crewzer wrote: »
OK… I think I see what’s going on here. In short, a 250 A ANL fuse with the right AIC spec should work for you.
The 250 A fuse rating looks OK to me. Assuming full power (1750 W), minimum battery operating voltage (10.0 V), and the low end of Xantrex’ efficiency range spec (85%), the inverter will draw 1750 W / (10 V x 85%) = 206 A from the battery bank. Applying the typical 80% derating factor (or 125% multiplier), the fuse should be rated at 206 A / 80% = 258 A. A fuse rated at 250 A is probably “close enough”.
I suspect that Xantrex’ discussion about CCA specs and fuse AIC is derived from ABYC standards. The basic issue is that the fuse (or circuit breaker) must not only be able to open at its nominal rating, but it must do under extreme current conditions and open wide enough (fuse) or nor suffer internal damage (fuse block or inside of DC breaker) so that the device remains “open”. Blue Seas and Home Power magazine have further discussions on this issue.
So, what’s your proposed battery bank’s CCA? I agree that such specs for golf cart batteries appear to be impossible to find. But, we might be able to develop a reasonable cross-reference.
Specifically, the Trojan SCS200 deep cycle battery is rated for 12 V x 115 Ah. Its CCA spec is 620. A pair of these batteries wired in parallel would be rated at 12 V x 230 Ah, with a combined CCA spec of 1240.
A series-pair of Trojan T-105’s are rated for 12 V x 225 Ah – pretty close to the parallel-pair of SCS 200’s described above. So, let’s assume the series-pair of T-105’s would also have a CCA spec of ~1240. Continuing on with this model, a series-parallel combination of four T-105’s (12 V x 450 Ah) might have a CCA spec of ~2480.
The ABYC table in Xantrex’ manual indicates that a fuse (and fuse block) rated at 5000 AIC is required for a battery bank of this specification. Blue Seas’ ANL fuses and fuse block are rated at 6000 AIC, so they should do the trick for you.
Finally, Nigel’s recommendation to use heavy cable is well founded. The manual recommends 1 AWG cable for runs up to five feet, which is pretty short. 2/0 would probably be a better choice, and the Blue Seas fuse block can handle cable and lugs of that size.
Jim / crewzer
wildbill wrote: »
opinions on comparing anl type fuses to class t type fuses for a 3000w inverter with peak @ 5000w