topic Re: Power failure on PA-7000 in General Topics

Power failure on PA-7000

sbalcerzak — Tue, 30 Jan 2018 22:06:41 GMT

The PA-7000 Hardware Guide specifies they minimum number of active PS to provide enough power for a chassis depending on the type of power and number of NPCs installed.

For example, if the PA-7050 chassis is powered via 120V AC and has 6 NPCs installed it requires at least 3 PS functioning to provide full functionality. So, if the chassis is powered through two ciruits (2 PDUs), and one of them fails, it will be left with only 2 power supplies powered.

My question is what happens with the chassis if the minimum number of active PS is not met? Does it shut down completely, or shuts down only certain slots/NPCs. If it is partial, what is the rule on which slots become inactive/disabled?

I was trying to find an information about it in the documentation, but my search was unsuccessful.

Re: Power failure on PA-7000

reaper — Wed, 31 Jan 2018 10:12:02 GMT

If the chassis does not receive sufficient power it will shutdown completely

Re: Power failure on PA-7000

OtakarKlier — Wed, 31 Jan 2018 18:34:32 GMT

Hello,

Since most data center only supply and A and B side power. I would recommend staying with an even number of power supplys. That way two would always be up. Or you can get Y power cords so each power supply will receive both A side and B side power, i havent seen these in a long time however.

Just a thought.

Re: Power failure on PA-7000

sbalcerzak — Wed, 31 Jan 2018 19:57:36 GMT

Thanks for the response, @reaper

Do you have any pointer to the documentation where it is stated, or you're just basing it on your previous experience?

Re: Power failure on PA-7000

sbalcerzak — Wed, 31 Jan 2018 20:02:38 GMT

Hi @OtakarKlier,

Thanks for a suggestion.

However, it's not that I want to install or power uneven number of power supplies. It's just that for example PA-7050 has 4 of them, which makes that half of them will be powered from A circuit, the other from B. Now, if one circuit fails (for example PDU goes down), I will only have 2 PS getting power. Hardware guide stated though that if I have 5 or 6 NPCs installed, I need at least 3 PS to be functional. So my question was what happens in that scenario with the whole chassis - is the whole chassis going down, or it intelligently shuts down certain slots to save at least some functionality.