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<div class="moz-cite-prefix">Probably too late at this stage in the
design, but if you used hydraulic cylinders instead of electric
motors, you could have the brute power stored in hydraulic
accumulators. Then all you need to put on the UPS is the control
stuff, which would be COTS, instead of some mongo UPS you have to
create. Lot of amusement park rides use hydraulic accumulators
so they don't need huge pumps to satisfy momentary peak demands of
the ride, just a smaller pump that runs steadily all day long. <br>
<br>
Hmmm... One large UPS system I saw described in a magazine one
time had a motor/generator set with a big flywheel and a pneumatic
motor. The flywheel smooths out the energy and provides the
couple of seconds of carryover. The pneumatic motor is hooked
into a large bank of compressed air tanks, and the control system
opens up the air valve as needed. The compressed air kept the
data-center online long enough for the backup generator to start
up and settle out. A separate air compressor recharges the air
bank when the power comes back. No idea who makes it. <br>
<br>
Good luck with the job. <br>
<br>
--Dale<br>
<br>
On 1/15/2015 11:26 PM, Michael Sauder via Stagecraft wrote:<br>
</div>
<blockquote
cite="mid:CAKj1yom1P6DxEFH2hr-q=6bmWXBG=-DcVrWw0or+mvZxosJJhg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">On Thu, Jan 15, 2015 at 10:41 PM,
Jerry Durand via Stagecraft <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:stagecraft@theatrical.net" target="_blank">stagecraft@theatrical.net</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Just
a comment on the auto-taps. I'm sure your electricians
know about<br>
it, but just in case it's worth noting. When you get a
brownout and the<br>
transformer switches, your Amp draw will go UP by about
the same<br>
percentage as the brownout goes DOWN. Not a problem
unless you're<br>
running close to full capacity and you have a deep
brownout.<br>
</blockquote>
<div><br>
</div>
<div>Yep. I'm a dodgy electrician, but I still knew this
much, and told as much in my email to the producers
tonight.</div>
<div><br>
</div>
<i>"I'm sure your electricians know about it, but just in
case it's worth noting."</i></div>
<div class="gmail_quote"><i><br>
</i></div>
<div class="gmail_quote">I've learned not to assume a single
thing. My emails tend to be lengthy and detailed (which
sometimes means people don't read them carefully), but at
least then I can't be blamed for not throughly explaining
something.</div>
<div class="gmail_quote"><i><br>
</i></div>
<div class="gmail_quote">Despite this, the electrical drawings
I received earlier this week were full of errors, some
major. How much of this was incompetence, how much was lost
in international translation, and how much of it was my own
inexperience, I don't know...</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">A side point I'm really curious
about: When you read "220V 3 phase" do you folks read that
as "Each leg is 127V, any two of which give you 220V" or do
you read it as "Each leg is 220V, any two of which give you
380V"? (Convert to U.S. figures as needed)</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">As you might guess, we need one
interpretation (127V per leg) while the drawings specced
another (220V per leg). Which meant that a required 50kVA
transformer was not in the drawings, or budget.</div>
<div class="gmail_quote"><br>
</div>
<div class="gmail_quote">Michael S.</div>
</div>
</div>
<br>
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