air compressor blowing fuses

[swynx]

Bought a viair compressor last winter, can't remember the model . Its rated for 33 inch tires. It hooks up to the battery and came with a 20 amp fuse. I get about 5 uses out of it before the fuse blows. But each time it seems to get worse. This last time it actually melted the housing.

It never pops while using. I always find the burnt fuse when I go to use it the next time. I think the instructions said to use it with the engine running. It runs better with the engine on. Idk if thats what is causing it.

Opinions?

 

[wizkid00104]

Bought a viair compressor last winter, can't remember the model . Its rated for 33 inch tires. It hooks up to the battery and came with a 20 amp fuse. I get about 5 uses out of it before the fuse blows. But each time it seems to get worse. This last time it actually melted the housing.

It never pops while using. I always find the burnt fuse when I go to use it the next time. I think the instructions said to use it with the engine running. It runs better with the engine on. Idk if thats what is causing it.

Opinions?

Is it always hooked to the battery, or only when you are using it? Where is the fuse? On the truck or built into the compressor?

 

[RonD]

I would guess the motor in the compressor was marginal when you got it, bad assembly may be, make sure it is a 12volt model not 24volt.
I have never used a viair compressor so can't say if it is "normal".

Was the original fuse a "slow blow" type?
If so then a regular fuse would tend to blow more frequently, slow blow type allows a few spikes of heat as 'normal" operation, similar to fusible links.

Startup current for an electric motor will spike current draw, this can blow a marginal fuse(already close to blowing) instantly.

But if "housing" melted then there is for sure an issue with current draw, not simply a bad or wrong type of fuse.
Do not use a higher amp fuse, that will just melt the wire as it will become the "fusible link".

 

[Captain Ledd]

The fuse may be marginal too. I don't know the draw or amperage rating BUT, as voltage goes down, Amperage goes up to compensate.

If you had a motor that could be wired for either 110v or 220v, and the 110v circuit stated it drew 10 amps, on a 220v circuit it would draw 5 amps.

So as your battery drops in voltage, the amperage will increase slightly and it might be just enough to pop things or run them near the very edge.

My Viar has gone through only one fuse, but it was an old round tube one from the 70's I wired that was in my dads old misc electrical box, and it's bouncing around loose as I still haven't made a permanent mounting solution. So I'm not sure how much I can fault it.

Though it sounds like there might be something else going on, exactly what compressor do you have?

 

[enjr44]

An electric motor needs a certain amount of power to run. Power = Watts. So if the input voltage is low the current draw will be higher and that will = more heat (motor will get hot). A fuse does not care what the voltage is, it current sensitive, so low voltage will cause high amps that will in turn blow fuse when its little wire gets hot enough to melt.

My guess is you are getting low input voltage from the battery to the pump.

Sorry, just saw Captain Ledd's post that is saying the same thing, LOL.

 

[swynx]

The pump is portable so not hooked up permanently. The fuse is on the wire leading to/from the pump. Monday ill snap some pics of the compressor and respond with more information.

Something is wrong as I have probably replaced the fuse about 5 times.

Edit... pretty sure this is it.

http://www.amazon.com/gp/aw/d/B005ASY23I?tag=959media-20

 

[Captain Ledd]

For some reason I can't get anything but a text only page to come up, and it still didn't list much specs. Is this the unit in question?

http://www.viaircorp.com/88P.html

Sorry, just saw Captain Ledd's post that is saying the same thing, LOL.

LOL, I barely made it in before your you. I posted, backed out to the main forum page, reloaded, and it said someone had already replied.

Along those lines, I suspect that might be the problem. The battery is dropping juuust enough voltage and upping the amperage to give the fuse problems. Occasionally not quite enough to pop it, but make it really, really hot, which would also weaken the fuse over time. You said it does run better with the vehicle running, might be for the best to just eat a few minutes of gas, it's certainly better than melted housings and a non-functional air compressor when you actually need it. If you still have issues with fuses (certainly not melting ) I'd promptly contact Viair.

 

[RonD]

battery voltage engine off = 12.5v
battery voltage engine running with load = 14.5v

Say your compressor motor requires 250watts, look on the label
At 12.5volts that is a 20 amp draw
At 14.5volts it is a 17.25 amp draw

If battery voltage drops to 11.5v while using compressor you go to 21.7amps

 

[enjr44]

Viair says it is a 12 volt unit; but, all of their listed specs are for a 13.8 input voltage. And you won't get that without the engine running.

Just saying.

 

[vance44]

Hey can someone me if the 1998 ranger 3.0 L engine will work in a 1993 Ranger XLT

 

[RonD]

Hey can someone me if the 1998 ranger 3.0 L engine will work in a 1993 Ranger XLT

Click on this link: http://www.therangerstation.com/forums/forumdisplay.php?f=12

Then click on "New Thread" just below banner and above "stickies"

Then post your question.

What you have done in this thread is called a "high jack", you have, in essence, spit in the face of the person who started this thread to get answers to their questions.
This is a polite response to your high jack, others might not be so kind.........
But it is your first post here so.....some slack has been cut, lol.

 

[Chris_North]

The fuse may be marginal too. I don't know the draw or amperage rating BUT, as voltage goes down, Amperage goes up to compensate.

If you had a motor that could be wired for either 110v or 220v, and the 110v circuit stated it drew 10 amps, on a 220v circuit it would draw 5 amps.

So as your battery drops in voltage, the amperage will increase slightly and it might be just enough to pop things or run them near the very edge.

An electric motor needs a certain amount of power to run. Power = Watts. So if the input voltage is low the current draw will be higher and that will = more heat (motor will get hot). A fuse does not care what the voltage is, it current sensitive, so low voltage will cause high amps that will in turn blow fuse when its little wire gets hot enough to melt.

My guess is you are getting low input voltage from the battery to the pump.

Sorry, just saw Captain Ledd's post that is saying the same thing, LOL.

I don't believe this is entirely accurate.

With AC motors (and other inductive loads) this is correct. Any decrease in voltage and the motor will require more current to continue to be able to output the same power. I can't remember exactly, but I don't think DC motors behave the same way. IIRC a DC motor is akin more to a resistive load: an increase in voltage means an increase in current and vice versa.

The best I could do support my flaky memory was to hook up an old drill motor to a power supply I made. With no load both situations it drew 1.7 Amps at 12V and at 24V it pulled 2.4A. I wish I had something more black and white than that, but this was the best I can do.

Brushed DC motors' RPMs are purely dependent on the voltage being supplied and the load on the mechanical end of things. This is why the compressor may seem to run "better" when the engine is running; the increase in voltage provided by the alternator is causing the motor to run faster. It is likely pulling more current this way. The typical AC motors (synchronous, IIRC) depend on the frequency of the AC waveform (in addition to the design of the windings) to determine their operating speed. This is how inverters/frequency drives work to slow/speed the motor by varying AC frequency, such as the ones in modern front load washing machines.

 

[swynx]

Yes it is a 88p. I'm sure you guys are correct about the voltage spike. I always use it with the engine running. I think ill contact viair see what they say

 

[swynx]

so i contacted viair, they said i have to have the truck running because, low voltage can create high amp draw.

however, they said that if i ship it to them, they will inspect it free of charge.

but... after thinking, i think iv always used it with the led light bar on so i can see while airing up in the dark. could this be my problem?

 

[RonD]

No, to the light bar, unless you are running it thru that 20amp fuse.

You would have at least a 95 amp alternator in a '94 4.0l.