Help Dead Battery!

[TJ&LadyDi]

Maybe this is the answer; my new replacement fuse!

Note the 3750A rating stamped on it! It came from a power company substation.

TJ

 

[Old-RV'er]

Hmmm, we have on occasion (at least one time-that I can remember) gotten up to around 49A incoming, however, that is with 50A service which all know is really two legs of 120VAC @ 50A per leg. 30A is only 120VAC @ 30A on ONE hot leg. However, it seems to me, that the inverter should have kicked in, to provide the additional current needed to power the two devices, my coach does and has done it lots of times when we were plugged into 30A shore power. We never blew fuse or even tripped breaker. We have induction cooktop, was using one side of that, electric oasis heat both sides, and maybe I started a heat pump to take chill off the rear area. Anyway, nothing blew. Suggest you might take the time to ensure all electrical connections on both chassis and house battery banks are tight. I did that first after getting coach home from purchase. None were lose, but some were not as tight as I wanted, smeared NO-OX-ID-Special A all over them to keep corrosion down. And although situation has been remedied, still think it should not have happened, through inverter it should have been able to handle at least 60A and some of the total load was handled by the 30A SP. Since all receptacles are 15A max, except the microwave is a 20A dedicated circuit. If I remember correctly, mine (cooked chicken on convection) was using about 18A, the cooktop (substitute the air fryer) would use another maybe 13A, 31 total, the inverter should have kicked in. The fuse which blew, was on the DC side of the house, and as such would not have been carrying the complete load of the coach, because the 30A shore power would allow the inverter to "pass through) until it reached 30A and then kicking in providing the other amps needed, no where near the max as shown in another post. So something is not kosher in Denmark based on the explanation so far and the solutions outlined so far. Or, I am completely missing the facts. My guess is, the fuse was not a good manufacturer and/or had some corrosion internal which caused it to fail. Don't think they have date codes, but twas me, if they do, I would make sure I had one with a real current manufacturer date. I have only heard this happening less than 10 times, so this is a rare occurrence.

 

[Jim]

Well great! Glad it was an easy fix.

 

[Akdare]

I can’t really contribute to this thread, but I have read it with interest, just in case...I’m happy you solved the problem...I would still be interested in the root cause of the problem, though.

 

[Neal]

Just remember the induction cooktop outlet is not fed by the inverter and should be used for high amp cooking appliances. It is on the shore power side.

 

[texskeet]

I bought a 350 amp fuss if you ever want to add another inverter so you have 2 with a good solar setup also 300 is to low . 350 is about the same price. That way when you turn your gen you use all of its power. Charge up twice as fast. Less diesel.

 

[CoreyinWP]

The one I blew was a 350. It blew because I did not size wire appropriately. I think there is more to the issue

 

[redbaron]

Maybe this is the answer; my new replacement fuse!

View attachment 1339

Note the 3750A rating stamped on it! It came from a power company substation.

TJ

You almost got me @TJ&LadyDi ! I started to write a post about the danger of oversizing your fuse....then read just how oversized you were going.

2019 DSDP 4369 * Active Air * NHSO

 

[TJ&LadyDi]

You almost got me @TJ&LadyDi ! I started to write a post about the danger of oversizing your fuse....then read just how oversized you were going.

2019 DSDP 4369 * Active Air * NHSO

You are correct about the danger of oversizing a fuse. When circuits are designed, the wire gauge is a significant factor in the fuse size calculation. Upsizing the fuse creates the potential for wiring damage when the fuse does not open at the calculated amperage.

My 3750A fuse is a conversation piece, but won't find itself into the MADP.

TJ

 

[redbaron]

You are correct about the danger of oversizing a fuse. When circuits are designed, the wire gauge is a significant factor in the fuse size calculation. Upsizing the fuse creates the potential for wiring damage when the fuse does not open at the calculated amperage.

My 3750A fuse is a conversation piece, but won't find itself into the MADP. [emoji23]

TJ

Physically..how big is that thing? Looks like it could be the size of a jeep hood, but perspective is absent.

2019 DSDP 4369 * Active Air * NHSO