[Kenpilot]

I built an air cannon last year and it was a hit! Scared the Sh*t out of everyone that walked by. Only problem is, my compressor over heated and blew the Circuit Breaker half way thru the big night. Its a 3HP/10 Gallon Compressor connected to the Air cannon which is a 7 gallon resevoir tank. Compressor fills to 115 PSI and refills at like 90 PSI I believe. The Air Cannon was set at like 30 PSI when fired. It was on a timed motion sensor so it only fired at the minimum every 2 minutes. I know Air Cannons are air hogs but any ideas on how to fix this problem? Bigger Compressor? Another resevoir tank between the compressor and Air Cannon?

 

[bfjou812]

Check the amps on the motor of the compressor and make sure the circuit breaker is rated to handle the load, that would be the first thing I'd check. Did it actually overheat or just trip the breaker? If it did overheat ,you would need to put it in an area where it will get good airflow to keep it cool.

 

[Kenpilot]

Check the amps on the motor of the compressor and make sure the circuit breaker is rated to handle the load, that would be the first thing I'd check. Did it actually overheat or just trip the breaker? If it did overheat ,you would need to put it in an area where it will get good airflow to keep it cool.

Im pretty sure the Circuit is rated to handle the load, it did fine for half the night. I think it might have been just overheated. I had in enclosed in a "sound suppressing 3 sided box" that I made for it to cut down the noise. I left some room i it for airflow but maybe not enough. Guess I'll try it again but this time with a couple fans blowing across it. Maybe that will help ? Im just worried because I plan on building another pneumatic prop or 2. Maybe I just need to put an extra resevoir tank at each prop

 

[bfjou812]

I think you answered your own question with the cooling issue. If the compressor didn't have enough air to cool it it will overheat, adding extra reservoir tanks will increase storage, but also increase run time to refill them. It could be as simple as turning the compressor so the side with the fan on it is facing the opening in the enclosure so it brings fresh air coming in. Also make sure the enclosure is large enough to allow the air to circulate out of it. Hope this helps.

 

[Kenpilot]

I think you answered your own question with the cooling issue. If the compressor didn't have enough air to cool it it will overheat, adding extra reservoir tanks will increase storage, but also increase run time to refill them. It could be as simple as turning the compressor so the side with the fan on it is facing the opening in the enclosure so it brings fresh air coming in. Also make sure the enclosure is large enough to allow the air to circulate out of it. Hope this helps.

Well I thought I built it big enough for the air to circulate but guess not. And I didnt think about it having to replenish the resevoirs too, so thanks for the heads up. I wish the tank filled to more then a measly 115 PSI. It kicks on when it drops to 90. Im thinking of just splurging for a Husky 30 Gallon tank thats rated to like 155 PSI. That way I have more air AND it won't kick on as much if it has to drop from 155 to lets say 90 before kicking on again. Thoughts?

 

[bfjou812]

Bigger is better!! LOL!! What you need to look at really is volume of air being used. I have a 5 hp, 60 gallon upright compressor and it puts out about 15 scfm @ 90 psi. I have it set @ 110 psi so it is a little less effiecent but I use mine mostloy for air tools. It ia a single phase 220 volt unit and is definetly not portable. You could go with something like that and just run air hose or tubing to the desired prop. A 10 gallon tank seems sort of small to me. just remember that size of tubing ,air hose , cylinders all start to add up fast. What you probably should do is try to add up all of the devices that will be used and size accordingly. Remember pressure doesn't necessarily equal volume. Hope this helps.

 

[Kenpilot]

Bigger is better!! LOL!! What you need to look at really is volume of air being used. I have a 5 hp, 60 gallon upright compressor and it puts out about 15 scfm @ 90 psi. I have it set @ 110 psi so it is a little less effiecent but I use mine mostloy for air tools. It ia a single phase 220 volt unit and is definetly not portable. You could go with something like that and just run air hose or tubing to the desired prop. A 10 gallon tank seems sort of small to me. just remember that size of tubing ,air hose , cylinders all start to add up fast. What you probably should do is try to add up all of the devices that will be used and size accordingly. Remember pressure doesn't necessarily equal volume. Hope this helps.

