Hi John-
It's not a question of raw capacity. It is voltage regulation that is the
most important point here. The problem is that the generator has to be big
enough that it doesn't even know the load is there.
I tried this a few years ago when I knew there was going to be an outage due
to planned maintenance. The plant used about 3.6kW and got a 7.5kW
generator. When the generator got up to nominal voltage and the UPSs
transferred the load, the generator slowed down due to the load and the UPSs
kicked back in, releasing the load. That allowed the generator to speed up.
This created a really weird situation where everything was switching back
and forth every second or so. I let it run for a little while in the hopes
that the system would eventually get to an equilibrium point. It didn't.
The small gas-powered gensets use minimal flywheels and "quick" mechanical
servos to keep the weight down, but they are just too lightweight for decent
regulation. The momentum/inertia of the motor and generator, combined with
the mechanical servo, could not hope to keep pace with the instant load
switching capabilities of the UPSs.
I came away from that experience with a healthy respect for the REALLY heavy
flywheels that come with big diesel gensets. These dampen the genset's
response to sudden load switching.
-d
----- Original Message -----
From: "John T (Lists)" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, July 28, 2006 5:19 PM
Subject: RE: [IMail Forum] OT: Portable Generator for server room
Usage of this room is only 2.5 KW.
John T
eServices For You
"Seek, and ye shall find!"
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:Imail_Forum-
[EMAIL PROTECTED] On Behalf Of GlobalWeb.net Webmaster
Sent: Friday, July 28, 2006 2:10 PM
To: [email protected]
Subject: RE: [IMail Forum] OT: Portable Generator for server room
We rent a 50KW or 75KW generator from the local Equipment shop down the
street - we have approx 4 hours of battery life for our 5 racks of
servers;
this is plenty of time for them to drop one off to us - day or night.
We have gone with a 20KW before, but we place a big strain on a unit that
size.
Sincerely,
Randy Armbrecht
Global Web Solutions, Inc.
804-346-5300 x112
877-800-GLOBAL (4562) x112
http://globalweb.net
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of John T (Lists)
Sent: Friday, July 28, 2006 4:55 PM
To: [email protected]
Subject: [IMail Forum] OT: Portable Generator for server room
Has any one used a portable generator for a small server room to power the
server UPS batteries during an extended power outage?
If so, what brand and specs?
John T
eServices For You
"Seek, and ye shall find!"
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
