RTV blown fuse

[Tact]

Last night I plugged in a Q-Beam spotlight in the 12V accessory plug and it blew the 10amp fuse in the box. I would have thought this should have worked without a problem. Anyone have a suggestion as to what I need to do to be able for the spotlight to work in the RTV? It must be drawing too many watts.
I assume I'll have to run a separate plug directly from the battery.

 

[bczoom]

Tact,

I don't have anything with me right now but a couple thoughts/questions.

Do you know how many watt bulb is in that spotlight? Some of the larger Brinkmann's can pull close to 10 amps which is your max out of that socket. I believe their 1M CP pulls about 8 amps.

I don't think Kubota recommends you put in a larger fuse as the wire then becomes the weak point.

What else is on that fuse?

Myself, I put another 12v plug on mine that is rated for 20 amps.

Brian

 

[Tact]

Brian,
I think that's what I'm going to have to do. I'll just run a different plug directly from the battery and probably put about a 30 amp inline fuse. I imagine 10 ga. wire would work?

Fred

 

[DaveNay]

Brian,
I think that's what I'm going to have to do. I'll just run a different plug directly from the battery and probably put about a 30 amp inline fuse.

Fred

You might want to try switching to a slow-blow fuse of the same size first. Only a buck or two, and easier than modifying the electrical.

 

[bczoom]

You might want to try switching to a slow-blow fuse of the same size first. Only a buck or two, and easier than modifying the electrical.

Dave,

If the spotlight is at or above the rated wattage and the fuse doesn't blow does he risk something elsewhere?

Fred,

Are you going to replace the accessory plug or put in a 2nd one? I wouldn't use the one that's in there since it's too light for the load. As I recall, the wires were real small.

If/when you do pull a new wire, you might want to consider a way to split it for future use. When I pulled mine, I ran 50 amp then split it off for the accessory plug, aux lights, stereo...

 

[Tact]

Dave,

If the spotlight is at or above the rated wattage and the fuse doesn't blow does he risk something elsewhere?

Fred,

Are you going to replace the accessory plug or put in a 2nd one? I wouldn't use the one that's in there since it's too light for the load. As I recall, the wires were real small.

If/when you do pull a new wire, you might want to consider a way to split it for future use. When I pulled mine, I ran 50 amp then split it off for the accessory plug, aux lights, stereo...

That makes more sense in case I do decide to run other accessories later.
And yes, I am going to run a 2nd plug.
Is 10 ga. large enough wire?

 

[bczoom]

Is 10 ga. large enough wire?

How many amps do you want to handle? I think 10 gauge can handle 30 amps.

I ran 4 or 6 gauge for my 50 amps.

 

[johnday]

Yes, #12 wire is good for 20 amps, #10, 30 amps. Then #14 goes to 15 amps.

 

[Tact]

Brian,

Did you run 6 ga. the entire way or did you run 6 ga. to the fuse and then stepped it down to smaller ga. wire to each accessory?

 

[DaveNay]

Dave,

If the spotlight is at or above the rated wattage and the fuse doesn't blow does he risk something elsewhere?

Yes.

However, if the light is actually rated at an acceptable load, and it is still blowing the fuse, then it may be the inrush current. Resistive loads sometimes have a higher current draw on startup, and then after they heat up in a couple hundred milliseconds, they settle down to their rated load. A slow-blow fuse will be able to handle this momentary load with no damage to the rest of the circuit.

Of course, the surest is to add the second circuit at a higher rating, and if you are more comfortable doing that, then by all means go ahead.

 

[Junkman]

If the tractor spends any time outside in damp weather, use marine grade wire instead of automotive wire. Less likely to have corrosion problems. I would use 12 gauge wire and a automatic resetting circuit breaker. They can handle the surge current better than a fuse. Remember you are wiring a tractor, not a house, so if you need anything larger than a 12 gauge wire, you need to have another dedicated circuit. It is rare to see anything larger than 12 gauge on any automotive type of equipment with the exception of the starting circuit. The more wires in the bundle, the better the quality of the wire. Just buy the best that you can find, because the price difference isn't going to be much.
Junk...

 

[bczoom]

Brian,

Did you run 6 ga. the entire way or did you run 6 ga. to the fuse and then stepped it down to smaller ga. wire to each accessory?

Fred

I ran 6 gauge with an inline fuse to a terminal block.
From there, I ran smaller wire to each of the switches/accessories.
Yes, I believe I ran 12 ga the rest of the way.

 

[Junkman]

I can't imagine a 6 gauge wire with a fuse in line...... better check the size of the wire again. Anything that large would have either a giant circuit breaker or more likely a fusible link, but not a fuse. Junk........

 

[bczoom]

Junk,

Unfortunately, I can't get to the area to take a pic but I'm running an inline 50amp Maxi Fuse in a waterproof holder.

As best I can tell, Junk is correct. I cannot find the holder in 6ga. I found on the internet 10ga with the 50amp fuse but as already noted, that's not right (and I may have a problem although everything I have now doesn't come close to 50 amps).

If/when I get back into the area, I may have a re-do and switch the whole fuse and terminal block out for a single fuse block with a 50 amp main fuse.

Remember you are wiring a tractor, not a house, so if you need anything larger than a 12 gauge wire, you need to have another dedicated circuit. It is rare to see anything larger than 12 gauge on any automotive type of equipment with the exception of the starting circuit.

Junk,
Here's a couple pictures.
The one shows some of the ceiling panel area. Between the ceiling and roof panels is where all the wiring resides. You can see the 10 (marine grade) switches to run various components.
The other shows the conduit I ran the wires in. There's a 6ga hot and ground in there. Down near the battery (I don't have a pic of it) is a large throw type disconnect for the power.

 

[Junkman]

My ambulance has more power drain than any tractor that I can conceive of having. There is no one wire other than the supply to the starter that is greater than a 10 or 12 gauge wire. The fuse blocks are supplied with power from a master battery disconnect terminal and then the power goes to the individual circuits that are protected by individual circuit breakers. As an example, if I were to make a hot run with all lights and siren going for 20 minutes, that would be enough to kill both batteries. The alternator puts out 220 amps and the batteries are both extremely large. This is why you don't ever see them shutting down the fire truck, ambulance, or police cars, because if they do, they might not get them started again. This drain will suck a system dry, but never overload the wiring of the system.
If you were to add up the total amount of amperage that each circuit breaker in your home electrical panel and compare that to the total amperage service that supplies that panel, you will see the disparity. 200 amps might be what supplies the panel, but the total breaker capacity might be 1000 amps or more. You will never draw that much all at once, so there is never a problem. Same with your tractor, it is doubtful that you will ever draw the full capacity. Remember, the fuse or circuit breaker is designed to protect the wiring from over current, not the device.