Why would this fuse be blowing all the time?

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phoenix
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Why would this fuse be blowing all the time?

Details:
XB-600
Shunt mod: yes
5th battery: yes

Why would the glasss fuse blow? (What's the amp rating on the fuse, btw?)

It took all my lights with it. Now, whenever I replace the fuse and turn on the lights, the fuse blows instantly. I haven't done any wiring work at all. Not sure if this means a bare wire is shorting against metal somewhere.

I can't ride at night without lights. WHy would that fuse blow so quickly?
Thanks all.

phoenix
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Re: Why would this fuse be blowing all the time?

I needed to add a question here. Where can I find replacement bulbs?? Kragen's doesn't have them. Help?

68snewpy
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Re: Why would this fuse be blowing all the time?

Does the fuse blow while driving or while parked with the motor off?
The fuse should be marked what rating it is.

captainslug
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Re: Why would this fuse be blowing all the time?

The brake light and headlights are regular 1157 bulbs.
//autorepair.about.com/library/graphics/bulbs2.jpg)
The only difference between them is that the headlights are halogen bulbs.

phoenix
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Re: Why would this fuse be blowing all the time?

The fuse blows when the ignition is on, bike is stationary and the lights are flipped on. And the lights did act as fuses. Brake light, headlights totally shattered when I put in a fuse rated at over 15 amps. I think I very nearly fried my electrical system but didn't. I removed the fuse and my bike still runs, just without any lights.

BUT, Why would the fuse short out in the first place, tho?

frodus
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Re: Why would this fuse be blowing all the time?

don't listen to ANYONE that tells you to replace a fuse with a shorting plug (aluminum rod).

Its just plain stupid...

Fuses are there to protect what is DRIVING the bulbs as well as the bulbs themselves. If there's a short somewhere, and you shorted the fuse on the output of the DC-DC converter, if it doesn't have current limit protection, you could have just fried the DC-DC converter.

If you shorted it, and the bulbs all blew, SOMETHING isn't regulating the voltage. The current is regulated on bulbs with their filament. If its a 12V bulb, it will only draw xxxAmps. If you're over 12V, it might overload the bulb and blow.... which sounds like what happened.

Sounds to me that you should check the voltage output of the DC-DC converter and make sure that its regulating at ~12V.

____________

Travis Gintz
1986 Honda VFR Conversion
www.evfr.net

captainslug
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Re: Why would this fuse be blowing all the time?

But DC-DC converter can only output up to it's maximum supply rating.
The included fuse is not enough to handle the initial power draw of the lights.
It should be a 15amp fuse instead of a 10amp.

frodus
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Re: Why would this fuse be blowing all the time?

But DC-DC converter can only output up to it's maximum supply rating.
The included fuse is not enough to handle the initial power draw of the lights.
It should be a 15amp fuse instead of a 10amp.

First off: Some DC-DC converters are not very good at current limiting. Some limit current by increasing voltage. You can't depend on the DC-DC to ONLY supply 10A. If there's a short, or something is drawing more... it'l just go into current limit. Do that long enough and its gonna be pretty hard on the converter. Something with his system is NOT right. You told him to "short" across the fuse block, so nothing is protected. if a bulb is 12V and gets a 12V supply, it'l only draw its rated amps. If something isn't right, and the voltage is too high, the bulb draws more amps, and you just removed the fuse so now the bulb blows. If there was a short, and there's something wrong, you just removed any protection he had.

I work with DC-DC converters all the time (vicor, artesyn, etc.) and I can tell you for a FACT, they they're not all equal. ESPECIALLY if they're not isolated (3 wire devices). 4 wire devices (isolated input/output) are a little better at current limiting. I haven't seen a 3 wire that hasn't died/stopped regulating within 3 months... they are built as cheap as possible.

Second: So, they included a fast blow fuse? then replace it with a slow blow fuse that will take the initial inrush current of the lights, but protect against a continuous 10A load. That way you're protected. If it blows with a slow blow, contact the manufacturer. If its a slow blow, make sure the wiring is right and that the total load is below 10A.

Why do you say it should be 15A? Have you measured the current after the bulbs have stabilized to see what all the lights draw? One other thing, are you sure you replaced the bulbs with the same wattage bulb and not "just one that fits"? Sometimes the bayonette is the same, but it could be a 50W bulb, but the original was 25W. 50W draws twice the amps, in the same size bulb.

