Generator blows house battery fuse

Bobbettyl · 05-22-2022, 01:08 PM

2020 Winnabago View 24d
This is 3rd time I have a blown house battery fuse located in battery compartment. It seems to happen when after a couple seconds of starting generator. Now twice before I had this fuse replaced and was able to start and run generator. So fuse blowing is erratic.

Today I go to coach where I store it, turn on house battery rocker switch and go to start generator and generator makes a momentary sound and then nothing.

Panel over frig then flashes b01 which now tells me it 8s nether fuse located in battery compartment.

So bottom line it works after replac8ng this fuse and then it blows that fuse man’s works for little while before blowing that fuse again!

Morich · 05-22-2022, 02:34 PM

Tough when things seem to happen for noreason but maybe some questions will point to a cure.
One first thing is to question some things about how the batteries are treated while stored. There is often confusion about the battery disconnect switch and that it only turns off PART of the electrical items.There are safgety items which ar eleft on ---even when the switch is turned off! These are things like the popane leak detector and CO monitor and some step functions. We don't get the good info on exactly what is left on in the newer RV, so we have to guess at some of that.

So the question may be if you have any form of charging for the coach batteries when it is stored? Review what happens and see if this might make any sense.

If there is no charging to keep the batteries up, so that they get low at times, but still enough to start the generator, but at other times they are a bit lower and not enough voltage to start the generator well and that blows the fuse.
A "funny " item on power is that we think of high voltage and current blowing fuses but it can also be caused by low voltage!

Without knowing what you do in far more detail, this has to be close to a guess but making sure the batteries don't run down when stored is a constant problem for many folks and it takes some thought about how to treat the RV, until we get used to each one we might have.

Bobbettyl · 05-22-2022, 03:15 PM

Two new deep cycle batteries maybe 2 weeks ago. When I store RV I turn off house and what they might call the salesman switch. Batteries were fully charged a couple of days ago when generator was still running.

So I don’t think battery condition figures in the equation hat this time.

Thanks for your reply.

eyecando · 05-25-2022, 08:06 PM

I believe the issue is caused by an undersized (125 Amp) fuse. I had the same issue. I replaced the fuse with a 175 amp fuse and haven't had another blown fuse so far. If it blows again, I'll increase the fuse rating.

Most starter circuits, for example those in your car are unfused due to the large current flow when starting the vehicle. That value could vary a lot depending on how hard the starter has to work.

I read in another forum that the factory has uprated the fuse, but I don't remember the recommended size.

Bobbettyl · 05-25-2022, 08:54 PM

Thank you and you are correct. Winnabago did upsize this fuse and didn’t make any general announcement. After blowing 3 fuses my repair shop called Winnabago and found this out. Funny it didn’t blow any fuses for first 2 years. Thanks again

Bobn1957 · 06-02-2022, 01:09 AM

I would suggest the starter is dragging the rotor which means one or both of the bearings are shot. The little starter on the genset shouldn't be drawing more than 125 amps!

eyecando · 06-02-2022, 06:14 AM

Quote:

Originally Posted by Bobn1957

I would suggest the starter is dragging the rotor which means one or both of the bearings are shot. The little starter on the genset shouldn't be drawing more than 125 amps!

i just placed a tong ammeter on the fused circuit and it recorded 167 amps max. The coach batteries were fully charged and the converter was on at the time. I'm sure if the coach batteries were low, the current would have been significantly higher. Of course, lower temperatures. the starter armature dragging or several other things could increase the starting current.

From what I have heard, Winnebago has changed the fuse size to 300 amps. I'm inclined to stay with a little smaller fuse to see how it works out. I have a 175 amp fuse currently installed, but could easily change it out to a 200 amp fuse.

My coach has a 300 amp fuse installed for the inverter/converter circuit and the wire size is much larger than the original 125 amp circuit that feeds the rest of the coach and the generator starter. That's the reason, I'm not going to a 300 amp fuse at this time. I've seen posts that indicated both circuits contained the same wire size, but that is not the case in my 2020 Navion.

Bobn1957 · 06-02-2022, 10:28 AM

The wire size defines the maximum fuse that is safe to use! Upping the fuse size without correcting the over-current situation is inviting trouble. Something akin to putting a penny under a glass fuse, "Danger Will Robinson"!

Bobn1957 · 06-02-2022, 10:30 AM

Quote:

Originally Posted by Bobbettyl

Thank you and you are correct. Winnabago did upsize this fuse and didn’t make any general announcement. After blowing 3 fuses my repair shop called Winnabago and found this out. Funny it didn’t blow any fuses for first 2 years. Thanks again

If Winnebego upped the fuse size they must have upped the wire size as well!

Morich · 06-02-2022, 11:39 AM

But isn't this getting into some pretty loose assumptions? Since you have far different RV, is there any reason to think what happens on a Navion will be the same as on a View? Are they even the same year?
Since there are two different generator options on the View, doesn't it make sense that there are quite likely differences in the wiring, since one option is diesel, I would think there might be lots of other things that change as well.

Before jumping in to figure out the problem, don't we really need to decide which year, make, and model of RV, which generator, and which fuse?

I heard one time that we should not relie on "what I heard on the internet" for making very many decisions!

eyecando · 06-02-2022, 07:34 PM

Both the View and the Navion are 2020 units. The View and the Navion are identical. Both made in Forest City on the same assembly line. The only difference is the nameplate which is applied last.

I have a diesel generator, but both the diesel and the LPG generator use the same size fuse. There is only one main fuse that feeds the coach electronics, and that fuse feeds the generator directly. The only other main fuse feeds the inverter/converter and is sized at 300 amps.

Take an ammeter and measure any starter current. You will be amazed at how much current a starter requires to turn even a small engine over. If the fuse is sized below the starter current, it will eventually fail even though they are slow blow fuses. Winnebago has indicated that the 125amp fuse is incorrect.