Server - Dual hot swap/redundant PSU - UPS question...

[Koldov]

Hi All,

 

So..... As I have dual PSU's

 

Just wondering if I could attach one of these to one UPS and the other to a different UPS?

 

Not really sure what I'm trying to achieve, but would the power switch over to the other PSU (on the other UPS) if the original one failed or ran out of juice in a power cut?

 

And in general, how do these dual power supplies work? Do they both run 24/7 or does one sit idle waiting for the other to fail?

 

Kol.

[fairm010]

My understanding is, on our DL380p's at least, is that they are both live and powering the thing so if one fails there is no power loss.

 

I have each PSU connected to a different UPS and there has been no problem.

[localzuk]

That's how we have it set up - one to each UPS.

 

- - - Updated - - -

 

That's how we have it set up - one to each UPS.

[Oaktech]

Likewise... one on each!

[Boredguy]

We have all our servers connected to 2 UPS's which is quite handy when I need to power one of them down to replace the batteries.

 

Both PSU's are always running to provide the load, but if you disconnect one of them the server just draws the extra from the remaining unit until you either plug it back in or replace the unit.

[Sagima]

again, like the above, our dual psu's are in different ups's

[dhicks]

Just wondering if I could attach one of these to one UPS and the other to a different UPS?

 

Yes - it means that you can take one UPS down for servicing, if needed, and that both power supplies are (hopefully) protected from power surges, lightning strikes and so on. If you have one power supply plugged in to the UPS and one into the mains you're covered for a power cut but might still get damage if there's a sudden surge.

[Oaktech]

Just to add to this, we went one step further and had all grey iec-iec cables in one UPS and all black in the other so you could see what was plugged to where....

[36Degrees]

Yep, same here. 2 UPSs and cable from each to the server.

 

Never had the facility here but at one company I worked for we had 2 separate feeds into the server room from the main "feed room", each with its own dado trunking.* Separate UPS connected to each which then went into separate PSUs!

 

* Room had been gutted and completely new electrics, etc. installed. Being a construction company helped as well!

[john]

The other way to do it if you only have 1x UPS is put one to the UPS and the other to the mains (on a clean fed supply obviously), so if your UPS dies (glares at most APC toys) you keep going and can swap the UPS out without the world ending and visa versa.

[PotNoodleTech]

Yes, one PSU onto each UPS here. As john says, if you've only got one make sure you keep one server PSU plugged into the mains as if your UPS dies (they can) you don't want that to take out the entire network!!