HALP! Am I wiring my toggle switch correctly?

[fuzzybabybunny]

Is this correct? I'm trying to wire an illuminated toggle switch to control a 500W inverter which will be mounted in the back.

EDIT: The box on the left is the battery.

 

[CurseTheSky]

Wiring that switch should be the least of your concerns. Your pet fish has a very serious - lethal in fact - case of worms, and it apparently passed them on to your car. Your pet ostrich also ate your tire but felt bad and left an egg in its place.

I suggest you call a mechanic, vet, and exorcist, in that order.

 

[ecom]

I strongly advise you use a relay and fuse, but your diagram looks right. You can just use the chassis ground though. No need to run a negative wire like that.

 

[fuzzybabybunny]

I strongly advise you use a relay and fuse, but your diagram looks right.

Right, I've got a 30A fuse connected as close to the positive terminal of the battery as possible.

CAN the ground of the switch just be attached to the frame? Or does it need to be attached to the negative on the battery?

Why can't the negative on the inverter just be attached to the frame as well?

 

[ecom]

See my edit re the neg connection. The neg on the inverter can be attached to chassis - ensure you use the same gauge wiring as the positive.

Is that 500W the input or output? Either way, that 30A fuse is insufficient. You might blow it fairly quick.

500W/12V = ~42A

Since I don't anticipate that the inverter is 100% efficient, the current will be higher than 42A. You'll probably need a 50 or 60A fuse. At which point I would suggest you use 4AWG.

I hope you are using at least 8AWG or 4AWG wire.

Use the switch to control the relay and the relay will handle the current between the battery and the inverter. It may be difficult to find a switch that will handle the current you need.

This one should work.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=075-140

 

[Howard]

Wiring that switch should be the least of your concerns. Your pet fish has a very serious - lethal in fact - case of worms, and it apparently passed them on to your car. Your pet ostrich also ate your tire but felt bad and left an egg in its place.

I suggest you call a mechanic, vet, and exorcist, in that order.

i'd uprate this post if I could

 

[fuzzybabybunny]

Gotcha.

I will NEVER run 500W. I have used this inverter for years on my old Echo and have never even come close to 500W. The most I've ever used is 300W - 200W sub and 100W computer, and I've always used just 12AWG wire. The inverter itself has dual 30A fuses on it already. I could not find higher than 30A blade fuses at radio shack today either.

 

[MotF Bane]

Wiring that switch should be the least of your concerns. Your pet fish has a very serious - lethal in fact - case of worms, and it apparently passed them on to your car. Your pet ostrich also ate your tire but felt bad and left an egg in its place.

I suggest you call a mechanic, vet, and exorcist, in that order.

LMAO. You win the thread.

 

[ecom]

 

[ecom]

Gotcha.

I will NEVER run 500W. I have used this inverter for years on my old Echo and have never even come close to 500W. The most I've ever used is 300W - 200W sub and 100W computer, and I've always used just 12AWG wire. The inverter itself has dual 30A fuses on it already. I could not find higher than 30A blade fuses at radio shack today either.

The fuse by the battery is to protect the wire not the device attached to it. The fuses on the inverter are to protect itself.

How long is the 12AWG wire you are using and did that come w/ the inverter? For a 15ft run, I would say if you are running more than ~25A, you will have more than 0.5V drop on this wire. For amplifiers, this is very undesirable.

I've never wired an inverter, or used one before, I am answering your question based on my experience from installing amps. But if it is working, then I will not argue with you about it.

 

[fuzzybabybunny]

The fuse by the battery is to protect the wire not the device attached to it. The fuses on the inverter are to protect itself.

How long is the 12AWG wire you are using and did that come w/ the inverter? For a 15ft run, I would say if you are running more than ~25A, you will have more than 0.5V drop on this wire. For amplifiers, this is very undesirable.

I've never wired an inverter, or used one before, I am answering your question based on my experience from installing amps. But if it is working, then I will not argue with you about it.

Well, this is the first time that I've had to mount my inverter all the way in the back of the car - in my old car it was right there in the cabin, so wires weren't too long. What exactly would happen if I run too long of a wire with too small a gauge? What would that voltage drop do?

 

[ecom]

You might have up to 1.5V drop with 12 AWG for 15 ft length compared to the potential at the battery. You won't see it when there is no load (open voltage), but start running your items then you might see the voltage drop.

I'm not sure what effect this will have on the inverter. My guess is that any of the following can happen:
- Inverter thinks battery is dying and shuts off to protect battery
- Excessive pos. wire heating
- Inverter outputs lower voltage
- Inverter works less efficiently (same output but requires more input) so it heats up more

I strongly advise you use 8AWG instead and no more than 50A fuse for a 15 ft run. For 15ft 12AWG run, it should be fused at 20A.

See http://bcae1.com/ section 16. Wire for lots more info.

 

[NutBucket]

Follow the advice here. Otherwise, your next thread may go something like this:

"How the car-bq started..."

 

[fuzzybabybunny]

You might have up to 1.5V drop with 12 AWG for 15 ft length compared to the potential at the battery. You won't see it when there is no load (open voltage), but start running your items then you might see the voltage drop.

