Re: UPS Problem and Recommendation -- MIDRANGE-L

Pete,

Well each has his own experiences eh? Not saying you gotta buy Trippe of course but I've not seen any of theirs fail and I currently have THREE APC's in my garage for recycling. One of them exhibited similar symptoms to what you describe but sadly I was not there for the fun.

Clearly I don't know how much stuff you have IN your BCH but a 1500VA UPS cannot handle 2x950 Watt Power Supplies (that's 1,900 Watts which (I don't recall exactly) assuming a power factor of 0.97 is 1.8 KVA or about 0.300 'too many'. If the thing isn't very full you might survive.

BCS Power supplies should be connected 'diagonally'. That is Upper left and Lower Right to one UPS and of course the remaining ones to the second. UPS. There is only one 'power domain' so all four supplies are feeding all components in the system.

If those UPS get a 1,900 Watt hit they will likely 'check out' rather quickly though I wouldn't expect a 'flicker' to take it down. Are the UPS in 'On-Line' mode or economy mode? On-Line provides much better protection especially for surges etc.

Lots of good power information here: http://www.wei.com/images/whitepapers/IBM-AGuidetoIBMBladeCenterPowerRequirements.pdf

- Larry "DrFranken" Bolhuis

On 4/25/2011 4:02 PM, Pete Helgren wrote:

Update: Flicker caused BCS to drop again. Tested one of the UPS's and
it tested OK. Tested the other and it blew during the test: Sparks,
flame, smoke and now the battery light is flashing weakly even though it
is unplugged and turned off. I guess I know which of the UPS's is "bad".

Still need to sort out which power supplies are the "redundant twins"
but I plan to order a new UPS (probably not a Tripplite though....) Any
recommendations? Looks like APC and Eaton are the big names out there....

Pete Helgren
Value Added Software, Inc
www.asaap.com
www.opensource4i.com

On 4/25/2011 8:33 AM, Pete Helgren wrote:

Looking for a little direction here:

Our JS12 runs in a BCS which has 4 950 watt power supplies. I
configured the power in the BCS so that there is redundancy on a
possible power supply failure. I also have two 1500 KVA UPS units
backing up the 4 power supplies (two redundantly on each UPS) . So,
theoretically, I'd have to have both UPS's fail or completely discharge
in a power outage in order for the BCS to lose power. Seems pretty fail
safe to me. Except, it isn't. The *slightest* flicker of electricity
and the BCS drops like a rock. So, I am trying to figure out what the
issue is. Both UPS's seem to be operating normally (I haven't run a
test yet because I don't want to lose the BCS during the day). The
LED's aren't showing battery failure or any issues. The UPS's are
Tripplite OMNIVS1500. I believe one of the two UPS's could be flaky but
I'll have to run a self test and that means they will switch over to
battery power during the test and if one of them is bad, I may lose the
BCS again and I don't want to do that during the day.

The thing that comes to mind is that perhaps the power supply redundancy
requires a particular configuration of UPS cabling that I have somehow
gotten wrong. I can't seem to find a diagram on how the redundancy is
configured on the BCS. Does the power supply in Bay 1 fail over to Bay
2 or does it fail over to Bay3? I am guessing 1 is redundant to 2 and 3
is redundant to 4 but I can't find anything that confirms it. If I have
a bad UPS and the power supply and it's redundant twin are BOTH plugged
into the same UPS, will that cause the BCS to go down? All of the
failure scenarios spelled out in the help text describe losing power to
*one* power supply. If a UPS fails and two power supplies lose power,
does the BCS go down as well. The BCS is configured with "AC Power
Source Redundancy with Blade Throttling Allowed"

Just trying to get to the bottom of the "flicker and die" phenomenon I
am experiencing. Any suggestions?