Just be sure you have all your ducks in a row before you tell someone to remove a devices that is designed to protect things from burning/heating up/destroying they're equipment.

I'd be more concerned that 5 batteries are going to the DC-DC converter... isn't that over its voltage range?

____________

Travis Gintz
1986 Honda VFR Conversion
www.evfr.net

frodus
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Re: Why would this fuse be blowing all the time?

OK, did some research:

Its a 48V to 12V converter. If you drive it with 60V, it could be over its limit when you have a fully charged pack (13.8 per bat is 69Volts). Its also a 3 wire system too, so its non isolated. The converter should NOT be run off the 60V pack, it should be tapped at 48V.

http://visforvoltage.org/forum/4275-72v-35mph-xtreme-xb-600-video-link-here#comment-24638

Someone also had a short:
http://ecomodder.com/forum/showthread.php/xtreme-xb-600-a-5158.html#post70436

____________

Travis Gintz
1986 Honda VFR Conversion
www.evfr.net

captainslug
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Re: Why would this fuse be blowing all the time?

Plenty have used the DC-DC converter with a 60V pack. If you were to go to 72V you definitely would need to replace it. But you're on the right track. The easiest way to really kill a DC-DC converter is to supply it with more power than it can handle.

And that thread on Ecomodder is me. :)

frodus
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Re: Why would this fuse be blowing all the time?

hehe, nice.

well, in the end, the right voltage (its made for 48V) and protecting it right are my main concerns.

He said the bulbs "shattered"... so I'm curious about the voltage output of the DC-DC converter.

____________

Travis Gintz
1986 Honda VFR Conversion
www.evfr.net

richardb
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Re: Why would this fuse be blowing all the time?

The fuse blows when the ignition is on, bike is stationary and the lights are flipped on. And the lights did act as fuses. Brake light, headlights totally shattered when I put in a fuse rated at over 15 amps. I think I very nearly fried my electrical system but didn't. I removed the fuse and my bike still runs, just without any lights.

BUT, Why would the fuse short out in the first place, tho?

OK, the above statement is a clue that you have a faulty 12V regulator. Your headlights and taillights, if they are 1157 bulbs, draw a total of less than 8 amps at 12 volts. If they all shattered, and blew a 15 amp fuse, then the regulator must be furnishing more than 12 volts. Buy a new regulator, OR.... Wire in a 12 volt battery in place of the regulator and charge it with a separate charger.

By the way, my XB500 does not use 1157 bulbs for the headlights, it uses a flanged bulb. I replaced them (two of them) with LED bulbs, which are far brighter, and draw only 0.5 amps for the pair.
Dickey_b
Waste Not, Want Not

Dickey_b
Waste Not, Want Not

phoenix
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Re: Why would this fuse be blowing all the time?

thank u for all the replies.

All of what you have been saying is probably true but over my head. "I drive 'em, but i don't understand 'em."

I found a problem that might be connected to this. While riding to work one morning, the motor started to whine and it suddenly stopped rotating. The bike came to a very rough stop and I could barely push roll it onto the sidewalk.

I looked under the seat and saw that the three wires that connect from the motor/hub to the controller (yellow,blue,green) had completely fused together. Ya, thats right. Fused. Somehow the wire connects burned through the clear casing and all three wires touched, burned out and fused. Then the motor seized and there was a terrible burning electrical smell.

Question one: Is the motor fried and will i need a new one?
Question two: How can I keep this from happening again?

Thanks.

68snewpy
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Re: Why would this fuse be blowing all the time?

Carefully inspect the rear axle to be sure it didn't spin and twist the motor leads. The other possiblity is your putting too much power through the relatively small gauge wires. Either way you'll have to open up the motor to check for damage but likely you will just have to replace the wires (not as easy as it sounds).

TechSkeptic
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Re: Why would this fuse be blowing all the time?

ok, I realize I am late to the party here, but more information isn't worse...right?

anyway I have an XM-3000 with your exact symptoms. Bike runs, but no lights.

Turns out, for me, it was not a short somewhere in the system. When I check continuity down stream of the DC converter, I don't detect one. However when I took a look at my DC converter, it is all discolored around one edge. I suspect, that water got into the potting of the converter. I lknow the compartment DID get water in it, but it was hard to believe that the potting didn't prevent water from getting into the Dc converter circuit. However, what can I say? it looks like crap, I have to replace it.

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