The flywheels in the story transition the load from a failed main to a generator. The flywheel would carry the load while giving the generator up to 15 seconds to start and stabilize. This is a UPS that stores energy in a mechanical device rather than a chemical one.
Depending on the design of the unit, some switching may occur, but those times should be well within the tolerance levels of the protected equipment. Personally, I would think that the mechanical systems as described would be much safer than battery based systems. Each battery contains some really nasty chemicals and metals. At the end of the batteries' life, the disposal becomes an environmental issue. Larger batteries use 'flooded cell' technology which translates to concentrated liquid sulfuric acid. Even nastier than the 'gel' cells used in smaller systems where the acid is not in a liquid state. Both systems consume power. The flywheel has to be kept turning, but batteries have to be constantly 'trickle' charged. Our shop has failed twice due to battery issues. Once due to a bad battery in the UPS, and once due to generator starter batteries. Overall, IMHO, it looks like the TCO and environmental issues make this technology well worth a close look. My $0.02 -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of R.S. Sent: Wednesday, January 09, 2008 6:08 AM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: SEMI off topic Paul Gilmartin wrote: Back to the future. Flywheels were in use in 60's. Not in IT, but in industries, i.e. in yarn productions (synthetic fibres). long before UPSes. IMHO nowadays it is pointless. Modern diesel engines start in few (i.e. 4) seconds. Those engines are heated constantly (using electrical power). Flywheel is heavy, consumes energy, it wears, last but not least: it is dangerous. In the old days it was mounted in a bunker, rather underground. For computer equipment there is no difference between 4 seconds and 0.5-1 second. UPS is a must for switching time. -- Radoslaw Skorupka Lodz, Poland -- BRE Bank SA ul. Senatorska 18 00-950 Warszawa www.brebank.pl NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
