This post is about starting a discussion on what you are using for fuses or DC breakers and what your thoughts are on watt loss. Victron recommends the Lynx Distributor for inverters using Mega fuses. Victron also recommends the Lynx Class-T Power In for connecting Lithium batterys. (because a hig…

Damn it, I ordered EF3 yesterday.

I’ll test them with a micro-ohm meter next time I’m in the shop and compare their resistance to comparable MEGA, MIDI, MRBF, CNN, ANN, and Class T fuses of similar amperages, depending on what we have in stock. I have four 250A EF3 fuses that were carried back from German for me. I’ll post my result…

Makes sense, when you look at a class t power in it has a massive amount of vent slots for cooling versus a relatively sealed regular power in or distributor. Potentially could mount some cooling fans on the front cover of the distributor (like this ai generated image but with holes cut in cover fo…

I have measured the Voltage drop of a Victron 125Amps ceramic megafuse in a Victron fuseholder with an accurate dc meter @87 amps current: 91.40 milivolt, 8 Watt powerloss. Total loss at the battery is 180milivolt, nearly 16 Watts; fuse + dc breaker + bms and terminals, voltage loss between each ce…

Found the power dissipation numbers for the ef3’s courtesy of the link from Ed: [Screenshot_20251225_122759_Chrome]

I took some time to measure common fuses we sell and use in our shop. The measurements are below, along with some notes. It appears we are out of stock on the ceramic 200A 80V MEGA fuses by Victron. I only had one so I measured using the one and then four 225A fuses. My power loss calculations for t…

Seems like a solid replacement for an 80V ceramic megafuse on a distributor or power in. Biggest issue in the US prob be availability of spares.

Victron ceramic megafuse in a Victron fuse holder. Connected with copper bar to terminal. [20251226_194043]

The problem of the Adler EF3 fuses is not only the higher resistance, but it barely fits in the Victron Lynx Distributor. And because of that. The lack of enough ventilation. I mean. We are talking about something like your fingernail between the plastic cover and the fuse. So guess what. Somehow it…

Fuses and Wattloss on T Class MEGA EF3 and DC Breakers

Q&A and troubleshooting

Vladyslav_Kh (Vladyslav) 25 December 2025 20:48 27

I guess they use the 315Vdc model; the 800Vdc is too big for the Lynx Distributor.

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Fuses and Wattloss on T Class MEGA EF3 and DC Breakers

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