cheesyhoward

I currently use an inverter to power my car mp3 player. In my old car i had the inverter mounted under the drivers seat and ran a 120v power lead to the computer in the boot (switched on manually). This worked fine. I now have a new car and decided to mount the inverter in the boot with the computer. I purchased a relay with a 30amp fuse on it. I installed a switch that ran off the ACC line to the relay (pin 85) and connected a ground (pin 86) to it also. I connected 10guage power wire from battery (fused at 35amp) to the power input (pin 30) and the other pin 87 to the positive input on the inverter. I connected the negative input on the inverter to chassis. The problem is as soon as the relay is switched on the fuse blows on the relay. Is this because the relay is fused at 30amp while there are 35 amp fuses in the inverter and at the battery connection? The fuse blows when the inverter circuit is connected but before it is switched on at the switch on the inverter. I have not tried higher rated fuses in the relay because i didnt want to risk blowing my inverter. There are no obvious short circuits that i can see. Any help would be appriated as to what i am doing wrong. Cheers

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Telek

Fuses will only blow as soon as you turn something on if there is a short somewhere. Drawing 30 amps from your 12V battery is a LOT of power (360W) for anything, so you MUST have a short... My guess would be that you've certainly got the relay hooked up wrong, what type of relay are you using, and why does it have so many pins? If you hook everything up to the inverter directly, will it blow the other fuse?

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Aaron Cake

Sounds like your relay is connected wrong. Do you have a schematic or something demonstrating how you have things hooked up? Fuse ratings really have nothing to do with this.

Oh, and this topic has been moved to "Power Supplies".

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lucho

86 12v ACC (Blue)
85 Ground (Black)
87 Inverter (Red)
30 12v Battery (Yellow)

Lucho

craigyb

Check this link out for how to wire up your relay.... but based on what you have told us it looks correct.

http://www.the12volt.com/relays/relays.asp

The first fuse 30A will always blow before the 35A inverter fuse as its got a lower rating, as your inverter is protected by a 35A fuse, why do you need the 30 amp fuse on the relay. I would get rid of that first fuse, that will tell you if you have a problem with the inverter

Craig

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rgardjr

That looks correct. Not that I have much experience with relays, but I've never seen one with a built in fuse-I have seen them with built in diodes. You've actually got 3 fuses involved, correct? One 35 amp coming from battery to pin 30, one on relay between pins 30 and 87, and one built into the inverter itself. How much power is the inverter rated for? What happens when you try the inverter without the relay involved?

Rob Withey

I think after 2 1/2 years it's probably either been sorted or abandoned.

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