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oskaratk
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Dual PSU priority

Tue May 30, 2023 6:09 am

Howdy,

do devices with dual PSU, like the CCR2004, have a priortity of which PSU is used ?

My case is one PSU connected to grid, the other one to an inverter (battery) . I certainly want to use grid power when avilable

Thanks
Oskar
 
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mkx
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Re: Dual PSU priority

Tue May 30, 2023 7:07 am

No, there is no priority. The reason is that power "bus" on low-voltage side in MT devices is a very simple one and doesn't allow any preference.

There's a slight difference on devices which have DC inputs, on those power input with highest voltage is used. If power supply voltages (under load) are equal, then power will be drawn from both supplies.
I guess it's the same in your device, but you don't have control over internal workings of power supply.
 
oskaratk
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Re: Dual PSU priority

Tue May 30, 2023 4:31 pm

Thanks,
not quite what I wanted to hear, but at least it's clear
 
pe1chl
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Re: Dual PSU priority

Tue May 30, 2023 4:38 pm

Maybe you have other equipment and you can use an "automatic transfer switch" to switch between inverter and mains, and feed its output to the CCR2004 and maybe also to equipment that has only one powersupply.
Usually you can set a priority in such devices (or it is fixed and you can wire it according to your preferences).
We also use that behind our UPS to handle failure of the UPS while power is still available.
 
pe1chl
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Re: Dual PSU priority

Tue May 30, 2023 4:39 pm

Maybe you have other equipment and you can use an "automatic transfer switch" to switch between inverter and mains, and feed its output to the CCR2004 and maybe also to equipment that has only one powersupply.
Usually you can set a priority in such devices (or it is fixed and you can wire it according to your preferences).
We also use that behind our UPS to handle failure of the UPS while power is still available.

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