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PriUPS Bonus: Multiple Supply Examples - The LARGE
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System 3 (Large) |
Power Available |
2.7kW at 115VAC |
Power source |
Prius HV system - no power from 12V |
Converters used |
5ea Unipower 24V 50A |
Voltage supplied to UPS |
139 VDC - runs UPS and charges UPS batteries |
DC from Prius HV |
210-230VDC, 17Amps |
UPS model |
HP/COMPAQ R3000 XR (2U rackmount) |
Weight incl. UPS batteries |
80 lbs UPS, 50 lbs switchers = 130lbs |
Weight w/o UPS batteries |
80lbs |
Unlike the two smaller systems, the Compaq R3000XR has a 110V battery string.
Before I got the 48V supplies, I had planned on using this group of 5 24V
switchers, below.
Modular Arrangement
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To try this system out, I took five of the switching supplies and
prepared them for operation in the Prius. Here we revisit my
220VDC outlet strip, which now has an Anderson connector on the end that
mates with the connector permanently
mounted in the Prius. The outlet strip allows the 230V input up to
6 of these modular switchers to be connected in parallel to the Prius HV
supply. Although the switchers are designed to plug into a frame, I've
left them loose because depending on the UPS I'm using (see above table)
I'll want to have from one to five in the car. |
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I prepared each module by permanently wiring the sense connections
to their respective outputs, adding Anderson "Power Pole" connections to
DC plus and minus, and a short AC line cord to the 230V AC/DC input.
With this arrangement it takes only seconds to connect the modules in
series to get 24, 48, or more DC volts for the UPS. Important safety
tip: See all those bare wires at the Anderson connectors?
They need to be insulated and will be when I do a proper installation. |
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After quite a bit of consideration, I decided to use five of the 24V
supplies in series. I left the batteries in the UPS and set each
switcher to 27.7V to charge them. These supplies are rated at 50A
each, and with this voltage and current capability, it should be
possible to run two of the R3000XR supplies simultaneously. They
also come in 230V versions, and I have visions of running an Alpha amp
along with a full complement of 115V equipment from the trunk of the
Prius. |
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Here they are, mounted on an aluminum plate. My lack of
charisma with sheet metal can be verified by the uneven spacing of the
modules. At least now they'll stay together. |
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In the Prius trunk and powered up. Unlike the The "Large
System A," the five supplies in series provide enough voltage
to run the 3kW UPS and also to charge its batteries as explained above.
With these, the UPS requires no modification - they can pretend to be an
external battery with unlimited life. |
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I made a couple of "T" connectors with Anderson PowerPoles.
With these cables I can interrupt and "tap" the power supplies
anywhere in the series chain. That way I can power two UPS
units that require different input "battery" voltages. |
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Incidentally, although I think I have the right
crimping tool for the connectors, I always like to solder them
as well. I don't fully trust mechanical connections.
OF COURSE the T should be insulated! |
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Here I've tapped the 24V supply chain to also provide power for the
small UPS as well as the full voltage for
an XR3000. The small UPS is shown providing 127VAC, a little high
because there's no load on it. |
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Even with the five switchers, the XR3000, and the 115VAC UPS the
trunk is relatively empty. With a bit of ingenuity and wire
dressing it would be less of a heap. Note that one shouldn't
be driving the car with this mess in the back! For ham radio "Field
Day" I'm going to run a 230V version of the XR3000 to power a KW amp,
and an XR1500 for the transceiver, computer, etc. At least I will
if I don't get a better offer. |
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