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What voltage is 48 volts?

Posted: Mon Jul 29, 2019 7:01 pm
by mhoppes
When set to 48VH, what actual voltage is coming out of the pins on the switch?

Re: What voltage is 48 volts?

Posted: Mon Jul 29, 2019 8:30 pm
by lligetfa
It should be close to 50V. What does it say for Board 48V?
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Re: What voltage is 48 volts?

Posted: Mon Jul 29, 2019 8:35 pm
by mhoppes
49. So that’s the output voltage?

Re: What voltage is 48 volts?

Posted: Tue Jul 30, 2019 8:18 am
by sirhc
mhoppes wrote:49. So that’s the output voltage?


48V was used to identify 48V POE as so many people are familiar with that number but what comes out as 48V is the direct power supply supplied voltage to the "switch board" as it does not condition (step up or down) the input voltage provided to the switch board for 48V POE option like 24V which is stepped down (regulated) on the switch board.

Could you imagine how many people would ask questions if we called 48V whatever the actual voltage is as power supplies are +/- tolerance.

I can imagine it now "What is 50V or 51.2V POE option for, I need 48V?"

For instance if you look at UBNT AF POE adapter and our POE WS-6 POE adapter it is 54V but most people think 48V.

Most 48V POE devices accept a range up to 54V as they immediately step it down to lower voltages. We chose 50V+/- as the tuned voltage on our power supplies.

Also the higher the voltage the less amperage needed for long cable runs and it helps with voltage drop.