[C320-list] Generator Blowing Inverter Fuses

[Bruce Hunter]

Warren & Jeff:                         Thanks for the replies. The charge/Inverter setup is a Xantax Freedom 20 with a Blue Sea SI ACR (automatic charging relay). The only time I've blown fuses is after a night at anchor when the selected battery was probably pretty low. No problems if running the generator with charged batteries. The generator is connected via the 30A shorepower plug used at the dock. I'm thinking maybe if before I run the generator after a night at anchor I could switch the battery selector switch to ALL, that might even the loads and not be such a shock to the circuit coming from the ACR. Speaking of the ACR I'm reading it's instructions and it calls for the fuses to be 75 to 90A for #6 wire, 100 to 125A for #4 wire and so on, I might step up the fuses from 50 to 60A since that's about as big as the stock holders will handle or even see what other fuse/ fuse holder opinions I could consider. I'll keep reading, and rereading on this, we are currently 100 miles from home so I'm not performing amt major changes until we get back, meanwhile I bought a bunch of Bussmann 50A fuses from Advance Auto right outside of Crisfield MD.
Bruce Hunter Nauti Time #719


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  On Mon, May 30, 2016 at 10:19 AM, Jeff Hare<Catalina at thehares.com> wrote:   Bruce,

Do you mean a Xantrex Freedom Inverter/Charger combo unit?    

So, one thing to look at is the max output charge current to the batteries on the Charger Side.  It's probably more than 50a total, but since there are typically 2 outputs, the normal max would be split between each output, or if one battery is quite low and the other is charged, you'll get higher charge current on the leg with the dead battery.

Here's the catch.  If you blow one of the fuses, the charger now sees that it only has one output and can now supply up to the max rated current to the remaining leg.  That could blow the second one, especially if you have the batteries in the ALL position.  I've experienced this first-hand when I had two discharged AGM batteries, one was more discharged than the other and all I had was 30a slow blow fuses and my 60a shore power charger.  One battery was fed more than 50% of the current and blew one of the 30 amp fuses, then proceeded to switch over and start charging the other battery and could take all the current it wanted and promptly blew the second fuse.  

The way around this is to buy fuses that are rated higher than the total charge output of the charger.  To get inline fuses with higher ratings and still have them fit the fuse holders, we use these:  http://amzn.com/B004AH8QLY   They are 60a fuses and fit the stock inline fuse holders.  You typically see these kinds of fuses used in high output car audio amplifier systems.  

I haven't found anything higher than 60a fuses for this kind of holder.  So, the trick here is make sure you use fuses that are rated at or above the total output of the charger.

-Jeff Hare
#809

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Bruce Hunter
Sent: Sunday, May 29, 2016 10:24 PM
To: C320-List at Catalina320.com; Warren Updike <wupdike at hotmail.com>; C320-List at Catalina320.com
Subject: [C320-list] Generator Blowing Inverter Fuses



We have a Xantrex inverter, when I hook up our Honda eu2000i generator it sometimes blows 1 or both of the 50 amp fuses that go to the battery(ies) anyone else have this issue? I'm thinking that maybe putting the battery selector switch on ALL might do the trick and have a bunch of fuses to try things out but I also thought asking about it here first would be an even better idea. Thanks in advance!Bruce Hunter Nauti Time #719