Re: Maintenance on UPS

[DrFranken <midrange@xxxxxxxxxxxx>]

Yes but nobody was there to flip the switch. When they got there 
everything was down so they had 'sparky' remove the thing and wire in 
two smaller units until the new UPSs arrived.

- L

On 6/14/2011 10:01 AM, Chuck Lewis wrote:
> So they didn't have a bypass switch? As long as we are talking about
> UPS's no one should had one and not have a bypass switch.
>
> JMHO,
>
> Chuck
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of DrFranken
> Sent: Monday, June 13, 2011 10:29 AM
> To: Midrange Systems Technical Discussion
> Subject: Re: Maintenance on UPS
>
> Additional Comment re: Replacement of Batteries.
>
> Batteries work as a team. Depending on your UPS there are a number of
> them in series (meaning they all carry identical current but may not
> have exact voltages) and sets (or strings) of these are often connected
> in parallel. These then have identical voltages (as a set) but may or
> may not carry the same current.  Why do you care? Because if you only
> replace SOME batteries, the newer ones, being fresh, will provide more
> current and hold a higher voltage. The old ones will not hold voltage as
>
> well and may require additional charging compared to the new ones.  But
> they are all connected together (in most UPSs) so they ALL get charged,
> need it or not. This has two detrimental affects:   1) Wasted
> electricity and additional heat, and 2) The new batteries get abused and
>
> their life shortened. This can cause battery swelling and resultant
> problems replacing them.  In extreme cases UPS failure can result. Just
> recycled a big APC unit last week that died from this very abuse.
> Batteries in the unit were dated all over the last four years. Some had
> swelled to 20% larger than their original size ruining the battery cases
>
> as well. Worse than all that, the UPS dumped power completely to the
> data center it was feeding causing a full day outage.
>
> Replace your UPS batteries as a full set.
>
> Reminds me of the old man and his oil filter "You can pay me now, or pay
>
> me later."
>
>       - Larry "DrFranken" Bolhuis