To complement:
1. Power is measured in Watts. Dot. No Amperes.
2. AC current power formula is a little bit more complex. It is P=U x I
x cos(fi). It is matter of "passive power" caused by coils and
capacitors. That's for linear receivers. To make long story short, most
IT equipment has cos fi very close to 1, so it is safe to assume just U
x I just like in DC realm.
3. Nominal values written on identification plates are tricky. This is
maximum value, good for fuse choice, but not for air condition, etc. The
difference can be quite big. Excercise: check your laptop power supply
and use wattmeter to check real power consumption. In case of lack of
wattmeter use ammeter and assume cos(fi)=1. Servers are different
animals, but the differences *are* still important. BTDT.
4. This is the topic for electrician, not for IT guy. (Ok, I'm licensed
electrician with little mainframe knowledge).
--
Radoslaw Skorupka
(looking for new job)
Lodz, Poland
W dniu 06.05.2021 o 06:54, Wayne Bickerdike pisze:
Jo Monk said:
Last I checked, PDUs are not sold by watts, but by volts/amps.
Sure they are. Doesn't magically turn into power. A/C power consumption is
not that easily derived, unlike DC. I'll continue to use the laws of
physics.
On Thu, May 6, 2021 at 1:41 AM Peter <[email protected]> wrote:
Thank you for the clarification. Now it help me to research further.
On Wed, 5 May, 2021, 7:29 pm Billy Ashton, <[email protected]> wrote:
You also might need to consider if you have redundant power supplies or
redundant/diverse power sources. There will not be a single definition
of power consumption based on the number of units or even the number of
devices. A 12U rack used as a patch panel will have no consumption, but
a 12u UPS rack will have much more.
------ Original Message ------
From: "Seymour J Metz" <[email protected]>
To: [email protected]
Sent: 5/5/2021 6:55:48 AM
Subject: Re: Datacentre Rack power clarification
That depends on the use profile. What equipment is in continuous use and
what is standby. Are you counting power for cooling?
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
________________________________________
From: IBM Mainframe Discussion List [[email protected]] on
behalf
of Peter [[email protected]]
Sent: Wednesday, May 5, 2021 2:25 AM
To: [email protected]
Subject: Datacentre Rack power clarification
Hello
Apology for posting a non mainframe questions here .
Is there a way to determine the total power consumption of rack with 12u
as
form factor ?
I am sure some of them would have used a benchmark to design a solution
for
any new server coming inside the data center floor.
So any clue or your experience would help me to analyse further.
Peter
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