. Remove the DC power cord from the DC PSU.

2. If the alarm sounds, press the Alarm Off button to the right of the DC PSUs.

3. While you press and hold the PSU release lever, pull the extraction handle to remove the DC PSU.

Legend

Item	Description
1	Release lever
2	Extractor handle

Note - Remove the power supply unit only with the extraction handle to prevent any possible damage.

Installing a Replacement DC Power Supply Unit

To install a replacement DC power supply unit:

1. Insert the DC PSU into the power supply slot.

2. Push the DC PSU until the release lever clicks.

3. Insert the DC power cord into the power supply socket.

   

4. Make sure that the power LED on the DC PSU is lit up.