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Cisco Meraki

Combined Power on MS Devices

Overview 

Combined Power allows switches with two power supply modules to draw power from both the modules simultaneously.

 

Traditionally, switches with two power supply modules are designed to use them in redundant mode. In such a configuration, only one of the modules provides power to the switch at any time, while the second module remains on stand-by, ready to sustain the supply of power if the first module was to fail. 

 

With Combined Power, the second power supply module, will also provide power for PoE up to its maximum rated limit, while still acting as a stand-by power supply for the switch control system.  In the event of a failure on the primary power supply module, the secondary module will ensure power to the switch remains uninterrupted while the power provisioning for PoE will be modified as criteria explained in the section Power Budgeting with Combined Power.

 

Combined Power Supported Models: MS350, MS355 and MS390 Series.

Configuring Combined Power

To configure the power mode, navigate to Switch > Configure > Switch Settings. Here you can choose between Redundant power and Combined power, as the 'default power supply setting.' for the switches in your network. If there are switches in your network which should not follow the default power settings, you can map those switches to either of the power modes using custom lists, from the 'power supply settings exceptions,' section.

combined power.png

 

This option is only available when the switch has two power supply modules inserted and powered. This feature is available only for Switches running firmware MS 11-0 and above.

Power Budgeting with Combined Power

 

Switch Model

Combined Power Budget Switch Model Combined Power Budget

MS350-24P

720W MS355-24X 1440W
MS350-48LP 740W MS355-24X2 1440W
MS350-48FP 1440W MS355-48X 1480W
MS350-24X 1440W MS355-48X2

1480W

MS390-24P    720W MS390-24U 1440W    
MS390-24UX 1440W MS390-48P 1152W
MS390-48U 1800W     MS390-48UX 1590W    
MS390-48UX2-HW     1745W    

Note: The switches will budget based on the PoE device classification, the budget is allowed to exceed available power as it's used to gauge overall power that might be consumed on the switch. Devices will continue to be powered until the consumption goes over the available amount of power or one of the power supply module fails. In this case the lowest port numbers take precedence and power will be pulled from the highest ports thus denying them power

 

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