LOL this is true I definitely want the 30 Gallon tank but hard to justify the $400 when I have a perfectly good compressor in the garage ya know? But if I'm going to spend X amount of $ on resevoir tanks and hoses and stuff that could very well be spent towards the 30 Gallon. So confused what to do!! LOL And I do appreciate all your help Thank you

 

[GrimShady]

Rewire your compressor to run on 220V. That should help the heat issue. Put a fan to circulate the air into your noise suppression box.

Use a different style of air cannon like this one that doesn't use as much air.
Air Cannon Pneumatic

 

[brushe]

Did you have it on a drop cord? I know some times if I have to pull to much cord, after a while it will throw the breaker. Not just my compressor, but my table saw also.

 

[Kenpilot]

Did you have it on a drop cord? I know some times if I have to pull to much cord, after a while it will throw the breaker. Not just my compressor, but my table saw also.

Nope, was plugged straight in to an outlet

 

[Kenpilot]

Rewire your compressor to run on 220V. That should help the heat issue. Put a fan to circulate the air into your noise suppression box.

Use a different style of air cannon like this one that doesn't use as much air.
Air Cannon Pneumatic

I'll probably just try to put a fan or two in the suppression box to help circulate the air better. Hopefully that will do the trick.

 

[bradbaum]

Has anybody ever tried hooking multiple air compressors to the same plumbing to share the load?

Seems to me this would work, but I have never heard of anybody trying it.

 

[SkeletalRemains]

Air compressor

The problem here Ken is probably the duty cycle on your compressor. 10 gallon is pretty small, and the duty cycle is probably somewhere in the neighborhood of 30%. Basically that means it is capable of running for 3 minutes out of 10. If you use it more than 3 minutes every 10, it will start to heat up and degrade. Eventually it will stop and possibly blow a breaker. Bigger compressors that may be rated at 80-100% duty cycle can actually stay running much longer without overheating and should cause no problem. Sounds like the compressor runs fine under normal circumstances. I would get a bigger compressor with a higher duty cycle.

As far as adding an additional compressor to the mix on the same air line, it shouldn't cause any issue. I have done that before and ran a lot of stuff off of it. Basically what that does is evenly split the load between compressors. The one real issue that can cause problems is you put two compressors on the same line where one is rated at 120psi and the other at 175psi. The smaller compressor isn't built to withstand 175psi, so you must use two compressors with very similar ratings. I would not rely on the diaphragm regulator, instead use a check valve (one-way) on EVERY compressor connected to a multi-compressor air bus.

 

[Kenpilot]

The problem here Ken is probably the duty cycle on your compressor. 10 gallon is pretty small, and the duty cycle is probably somewhere in the neighborhood of 30%. Basically that means it is capable of running for 3 minutes out of 10. If you use it more than 3 minutes every 10, it will start to heat up and degrade. Eventually it will stop and possibly blow a breaker. Bigger compressors that may be rated at 80-100% duty cycle can actually stay running much longer without overheating and should cause no problem. Sounds like the compressor runs fine under normal circumstances. I would get a bigger compressor with a higher duty cycle.

As far as adding an additional compressor to the mix on the same air line, it shouldn't cause any issue. I have done that before and ran a lot of stuff off of it. Basically what that does is evenly split the load between compressors. The one real issue that can cause problems is you put two compressors on the same line where one is rated at 120psi and the other at 175psi. The smaller compressor isn't built to withstand 175psi, so you must use two compressors with very similar ratings. I would not rely on the diaphragm regulator, instead use a check valve (one-way) on EVERY compressor connected to a multi-compressor air bus.

Ok thanks for the advice! I am really starting to lean towards shelling out the $400 for the new compressor and just being done with it and setting my mind at ease. Thanks again!

 

[Mr Unpleasant]

If you do buy a new compressor, I reccommend it be "oil" cooled, they don't overheat nearly as quick as the air cooled models if at all.

