# Fuse popping dual 400's



## shej69 (Jul 13, 2006)

Hi guys. One of my compressor fuse keeps blowing. I first had this issue when I had the compressors grounded to a ground distribution block which shares the ground with the manifold and ecu but then I changed the ground point for the compressors to the seatbelt buckle and it worked okay. But just today I put my tank back into the car as I had to redo some fittings. And as it was filling from 0-150 psi the fuse popped again. 

My wiring is the same for the other compressor and that fuse never pops. Both have same branded 30amp fuses on the distribution block. should i change to 40 amps?


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## trixx (Dec 23, 2002)

shej69 said:


> should i change to 40 amps?


yes.


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## UghRice (Sep 8, 2010)

26A max +26A max = 52A max.


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## [email protected] (Jan 26, 2006)

He means 40amp each compressor.

How does it pop, when the compressor starts back up after filling, or on a long fill from 0-150?

also what gauge wiring?


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## shej69 (Jul 13, 2006)

Thanks for the reply guys

Kev heres a diagram of my wiring










Let me break it down, 

From the battery i have a 0awg power cable going to a 200 amp fuse which then continues to a distrbution block

Distribution block has 2 100 amp ANL fuses. One 4awg power cablegoes to my amplifier for sound system and the other goes to another distribution block

So from the 2nd distribution block i have 2 30 amp agu fuses with a 10 awg power cable going to each compressor relay and then to each compressor

Its always the same compressor fuse blowing. the other one never pops.


I was thinking maybe to upgrade the fuse as the accuair power supply comes with a 70amp fuse for the relay giving each compressor max of 35 amps.


when it first started to pop was when the tank used to reach around 130 psi. But when i changed the ground point it did around 6 or 7 fills with no fuses popping. But then as i hooked it all up today it popped when the tank was around 40 psi


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## [email protected] (Jan 26, 2006)

Wiring seems fine.

answer my question, does the fuse blow when the compressor kicks back on with say more than 130 in the tank?

If yes, then you have a bad check valve.

Is it really hot where you live?


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## shej69 (Jul 13, 2006)

[email protected] said:


> Wiring seems fine.
> 
> answer my question, does the fuse blow when the compressor kicks back on with say more than 130 in the tank?
> 
> ...


I've noticed that when the tank is full and I use the air and when compressors come back on after it reaches the 110 psi point it never pops. Only when it's filling from empty tank. 

I live in London and it was pretty hot here today. Around 30 degrees celsius


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## [email protected] (Jan 26, 2006)

Not really adding up to anything in my head. What size of tank?
Why are you filling from 0? Do you have leaks. Does your tank hold air?


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## shej69 (Jul 13, 2006)

[email protected] said:


> Not really adding up to anything in my head. What size of tank?
> Why are you filling from 0? Do you have leaks. Does your tank hold air?


3 gallon tank. I only removed the tank to add on new fittings. It holds air perfectly. I done a bit of reading and it seems it might be a faulty check valve. But the compressor is brand new. How do I check if it's faulty?

Thanks


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## [email protected] (Jan 26, 2006)

I suspect the check valve also, but it usually pops fuse, when it try's to restart under-load.
Take the check valve, off the line, grab some WD-40 and a thin screw driver and see if you can push it back and forth. May take a little work. (I understand its new, it happens to me a lot)


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## shej69 (Jul 13, 2006)

[email protected] said:


> I suspect the check valve also, but it usually pops fuse, when it try's to restart under-load.
> Take the check valve, off the line, grab some WD-40 and a thin screw driver and see if you can push it back and forth. May take a little work. (I understand its new, it happens to me a lot)


thanks kevin. Ill give that a try in the next few days or so.


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## MechEngg (Jan 13, 2009)

shej69 said:


> Hi guys. One of my compressor fuse keeps blowing. I first had this issue when I had the compressors grounded to a ground distribution block which shares the ground with the manifold and ecu but then I changed the ground point for the compressors to the seatbelt buckle and it worked okay. But just today I put my tank back into the car as I had to redo some fittings. And as it was filling from 0-150 psi the fuse popped again.
> 
> My wiring is the same for the other compressor and that fuse never pops. Both have same branded 30amp fuses on the distribution block. should i change to 40 amps?


Each compressor is rated at 26A true, but at 13.8V. When dual compressors kick in simultaneously and start running it can drain the voltage down to ~11 of 12V. If this is the case your amp draw is actually higher to get the same power to your compressors.

Power = Voltage x Amperage
Amperage = Power / Voltage

so for 1 400:

Power = 13.8V x 26A = 358.8Watts

Converting back for only a 12V voltage 

Amps required = 358.8Watts / 12V = 29.9A

Therefore if your voltage ever goes below 12V your fuses will start to pop. There are some variances in the manufacturing of the fuses and all are usually +- a certain % so a 29.9A draw could blow some fuses and not others. 

I would recommend just switching them up to 40A. Honestly you won't hurt anything by doing this, you have dual protection from both the fuses and the relay.


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## shej69 (Jul 13, 2006)

MechEngg said:


> Each compressor is rated at 26A true, but at 13.8V. When dual compressors kick in simultaneously and start running it can drain the voltage down to ~11 of 12V. If this is the case your amp draw is actually higher to get the same power to your compressors.
> 
> Power = Voltage x Amperage
> Amperage = Power / Voltage
> ...


ahh that explains it then. Thanks. Im going to check the voltage drop with a voltmeter and see if it does go to around 12v.

Thanks again


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