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PriUPS Bonus: Multiple Supply Examples - The LARGE

  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

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.

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.

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.
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.
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.
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.



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!

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. 
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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Updated 17 May 2006