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<p>I agree as long as you have a long history with the battery/BMS. Since all of this is so new or constantly changing I would add a class T as it has a minor chance of being a failure item.</p>
<p>When I was testing this for Schneider, even they added the T fuse for insurance as no-one had tested the internal T fuse and contactor. Cheap insurance.</p>
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<pre><strong><span style="font-size: small;">Dave Angelini Offgrid Solar
"we go where powerlines don't"
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<p id="reply-intro">On 2025-07-14 10:12 pm, William Miller via RE-wrenches wrote:</p>
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<div dir="auto">When I design a lead-acid battery system I decide if I need over-current protection right at the battery or not. My logic is: if the leads are short, don't go through a wall and are well protected, I can rely on OCPD in the BOS cabinets. If any of these criteria is a no I put appropriately rated class T fuses right at the battery. </div>
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<div dir="auto">I'm thinking that since BMS devices have over-current protection baked-in, fusing at the battery would not be necessary for BMS equipped batteries in any case. Do you agree with that premise?<br clear="all" /><br clear="all" />
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<div class="v1gmail_signature" dir="ltr"><br />William Miller<br />Miller Solar.com<br />805-438-5600<br /><a href="http://www.millersolar.com" target="_blank" rel="noopener noreferrer">www.millersolar.com</a></div>
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