inverter fuse question - : Jeep Wrangler JK Forum
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post #1 of 4 Old 08-23-2012, 01:38 PM Thread Starter
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inverter fuse question

I just installed a 1200 watt inverter under the driver's side dash. I extended the plugs to the center console and the on/off switch to my SPod... now the question is what size fuse should I put on the main power wires to the battery (I used 2 ga wires to the battery)?

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post #2 of 4 Old 08-23-2012, 02:05 PM
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The inverter should have shipped with a fuse or a breaker. It might be in-line with the provided wiring or installed in the inverter itself.

As shipped it will only protect the inverter, not your Jeep if there's a short in the wiring between the battery and the fuse/breaker.

If there is a fuse or breaker in the inverter, place a fuse as close to the battery one step higher. This will still protect you from shorts while allowing the built-in fuse/breaker to protect the device from overloads. If there is a fuse in-line in the provided wiring, use the same value fuse as provided by the manufacturer at the battery to protect both the wiring and the device from shorts/overload.

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post #3 of 4 Old 08-23-2012, 07:39 PM
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The basic formula to calculate current draw (amperage) is:
W / V = A

That means:
1200 watt invertor.
12 v system.
1200 / 12 = 100 Amps Current.

You should take voltage drop into consideration. If the vehicle voltage were down to 11.5 while you have a device drawing a large amount of current, your draw would increase to 104 amps. When the current draw increases, the voltage will naturally drop. It's all part of that silly stuff they call physics.

I would recommend getting something like a Stinger 150 circuit breaker. The advantage two a circuit breaker is its ease of reuse. A power invertor is a typically a very dirty power source (ever heard that whining sound), and they often have very unregulated power supplies. That will vary its current draw slightly.

Also, the circuit breaker needs to be very close to the battery - i always try for less than 12" - but you need a decent mounting surface, so you just do the best you can given the engine compartment. God forbid there were a short on the hot side of the breaker, you could almost bet a paycheck that you're about to see a fire. The amount of current a 2ga line can withstand on a short run to a battery is extremely high, and that energy is going somewhere - heat.

Stinger Breaker:

They also offer a marine version if you wheel/mud a lot. Is like $20 more or so. Probably worth it.

You can most def use a fuse if you don't want to spend for a circuit breaker. On stingers website, you can find the part numbers to aching you want to purchase - then just eBay it. I don't think stinger sells to the public.

Hope it helps...
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post #4 of 4 Old 08-24-2012, 01:25 AM Thread Starter
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I found a marine grade 150 amp circuit breaker on amazon...would that do the trick mounted next to the battery (within a foot of the battery)??

Found my answer with 300 amp as per the inverter info..

Last edited by njbeachrat; 08-24-2012 at 02:35 AM.
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