Changing Battery/PV Breakers

Discussion about OutBacks "PS" enclosures

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m5guru
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Changing Battery/PV Breakers

Post by m5guru »

I purchased a two inverter PS2 system (2 x GVFX3648) with a MX60. The system came with incorrect breakers for the DC side. They are the 250A breakers. My understanding is that I should have 175A breakers. So I had the supplier send me a pair of 175A breakers, but now I have to swap them out.

Knowing a rudimentary amount about the way these systems work, I am looking for some guidance on how to do the swap in a safe, sane fashion.

Can someone step me through the things I need to make sure I do and what order I should do them in so that I don't destroy my system, burn down my house, or worse shock myself into la-la land.

I am assuming that I'd shut off all the PV inputs at my PSPV. And I'm assuming I'd shut off my AC input from my grid input (there is no generator or secondary AC input). And I'd disconnect my battery bank from the current breaker. (Do I have to disconnect the negative side as well?) Then I assume I just go in and unbolt the current breakers and bolt in the new ones? Then hook up batteries, PV, and AC input again?

Thanks,
David
Kent Osterberg
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Post by Kent Osterberg »

You are correct in assuming that all sources of power need to be discconected befor working in the PS2DC.

Disconnect the PV system at your PSPV combiner by switching the breakers off.

If the batteries are in a metal enclosure, remove the battery connections at the grounded end (in almost all systems that would be the negative terminal). If the batteries are in a wood or plastic enclosure, disconnecting at either end is sufficient. Be extra careful working with tools near the batteries! Connecting two battery terminals with a metal tool can be disasterous. It is best to put several layers of electrical tape on the handle of tools you'll use near the batteries.

If you have parallel battery cables (two positive and two negative) going from the batteries to the PS2DC, make sure that both battery cables get disconnected.
GarrettCoMd
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Post by GarrettCoMd »

I did basicly the same thing when I worked on my PDC, however I disconnected the positive lead from the battery bank. I am unsure of the metal enclosure statement in Kent's post.......the negative is usually to ground as well as the negative bus bar.

Kent, did I misunderstand your post??
Kent Osterberg
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Post by Kent Osterberg »

GarrettCoMd,

Most systems are negative grounded with the ground connection in the PS2DC. When you have a metal battery enclosure, such as a PSR, it is a lot safer to disconnect the grounded (negative) battery terminal rather than the ungrounded (positive) terminal. Just as in a car, if the tool touches the metal enclosure and an ungrounded battery terminal, the battery is shorted with possibly disasterous consequences. There is no such problem at the grounded terminal, so it is safer to disconnect there.

For plastic or wood battery boxes, the battery may be disconnected anywhere.
GarrettCoMd
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Post by GarrettCoMd »

Thanks for the info, I guess I was under the wrong impression.

Jerry O. :oops:
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