Cart dead - blown ANN fuse

Dixie Chopper

Kids were riding for a while today in high grass / some mud and the cart died. First thing I checked was power to the controller - no green light. Checked voltage on each side of the ANN 250 fuse that came with the Alltrax from scottyb and sure enough it’s blown. Battery pack voltage was on the low side when it happened (36. so it was definitely running low but I don’t think that’s the reason it blew.

I’m thinking that the way I had the fuses mounted it was probably flexing and caused some stress on the fuse itself. I changed the way It’s mounted now to eliminate that. I went to Autozone looking for a replacement and all they had was a 175A auto fuse. I figured what the hell, being a lower amperage rating it can’t hurt, right? I ordered a replacement on amazon and put the 175 in there and powered it up and it looks good. I haven’t tried to run it yet because it’s charging.

Anything else that I need to look at or do before trying to run it? I figure the 175a fuse will blow at some point but maybe we can take it easy until the replacement arrives.



After —-

BGW

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JohnnieB

It takes the same Watts to move the cart at a given speed, so more Amps have to be drawn to do the same job when the battery pack voltage is low. (Watts = Volts X Amps)

What makes a fuse blow is a combination of Amps and time. An ANN250 will pass 250A forever, 400A for about 100 Seconds and 1,200A for about 0.01 second, so there was a fairly high amp draw for a relatively long period of time. IE: driving through mud at a low speed.

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The stacking on you new fuse install is wrong.

Fuse to controller goes on first (Bottom of stud), fuse from charge port goes on second and red wire goes on last.

highest amp draw connection should be in the most intimate contact with the battery terminal.

Attached Images

ANN fuse specs.jpg (234.2 KB, 0 views)

Dixie Chopper

Great info as always Johnnieb! So am I good to run it on the 175 amp fuse temporarily?

kgsc

Until it blows :) If you have any high end car stereo places around they usually have those fuses.

Dixie Chopper

I didn’t think about a car stereo place. Thanks!

cgtech

That fuse is known to flex the elements inside until they stress crack. I doubt it was drawing the kind of load required to blow that fuse. As noted above, the rating is not a "hit this amp level & it blows", it's a slow acting fuse that requires a super heavy load for longer times (like a totally shorted out system).

Dixie Chopper

That could have been the case here with the way I had them mounted. Or a combination of that and heavy load/low batteries

JohnnieB

Probably a combination of both. Physically damaged by flexing, reducing the ampacity, then heavy electrical loading.