[amsat-bb] Re: EMCOMM, Generators, UPS etc was Phase 4 versus Eagle

Tue Dec 18 03:23:47 PST 2007

Hi Alan,

All good stuff. We go a bit further and are now using what are called 'line 
interactive' UPS models. These have essentially zero switch time. We've 
found that even with the typical short xx ms switch time of the usual type 
of UPS, some loads can't handle the glitch. The 'line interactive' versions 
are online 100%. Basically the incoming AC runs a battery charger. The 
batteries run an inverter that powers the load.

One other thing we do is use a bypass system around the UPS in case that 
fails. Pulluzzi makes a nice one, but quite expensive. We've had a scenario 
where a UPS came on line, ran for a while, but then failed 'in circuit'. By 
that time, AC power had returned, but there was no way to restore power 
because of the UPS failure. With the Pulluzzi switch, power can be routed 
around a failed unit automatically.

This equipment is used for mountaintop transmission systems, so not the 
typical Ham application, but the ideas apply to most emergency type 
situations.

73,
Mike, N1JEZ
"A closed mouth gathers no feet"

----- Original Message ----- 
From: "Alan" <ve4yz at mts.net>
To: <amsat-bb at amsat.org>
Sent: Tuesday, December 18, 2007 3:06 AM
Subject: [amsat-bb] Re: EMCOMM, Generators, UPS etc was Phase 4 versus Eagle

> Thanks to Ray, WB3ABN for an off-line heads up on how the UPS loads the
> generator.  Further surfing on the APC web site recommends sizing the
> generator to 3-5 times the load and/or reducing sensitivity of the UPS.
> Fortunately all my UPS models can be tweaked thru software to reduce
> sensitivity.  All that now has to be done is test a cold weather start of 
> my
> generator tomorrow and try the desensed UPS.  And if it works, we'll have 
> a
> ham situation where desense is a good thing.
>
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of Alan
> Sent: December 17, 2007 11:52 PM
> To: amsat-bb at amsat.org
> Subject: [amsat-bb] EMCOMM, Generators, UPS etc was Phase 4 versus Eagle
>
> Time for subject change folks.
>
> A question about "smoothing" A/C from a generator sufficiently to allow a
> UPS ( computer type such as an APC )to function.
>
> Does anyone have a DIY schematic for such as device?  I've "Googled" and
> found many commercial power conditioners but they are expensive.  Some 
> more
> costly than a top of the line generator in the <$1000 range.  Worse, if I
> were to replace my generator I have no guaranteed that the A/C output 
> would
> be of high enough quality to charge and run a UPS properly without carry a
> UPS into the store and asking them to fire up their brand new generator.
>
> It would be nice to stay on the air and have computers running when the
> generator is down for a fuel refill and oil check or when it otherwise
> hiccups and shuts down unexpectedly.
>
> Here's the problem.  All the UPS I have such as APC 750, APC 1050 and 
> others
> don't work when powered by a generator.  They "see" the A/C input as being
> sufficiently defective that they trip into battery backup mode immediately
> when they should be passing the A/C directly onto the protected devices 
> and
> be recharging the battery.
>
> At our last field day we had 4 gas generators on site of varying vintage 
> and
> make and price range. They ran our networked computers for contest 
> logging,
> radios, rotators, coffee pots, and fluorescent lighting in the tents. 
> We've
> done this for several years without a problem.  The A/C quality is good
> enough for the PC power supplies and radios or the external radio power
> supplies. During FD2007 I decided to add a UPS for each of 3 computers and
> then found that they all failed.  Testing after FD showed that the
> generators were the problem.  We don't use laptops, which, with their
> internal batteries have their own built-in UPS when you run them on the AC
> adapter.  We use old Pentium desktops because for the last 3 years in a 
> row
> we have had severe WX overnight, operating tents get blown down, computers
> and radios get soaked etc.  It's part of the fun of FD :-)
>
> The EMCOMM discussion reminded me that I should deal with this now and not
> wait for FD2008.  Also I should be prepared all year, not just for FD, to
> run my house, radios and computers in an emergency environment.  Recent 
> ice
> storms in the U.S. with a million folks without power for a day or two
> reminded me of the ice storm in Quebec several years ago when tens of
> thousands lost power for weeks.  Welcome to global warming and volatile 
> WX.
> As usual it is a case of "not IF; but WHEN".
>
>
> BTW,  I've shown my support for AMSAT, the executive et al by renewing my
> membership to a Life Time membership prior to all the QRM in the last 
> week.
> I would rather have made a separate donation but up here in the Great 
> White
> North we don't get a tax deduction for a U.S. not-for-profit :-(
>
> 73, Alan VE4YZ
> EN19
> AMSAT LM 2352
> http://www.mts.net/~ve4wsc/
> AMSAT A-485
>
>
>
>
>
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of Nate Duehr
> Sent: December 17, 2007 7:31 PM
> To: amsat-bb at amsat.org
> Subject: [amsat-bb] Re: Phase 4 versus Eagle
>
> MKM wrote:
>> Forget the EMCOMM support, that does not make sense anymore. Read on...
>>
>> WIMAX will be available from sprint soon. THAT will be a reliable
>> technology for ecom. With one access point, they will cover a wide
>> area for both data and voice. NOW, imagine multiple access point ( and
>> I mean 2 or 3 max) and regardless of what the ecom situation is, help
>> will get through.
>
> This service will be coming from U.S. carriers who wouldn't even put
> battery/generator backup on most of their wireless POP's until told to do 
> so
> by the FCC after Katrina:
>
> <http://www.datacenterknowledge.com/archives/2007/Dec/10/fcc_ruling_may_spur
> _generator_demand.html>
>
> Even with the new ruling, the FCC only recommends that such sites operate
> for 8 hours on emergency power.
>
> In other words, they don't expect the cellular companies to REFUEL those
> generators in any timely fashion.
>
> I worked for a large co-location company a few years ago, and we had a
> diesel contract that was VERY expensive.
>
> I talked to the truck driver once, and he told me that the order of his
> stops in bad weather/disaster situations would have been:
>
> Denver Health Medical Center - the alive ones at the hospital.
> Denver Police Headquarters and the Jail facility - the troublemakers, keep
> them inside.
> Denver Morgue - if it's warm out, you don't want the dead ones thawing and
> you probably have outdoor triage and refrigeration going on if things 
> aren't
> quite as bad as Katrina.
> Denver Library - Security.  Historical items.
> Our data center.
>
> Another route for another truck included the telco central office (Denver
> Main), and the "telco hotel" next door, as it's only customers that truck
> would serve.  As long as the outage lasted, those truck wouldn't leave 
> their
> "circular" routes which were planned to arrive just as generators were
> running out of fuel in a continuous loop.  Any delay and we (being at the
> bottom) would either fall off the list, or they'd make arrangements to 
> skip
> the library.
>
> That was his route with the diesel truck.  He would run around in circles
> and do it all again, if the problem lasted for multiple days.
> .
> Cell sites?  Nope.  WiMax sites?  No way.
>
> Reality bites:  Cell carriers don't pay to be on priority diesel 
> contracts.
> Diesel deliveries to cell sites are on "best effort"
> contracts.  They fall below everyone else with priority contracts.
>
> Good luck with your WiMax as an EmComm tool.  Let us know how well it 
> serves
> you when the power goes out and the diesel trucks can't get to all those 
> new
> generators at all the WiMax and cell sites
>
> Nate WY0X
>
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