 

[SkeletalRemains]

If you do buy a new compressor, I reccommend it be "oil" cooled, they don't overheat nearly as quick as the air cooled models if at all.

Yeah the oiled compressors are always better typically, I haven't seen any oil-type compressors that WEREN'T fairly heavy duty with a high duty cycle.

 

[Screaming Demons]

Another compressor is the way to go. Adding extra tanks doesn't really deal with the volume problem mentioned by bfjou812 at all. More tanks would work for a little while, until those tanks start to run down, and then you're right back where you were before. You need a compressor that puts out more air (CFM), not necessarily more psi.

You should definitely look into either a cannon reqiuring less air, or see what the minimum your existing cannon can get by with. The Punkin Chunkers discovered that higher psi didn't really throw the pumpkins any farther, and tended to make a mess.

 

[SkeletalRemains]

Glad you mentioned that

I just realized that I didn't even mention CFM in my previous post Demons, but you are exactly right. A lot of the typical compressors out there ($200 at home center) will only push about 5 CFM at 90psi. Usually you will get a higher CFM with a bigger compressor, not that I haven't seen an itty bitty compressor put out 20CFM before (Ingersoll Rand is very sexy as compressors go!) Of course you'll drop a few grand on one of those.

Just to reiterate Demons point that finding a higher CFM rating on a compressor is better than buying more tank than you need (or adding tank)

If you really want to get nuts, go for a two-stage compressor - it'll cost you a lot but you'll NEVER run out of air unless you're running Halloween Horror Nights for Universal...

 

[ibjeepin]

The problem here Ken is probably the duty cycle on your compressor. 10 gallon is pretty small, and the duty cycle is probably somewhere in the neighborhood of 30%. Basically that means it is capable of running for 3 minutes out of 10. If you use it more than 3 minutes every 10, it will start to heat up and degrade. Eventually it will stop and possibly blow a breaker. Bigger compressors that may be rated at 80-100% duty cycle can actually stay running much longer without overheating and should cause no problem. Sounds like the compressor runs fine under normal circumstances. I would get a bigger compressor with a higher duty cycle.

As far as adding an additional compressor to the mix on the same air line, it shouldn't cause any issue. I have done that before and ran a lot of stuff off of it. Basically what that does is evenly split the load between compressors. The one real issue that can cause problems is you put two compressors on the same line where one is rated at 120psi and the other at 175psi. The smaller compressor isn't built to withstand 175psi, so you must use two compressors with very similar ratings. I would not rely on the diaphragm regulator, instead use a check valve (one-way) on EVERY compressor connected to a multi-compressor air bus.

I agree with SR on this one and would add that type of compressor does make a difference. Whether its a noisy diaphragm compressor, whether its one two or four cylinders, or whether its a standard piston compressor, or a screw type all make a difference to the duty cycle and the price.

 

[Kenpilot]

Thanks again guys for all your help and advice. Here's what I have come up with to compare what I have with what I am looking at possibly getting. Let me know if you think its going to make any differece:
I have now:
- Central Pneumatic-
10 Gallon, 3 HP, Air delivery: 5.6 CFM @ 90 PSI; 7.2 CFM @ 40 PSI
115 PSI, Kicks back on at 85 PSI

I'm looking at getting:
-Husky/(Campbell Hausfeld )- $399 . Vertical and on wheels thus portable. Excellent reviews. 120 Volt but can be coverted to 240 Volt.
30 Gallon, 2 HP, Air delivery: 5.5 SCFM @ 90 PSI; 6.5 SCFM @ 40 PSI
135 PSI
Husky 2.0 Running HP 30 Gallon Vertical Compressor - VT6315 at The Home Depot

OR

- Kobalt - On Sale for $438. Vertical NON portable. No reviews, not even on the Lowes Website. 208-220 Volt ( my home is 120 Volt) So can I even use this?
60 Gallon, 3.7HP, Air Delivery : 11.5 SCFM @ 90 PSI; 13.4 SCFM @ 40 PSI
155 PSI

-

What exactly is the difference between "CFM" and "SCFM"?
Thoughts?