Air Bag Compressor Replacement Sizing Question

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Skipper

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Joined
Mar 15, 2021
Posts
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Location
The Woodlands, Texas 77381
The 12V Viair Compressor died! It only filled 4 bags on single air supply circuit. The electric circuit was fused at 15 amp. Bags normally pumped to 40-50 psi. Now the problem. What size replacement Viair to buy? Looking at the 92C as everything else exceeds 15 amps. The bad pump does not show it's size. The 92C pumps to 120 psi which seems sufficient for a single air supply circuit. Need your feedback.
 
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My Viair 400P runs just fine when connected to my vehicle's battery, and I've been using it for years to pump up tires on my Jeep and I've occasionally topped off my 22.5" RV tires, but that's very slow. It's not designed for the typical 12V outlets. Are these air bags in a suspension? How many are there total? Have you tried connecting direct to the battery? Which Viair model is it?

Once my Viair 400P seemed to die (reversed connection), and I almost got rid of it, but decided to try one more time and it's been running fine ever since (evidently some cockpit trouble).

The 92C is a light duty unit, and their web site says:

VIAIR’s 90 Series compressors offer a light duty solution for smaller air requirements and are designed to fill no larger than a 1.0 gallon air tank.

It may do 120 psi, but extremely slowly (much less volume, which is most important) and may not do what you want.
 
I think you are being overly cautious with your 15A limit. Thats only about 150W in a 12V system. Even the cigarette lighter is usually good for twice that. I've used my ViAir to fill jeep tires on a regular basis. I suspect it draws more like 250-300W and a single battery will easily support it long enough to top off all four tires.

Ernie
 
I think you are being overly cautious with your 15A limit. Thats only about 150W in a 12V system. Even the cigarette lighter is usually good for twice that.
He stated the circuit used was fused at 15A, which is a 12v common limit for 12v utility outlets. He would be better off installing a heavy duty 12v outlet directly off the batteries, with 10 or 12 gauge wire to get 20-30A. 15A isn't much for a compressor. Or use clip leads to connect direct to the battery terminals.

The 12V Viair Compressor died! It only filled 4 bags on single air supply circuit. The electric circuit was fused at 15 amp.
I suspect his existing outlet is undersized in wire gauge as well as 15A fused, causing a severe voltage drop until the fuse finally blows (or the wire melts). A 12v motor/compressor will overheat badly when run at low voltage, and that's likely what destroyed his Viair.

A smaller (lower power) compressor can still reach high psi, but it has to reduce the air volume (CFM - cubic-ft-per-minute) substantially to do that. That means slower filling, which in turn cause longer compressor runtimes and greater chance of overheating. A larger (more amps) power source is a better solution than a smaller compressor.
 
Viair list specs for my 400P as:

– 12-Volt / 24-Volt​
– Permanent Magnetic Motor​
– Duty Cycle: 33% @ 100 PSI​
– Max. Working Pressure: 150 PSI​
– Max. 12V Amp Draw: 30 Amps​
– Max. 24V Amp Draw: 15 Amps​
 
Viair list specs for my 400P as:

– 12-Volt / 24-Volt​
– Permanent Magnetic Motor​
– Duty Cycle: 33% @ 100 PSI​
– Max. Working Pressure: 150 PSI​
– Max. 12V Amp Draw: 30 Amps​
– Max. 24V Amp Draw: 15 Amps​
Larry, I just received a viair 400P and no where in the documentation does it mention 12V operation. in fact it emphatically states it is 24volts only. I am about to return it. where did you find out that 12volt operation is possible? Do you just operate on 12 volts and have had no bad things happen?

Kevin
 
Larry, I just received a viair 400P and no where in the documentation does it mention 12V operation. in fact it emphatically states it is 24volts only. I am about to return it. where did you find out that 12volt operation is possible? Do you just operate on 12 volts and have had no bad things happen?

Kevin
I just looked at the data plate on my 400P and it says it's a 400P-A, 12V DC, part no. 40045 (I've had it for several years), and max 145 psi.

On the Viair web site is shows two versions, one for 12V and one for 24V, with the 12V part being 40043 and the 24V part being 40050, both running 150 psi. Guess they've updated the unit.

Look at this on Viair's web site:

I presume the -A on my model no. means automatic:
 
Thanks Larry. Looks like there are about 4 different variants of the 400 model. including 12 and 24 volt models and different flow rates. 12 volt version was ordered yesterday and arrived today. I cant believe how quiet it is!


Kevin
 
Thanks Larry. Looks like there are about 4 different variants of the 400 model. including 12 and 24 volt models and different flow rates. 12 volt version was ordered yesterday and arrived today. I cant believe how quiet it is!


Kevin
I should have waited to order the replacement unit. The seller wants to charge me To return the original unit. I already paid, not paying again. Don't follow my lead make sure you order the right compressor the first time.


kevin
 
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