X-MimeOLE: Produced By Microsoft Exchange V6.5
Received: by onstor-exch02.onstor.net 
	id <01C8548D.6F307997@onstor-exch02.onstor.net>; Fri, 11 Jan 2008 13:06:21 -0700
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Content-class: urn:content-classes:message
Subject: RE: Power Reqs for the Pantera 2000
Date: Fri, 11 Jan 2008 13:06:20 -0700
Message-ID: <BB375AF679D4A34E9CA8DFA650E2B04E079AC3F3@onstor-exch02.onstor.net>
In-Reply-To: <BB375AF679D4A34E9CA8DFA650E2B04E06AE527F@onstor-exch02.onstor.net>
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Thread-Topic: Power Reqs for the Pantera 2000
Thread-Index: AchS7D/TLfMx+82gQFy2T7LcWnGXDwADC9XNAGGnwHAAAuK8BgAAmlvA
References: <BB375AF679D4A34E9CA8DFA650E2B04E06AE527F@onstor-exch02.onstor.net>
From: "Joshua Goldenhar" <IMCEAEX-_O=ONSTOR_OU=FIRST+20ADMINISTRATIVE+20GROUP_CN=RECIPIENTS_CN=JOSHUA+2EGOLDENHAR@onstor.com>
To: "Tim O'Callaghan" <tim.ocallaghan@onstor.com>,
	"Ben Piela" <ben.piela@onstor.com>,
	"dl-cstech" <dl-cstech@onstor.com>

I understand best practice.
We have not measured actual/peak draw.

The problem is that LSI got lazy and just put 515 watts on the spec
sheet which is what the PS is rated for.
On the Pantera 5000, the PS's are rated 600+ watts but LSI's spec sheet
lists 446 watts.

The 325 Watt number is from LSI. Peak may be a bit more.

-Josh

Josh Goldenhar
Phone: 408 963 2408, Cell: 408 547 7693

-----Original Message-----
From: Tim O'Callaghan=20
Sent: Friday, January 11, 2008 11:46 AM
To: Joshua Goldenhar; Ben Piela; dl-cstech
Subject: Re: Power Reqs for the Pantera 2000

Josh,

Is this the power rating at startup as all the disks are started?=20

Best practise is to rate the cabinet supply with the max current
required  to bring up all the trays simultaneously - i.e after a
unplanned power outage on the cabinet. Is the 325W value representative
of this?

Regards

Tim


Tim.OCallaghan@onstor.com

M:+44 7767435472
--------------------------
Sent using BlackBerry


-----Original Message-----
From: Joshua Goldenhar
To: Tim O'Callaghan; Ben Piela; dl-cstech
Sent: Fri Jan 11 10:24:57 2008
Subject: RE: Power Reqs for the Pantera 2000

The LSI spec sheets are max theoretical peak - the units really only use
325 watts per shelf (not 515) - the PS's are rated at 515 peak. Our new
Pantera 200 spec sheets specify 325 watts.

=20

-Josh=20

Josh Goldenhar=20
Phone: 408 963 2408, Cell: 408 547 7693=20

________________________________

From: Tim O'Callaghan=20
Sent: Wednesday, January 09, 2008 11:47 AM
To: Ben Piela; dl-cstech
Subject: RE: Power Reqs for the Pantera 2000

=20

Ben,

=20

You are correct, Power is calculated as volts x amps but AC voltage is
usually given as a peak to peak value,=20

=20

so to calculate the average voltage required for the power calculation
you multiply by 0.707

=20

240VAC x 0.707 =3D approx 170V
110VAC x 0.707 =3D approx 78V

=20

so to generate 1KW with nominal 240VAC supply requires 5.9A

=20

If the power rating is 515W for the unit - at 240VAC you will need just
over 3A

=20

Stepping the voltage down via the internal transformers allows the DC
rails to provide the higher current values given.

=20

I hope this helps

=20

Regards

=20

Tim

=20

=20

________________________________

From: Ben Piela
Sent: Wed 09/01/2008 18:20
To: dl-cstech
Subject: Power Reqs for the Pantera 2000

Hello all,

=20

I am trying to assist a customer with spec'ing out their rack space and
power requirements for a Pantera 2000 using the LSI 1932 disk shelves. =20

=20

In looking at the 1932 spec sheet off of the LSI web site, it says its
power consumption is the following: 515 Watts (+ 5V @ 19A/+12 V @ 35A).
Now, I am just a simpleton and I really don't know what the heck that
means.  I know that Power=3D(Volts)(Amps).  I know that circuits in the =
US
operate at 110V and 220V in the UK.  So, does this mean that this disk
shelf pulls 4.6A of current in the US and 2.3A of current in the UK?  I
am assuming an empty rack with 2 x 20A circuits feeding it.

=20

Thanks for your help,

=20

Side note:  Our Pantera 5000 spec sheet states that the Bobcat uses 1.9A
at 115V or 160W.  Now, my cool formula above (P=3DVA) is unable to put
those numbers together and get the same results.  My simpleton mind
mulitplies 1.9 with 115 and gets 218.5W.  Are there other multipliers in
there that I am missing in order to arrive at 160W?  The same doc shows
for the LSI storage that the Controller Module uses 446W and the Drive
module uses 428W.  Can I use my simple formula to find out the current
draw or is there more numbers involved to arrive at the correct answer?

=20

Thanks again,

=20

Ben

=20

