Using the PSPV as a dc control panel

Discussion about the Power System PV Combiner (PSPV)

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roadie
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Using the PSPV as a dc control panel

Post by roadie » Sat Aug 20, 2005 8:21 am

I'm looking for a panel to serve as a disconnect for my solar panels and my MX 60. The panels that I'm using are 4 Kyocera, KC-120s wired to put out 7.1 amps at 48 volts and one large panel putting out about 7 amps at 48 volts . I know that there are breakers that will handle the panels. But my problem is coming out of the MX 60, the amp output will be close to 70 amps. My battery array is a 12 volt array. The voltage on the battery array is not changeable. This installation is in a motorhome with a factory installed 12 volt inverter. The batteries are 4 8Ds. I have not taking delivery of the motorhome, so I don't how much space I will have to mount every thing. But I know space will be limited. I know I can get a t-type fuse that will handle the amps, but I would prefer to use a breaker.

Thanks Roadie

Scott Payne

Post by Scott Payne » Mon Aug 22, 2005 12:36 pm

roadie,

I'm not sure what your question is? Are you asking if you can connect more PV panels to the MX-60 that would potentially produce >60amps of battery charging?

If this correct, then yes you can, but the MX-60 will limit it's charge current to safe levels, possibly wasting some of your solar production.

You should also be aware that mixing the 4 Kyocera panels in series with one 48V panel may reduce your PV production due to mismatched maximum power points and differing open circuit voltages.


Scott

roadie
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using the pspv panel as a dc control panel

Post by roadie » Tue Aug 23, 2005 1:49 pm

My questions are as follows: 1. Is there room to install a second isolated dc bus to use as a output bus for a MX60 with the first bus having 2 or 3 small ( less than 10 amps) on the first bus? 2. Can I get a dc breaker with a disconnect capacity of 70 amps to mount on the second isolated bus and use the 70 amp breaker to disconnect the MX60 from my batteries? Roadie

Kent Osterberg
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Post by Kent Osterberg » Tue Aug 23, 2005 8:48 pm

roadie,

Technically, the PSPV doesn't qualify as a disconnect because the breakers are not accessible without a tool. It would still serve in the manner you are proposing except for the fact that the largest breaker available for it is 30 amps.

Also, the system that you are proposing is larger than the maximum recommended size for a single MX-60 with 12-volt output. There is no harm in doing this but there may be times that the MX-60 is delivering all the power that it can but not all the power that is available from the PV array.

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