I'm not sure what effect this will have on the inverter. My guess is that any of the following can happen:
- Inverter thinks battery is dying and shuts off to protect battery
- Excessive pos. wire heating
- Inverter outputs lower voltage
- Inverter works less efficiently (same output but requires more input) so it heats up more

I strongly advise you use 8AWG instead and no more than 50A fuse for a 15 ft run. For 15ft 12AWG run, it should be fused at 20A.

See http://bcae1.com/ section 16. Wire for lots more info.

VERY cool website.

Question:

I'm doing the speaker wire calculator:

http://bcae1.com/wire.htm

Power Output: 400W (higher than actual usage)
Speaker Wire Length: 20ft (5ft longer than actual)
Speaker Wire Guage: 12
Load Impedence: 4ohm?

Results:

Current Flow: 9.84A
Speaker Wire Resistance: 0.0635
Voltage Drop: 0.63

Would something like this really put me in danger of igniting my car on fire?

General Questions:

Can I use a smaller gauge wire as long as it's not run for very long? Wiring an 8AWG wire from the battery, through the firewall, and into the cabin would be a pain in the ass, no? Now I've got a 5 foot long 12AWG wire doing this.

I would use 8AWG or thicker for the rest of the wiring.

Damn, I've already done all the wiring already. This is going to be a pain in the ass.

 

[ecom]

I don't know what effect this will have, but personally, for no other reason than safety, I wouldn't do that unless the circuit is fused as if I were using the smaller wire for the entire run, 20 or 25AWG in this case. Which brings up the issue of how are you going to splice this wire mid-run? 8AWG is a big wire and really I'd only use solder and heatshrink if it were going inside the vehicle.


I tink you are better off with the no. 3 or 5 calculator on the wires page. I don't know what efficiency your inverter has, but my guess is maybe 80%. I say 80% because that's about the typical efficiency of a class D amp which is typically only used as a subwoofer amplifier. The output from the inverter would be around 50-60Hz sine or approximated sine wave (which is in the range of a sub). Hrm...interesting that in some ways I can think of an inverter like an amp .

 

[fuzzybabybunny]

Damn, how AM I going to splice this? I've already spent so much money on wires that are too damn thin and the quick disconnects and the wire crimping tool.

Do they make quick disconnects for 8AWG?

 

[ElFenix]

camera charging and computer station in your trunk?

 

[NutBucket]

Eh, 8ga through the firewall isn't bad. Get back to me when its 0 gauge Personally the largest I've done is 4, but that's all that was necessary. 8 is still fairly easy.

 

[fuzzybabybunny]

How about this:

When I actually get my new headunit and can install the sub, I run the sub and laptop at once and sit there to check the existing wire for heatups. If it heats up, I go replace the wires, probably with one of those ready-made amplifier wire kits.

The sub is just an 188 RMS sub from a Logitech Z-5500.

 

[ecom]

If the sub is actually188W RMS, you might need like 250W input power to the amp and then 320W into the inverter depending on the efficiencies of the the equipment you are using.

You are better off getting a multimeter and looking at the voltage drop than checking for heating of the wire.

I've never done 0 gauge -- only 4 gauge also.

 

[fuzzybabybunny]

If the sub is actually188W RMS, you might need like 250W input power to the amp and then 320W into the inverter depending on the efficiencies of the the equipment you are using.

You are better off getting a multimeter and looking at the voltage drop than checking for heating of the wire.

I've never done 0 gauge -- only 4 gauge also.

How do I do this?

Grab a multimeter and then place the leads on the + and - on the inverter, record the voltage, then place the leads on the + and - on the battery, then take the difference in voltage?

 

[NutBucket]

Ugh. Must you be so ghetto? Can you really not afford a few hundred bucks for a real sub?

Hell, even this would be significantly better:
http://www.amazon.com/Boss-BASS600-L.../dp/B000OSZA44

This is the best powered sub I've heard:
http://signature.crutchfield.com/s_108BASSLIN/Infinity-Basslink.html?tp=114

EDIT: Yes, that's how you measure voltage. The voltage at the battery should be 14.4 when the car is running. Ideally, you want about 14 or so at the inverter.

EDIT 2: Highly doubtful that sub is a real 188W RMS. Just sayin'

 

[fuzzybabybunny]

Ugh. Must you be so ghetto? Can you really not afford a few hundred bucks for a real sub?

Hell, even this would be significantly better:
http://www.amazon.com/Boss-BASS600-L.../dp/B000OSZA44

This is the best powered sub I've heard:
http://signature.crutchfield.com/s_108BASSLIN/Infinity-Basslink.html?tp=114

EDIT: Yes, that's how you measure voltage. The voltage at the battery should be 14.4 when the car is running. Ideally, you want about 14 or so at the inverter.

EDIT 2: Highly doubtful that sub is a real 188W RMS. Just sayin'

If I don't use the Logitech, it's just going to sit there as a paperweight. I can't use subs where I live (baby in the house) and the satellites actually had their cones melted from gasoline vapors.

 

[NutBucket]

Sorry, still bad reasoning

 

[jlee]

If I don't use the Logitech, it's just going to sit there as a paperweight. I can't use subs where I live (baby in the house) and the satellites actually had their cones melted from gasoline vapors.

Sell it on craigslist and buy the right stuff.