View Full Version :

Air compressors

05-12-2009, 09:53 PM
I have the 40D and use a Sanborn 5hp with 20 gal tank that puts out 5.7 @90. I am thinking of getting a bigger one. Probably vertical, still trying to stay with 110 cuz in order to go 220, I have to run another circuit cuz my existing one is tied up when I use my 40. So, just wondering what ya'll use for a compressor. I occasionally run a high speed cutter and misc air tools, but nothing for very long. No painting and no D.A. I'm just a hobbiest so I can stand there and whistle while waiting for it to catch up. That's what I usually do... I know: bite the bullet and run the circuit, right?
Anyway, what ya'll usin?

05-12-2009, 10:18 PM

One of our testing stations has a 30gallon 110v and it is fine. Depending on the cost of 220v, it may be or may not be worth it. However, remember the welders and cutters perform much better on 220v.


05-13-2009, 12:00 AM
Probably at least 9 to 10 cfm min is where you want to be. 220 is really the way to go and so far for me I have survived on a single 220 circuit of 50 amps. both my 200p and a 5hp compressor run on this circuit and it has not kicked off once yet.

depending on where your box is, if it's in the same garage you might simply drop another 220 line right at the box for a plug. It's really simple to do and gives you great flexibility.

Also, depending on your needs, I always had an issue with higher pressure taking too much time to recharge so went with a two stage which is really nice. As a hobbyist I think the higher pressure and 10 cfm is better than a single stage and 15 cfm for me.

05-13-2009, 01:42 AM
I would recommend you drop the aditional line for the 240 volt compressor.
I have a 3 hp compressor, if I wire it for 120 volt the run amps are 16, and the start amps can be as much as 30 amp. If I wire it for 240 volt the run amps are 8, and the start amps can be as much as 15 amp. On the 120 volt hook up you may see lights flickering, and problems with electronic equipment when the compressor starts.

If you have a 5 hp compressor:
120 volt; run amps 27, start amps 50
240 volt; run amps 13, start amps 25

These numbers will vary depending on the efficency of your equipment. But I think you get the idea.

I would also recommend a two stage compressor as previously mentioned.

05-14-2009, 09:55 PM
I looked into this a little more and found the following;
Most modern air compressors have a unloader valve built into the compressor. This unloader valve releaves the air pressure from the compressor head when the compressor reaches it's shut off point. When the compressor starts it does not have the tamk pressure pushing on it, so the starting anps are reduced by about 70%

If you have a 5 hp compressor:
120 volt; run amps 27, start amps 42
240 volt; run amps 13, start amps 20

Sory for any confusion I may have caused

05-15-2009, 08:32 AM
Thanks guys for the information.
I am gonna cave in and drop another 220v circuit. In fact, I found the compressor I am gonna go with. At my local Menards, I found a Sanborn that puts out 11.5 at 90. That should cut down on my whistling time! 60 gallon tank. Oil lubricated. I think it tops out at 155 or 160. Gonna fit my needs.
I'm gonna get it next week when my very large young friend gets back in town. They want $40 to deliver it and I would rather spend the $40 on the extended warranty so when Brian gets back, we'll go pick it up. It comes with 2 yr warranty and the extended goes another two years.
Thanks again and when I get it all set up, I will send pics.

05-21-2009, 07:26 AM
I have a 5hp, 80 gal single stage (220v 17.5 cfm @90psi). I've found that I can fill the tank, unplug the compressor and plug in the 40D and cut quite a bit with no problems. The 80 gal tanks lasts a good while. You shouldn't have a problem. An extra 220 drop would be much more convenient tho.

05-21-2009, 09:13 AM
Thanks for all the help! I quit whining and put another 220v circuit in. Bought a Sanborn 5hp, 60 gal tank. Puts out 10.5 at 90.
That should cut down on my whistling time! Wired it and plumbed it. Now just need to get it anchored and I will be off and running. Well, not exactly running but you know what I mean.
Now I can create my silly little things faster...

05-21-2009, 06:17 PM
You won't regret it at all! There's nothing better than having the air capacity you need for the whole shop, I've always said if I lost everything the first item to buy would be a good compressor! Good choice, just maintain it and you'll get years of good life out of it, i.e. check the drain or get an auto drain device.