Finally got an air compressor, need some help.

Breakers are not rated for starting load, and should not be used to start and stop a compressor. You will either ruin the breaker, or weld the contacts shut on it, and cause the compressor to not shut off, or not run.
You should install a correctly sized manual starter that has provisions for overloads, and get overloads for 125% of the nameplate rating for your 7.5hp motor. If you don't put overloads ahead of your compressor motor, and you ever have trouble with the compressor failing, it will cost you a new motor also! Without overload protection the motor will go up in smoke if the compressor fails.

 

Black pipe or aluminum. A couple of manufacturer's have the aluminum tubing just for this purpose, and guess what? No rust etc. when you get water. It will be a bit more expensive, but I've plumbed air with it on a few commercial jobs and it is top shelf.

 

DO NOT use PVC!!!!!!
People think that because it is rated for a certain PSI of LIQUID that it should be ok for the same PSI of AIR. Not so. The difference is you can't compress a liquid. You break a PVC pipe with 100 PSI of liquid, the liquid just sprays out. Break the same PVC pipe with 100PSI of COMPRESSED AIR and the air expands as it escapes. That expanding air will carry PVC shrapnel that can kill you.

 

The Aluminum piping does not rust sure but what happens when water and aluminum come into contact for long periods? I have used a few of the newer aluminum piping systems in industrial plants as well, but for a worry free system that you can add onto easily and modify easily you cant beat copper. Any part you need can be had by the nearest hardware store for a fraction of the cost of the aluminum systems when it comes to the home garage system. And will outlast it tenfold.

 

X2...I run a large volumn pressure regulator right off the tank set to 100#..Smaller volumn regulators at each drop set to whatever I desire [up to the pre-set 100#] to do whatever needed..All regulators have water traps..Since I have more than enough volumn I don't feel the need to run the compressor all the way to 175# so I have the pressure switch set for 150# for less wear/tear/heat..And on a note: If you choose to use the push together plastic flexable line kits they do go together nice but be prepared to fight leaks for a while..

 

Those of you that flip the breaker off & on for a switch , take note. A friend had done this for years & one day his compressor motor would barely run. Because the unit was old, he called his friendly Snap-On dealer and had a new compressor delivered. Installed it himself & SOS, it would barely run. The problem was that one side of the 220v breaker was corroded from years of arcing when the breaker was thrown.

 

I know it sounds strange but this air compressor seriously doesn't have any kind of on/off switch at all. I too am shocked that you pay that much for something and you can't turn it on and off but whatever. It has a pressure switch to shut off at 175 psi but does not have any little lever or switch on it to shut it off when ever. It is single phase and looking at it today I believe I noticed where you can put a switch. I have to clue why I never noticed/realized it before but here are some pics. Right on the cover with the reset button is a metal tab with some plastic push in rivet things. Right behind that on the inside is a metal plate. If I am correct this is for mounting an on/off switch right? If so anyone know exactly what I should buy and how to wire it? Thanks.

Here's the cover, kind of hard to see but the black spots are push in rivets that hold on a metal plate that can be removed.
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This is the cover off. The metal plate sits right behind it where I believe you mount the switch.

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Sorry, but this is just bad info. After 35 years as an electrician, I can tell you that not only are most breakers NOT switch rated, even those that are wont hold up long to the starting in rush current of a 7.5hp compressor motor. Starting amps on motors can be 500-600% of the nameplate rating, and breakers (even switch rated) will not stand up to motor loads starting.

 

These large commercial compressors are not intended to be "turned on/off" by a manual switch. You feed them power through a circuit breaker in a panel (or a fused circuit with a local wall-mounted disconnect switch) and the regulator takes it from there. Why would you need to shut it off manually, anyway?

 

That's a decent Eaton starter, and it has overload protection built in, so all you need is a on/off switch across the holding circuit for the coil to start it. The wire marked "42" can be pulled from the terminal and a 2nd wire put on that terminal. Then the two can be attached to a simple toggle switch on the side of the box to start-stop the motor starter. If you wire it this way the pressure switch will still be in line, as will all the safeties, and it will cycle as designed, but shut down when you turn the toggle off, whether it's calling for air or not.
You should hire a qualified electrician to connect it up, if you're uncertain of how to wire it, or don't have the background to do so.

 

Check out this website. I have been in his shop and it is economical and works well. http://www.1969supersport.com/index.html

 

You are absolutely correct sir. And is refreshing to know there are others that give good info on this subject as I argue with "electricians" on a weekly basis on this exact subject. Also voodoo twin gave some good info as well siting the pressure switch in conjunction with a fused disconnect is the way they are designed to operate. You can however install an on off "interrupter" switch into the control switch but if you do you have to remember to shut the unit off after it has unloaded and stopped on its own preferably, also note that during a service you will still have live power at the contractor and is dangerous.


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i did them same and the rubber hose broke, the compressor full of air had enough force to launch the compressor until it ran out of electrical cord, it is bolted down now (loose)

 

Shit did this guy read my post #20 or anybody else think I covered the wiring part and if you have been working on cars you will want all the air you can get you know all air tools have a throttle.

 

I have been corrected.
I apologize for posting incorrect information. Deleted my thread so no one gets the wrong idea.

Thanks guys for clearing that up. I got my info from a electrician that has 30 years experience.
Guess I need to go to the source for recommendations...

 

Hey 1970Malibu, congrats on your new compressor. You didn't state what the CFM rating is but being a 2 stage, should be big enough for most jobs around your shop, unless you plan to run a sand blaster unit which uses up a whole lot of air. Good suggestions coming your way and I would like to add some if I may.
1. Go to tptools.com and download their recommended set-up for plumbing your air supply lines in your shop. They have been in the business for a long time and are highly recommended.
2. DO NOT use PVC pipe as there have been numerous accidents with it in compressed air service. Fact is, OSHA has banned PVC use in compressed air service for obvious reasons. Black pipe is prolly the best, as you can lay out your air lines to utilize full 20 Ft joints of the pipe to save on making a lot of cuts. Home Depot and maybe Lowes will cut and thread some of your off size pieces for you if you buy the pipe from them.
3. Leaving the compressor on the pallet will not harm a thing, and will help with harmonics vibrations induced by the reciprocating motion.
4. Using a high pressure flexible hose between the tank and your distribution lines is also good practice.
5. Pick a location in your shop for the machine as it will be noisy. An outside shed is good for noise control. Keep in mind, that in high humidity areas of the world, it is going to be sucking in a lot of that and creating moisture in the air it makes. The heat of compression itself also creates moisture in the air so you will need to set the machine where you can drain water regularly or invest in a good moisture dump valve. You will also need a good moisture trap and filter assy to protect your pneumatic tools.
6. Last but not least, keep in mind, when you are plumbing your system, that any ONE small sized fitting you install in the system line will compromise the available CFM downstream from that point.
Hope this helps you,,,my wife tells me I tend to be long winded so please excuse the long winded post.
Don't hesitate to ask if you need anything else.

 

One more question. All my wiring is 6 gauge, which they say you need at least 8 for the compressor so I am good there but was wondering about my breakers. The garage is detached so I have a panel in the garage and the house. It says I need an 80 amp breaker because the initial start up is almost 3 times the running amperage which is 34 according to my spec sheet I got with it. So I need an 80 amp breaker in the garage but what should I put for the garage one on the panel in the house? Should I put another 80 or go 100? Right now the one in the house for the garage is 50 amp breaker.

 

STOP!!! YOU NEED AN ELECTRICAN. The breaker is for the protection of the wire associated with the maximum end load. You can't just change the breaker if the wire from the house to the garage is only rated for 50 amps. If you have a fire, I doubt the insurance will cover your loss. Maybe the 7.5 hp is a little overkill for a home shop with only you working, you should have explored the electrical issue before purchase.

 

Great, nothing ever goes right for me. First I ask on here what size compressor I should get and everyone tells me the biggest and nicest one you can afford, so I do. Now I'm being told I bought too big of a compressor. I can assure everyone I am NOT going to be doing any of the electrical work myself now so don't worry. I'll have an electrician come out and check it all out and see how much it's going to cost, but if it costs way too much I'm not sure what I'll do. I'm young and can't afford lots of things so I might just get out of the hobby all together. I appreciate everyone's input and responses and thank everyone for their help.

 

Don't get discouraged. You will love the bigger compressor. Just make sure that you get good advice on the electrical installation, whether you have an electrian do it for you or he advises you on what to do (let him inspect it later after your work before you energize it). Paying a little more for some expert opinions/advice will save you a lot of money in the long run.

 

1970Malibu,

Don't get discouraged man. Like anywhere else the moment you ask a question you will get 400 experts with different opinions all telling you the last guys opinion was total bullcrap. I am sure you will love the compressor as one that size should be able to do anything you require of it. Bite the bullet and pay for the electrician to hook it up and enjoy many years of worry free compressed air. Look at some pro body or mechanical shops and see how they arrange their water drains to avoid getting water in the lines and then adapt something to fit your shop size. Have fun.

 

"Eastwood" has a great alum. pipeing system and I thnk it under $200.00.

 

I wouldn't get too worried just yet. no.6 is plenty big its just a matter of how much other stuff you have in the garage with it. Definitely let the electrician check it out and I would get at least three quotes before you make a decision.

 

What Post # 17 said,...and, add a good water separator on the out let side of the tank. Especially if you're going to do any painting.

4TTRUK

 

I have my compressor lines T'd off twice , so I can plug in numerous hoses , I put a drier in my Spray line , And my 1st line is for my 3/4 and 1 inch impacts, and sandblaster . I have a 1 inch ball valve at the tank, I run it @ 175, it is needed when two of us are using long boards , (150 is plenty for one person) You can tighten or loosen the nut on your pressure switch to adjust pressure . I put it on a 40 amp breaker , and I shut off the ball valve at night and have never shut off the power in five years . It has only turned on at night when I forgot to unplug a leaking tool, and forgot to turn off the air . I just got in the habit of unplugging tools , but, being human ,I forget ... Mine is all black pipe . and DO NOT cheap out on your hoses , Flexzilla is great ,