Another compressor thread 10+ CFM no 40/50amp circuit

[cccoltsicehockey]

So I know another air compressor thread. Just what everyone wants to see. I have searched and possibly read over 50 threads on here at this point. I am well aware the standard like is put in a 5hp/60gal or just forget about it.

I already have a 240v 20amp and 240v 30a circuit in the closet where I want to put the compressor. The 30amp is really for the hot water heater but I could wire up a smart controller and a remote switch to cut power to the hot water heater when I want to use the compressor.

I am trying to not have to run a separate circuit beyond what is already there unless it really does turn out to make the most sense.

I have found two compressors so far. One provides a bit more overhead which would be nice but the reviews are not what I call great. The other from CAT does not seem to have a ton of reviews. I imagine that is because of the cost per output which I admit is not the greatest. It mainly meets my noise and power use requirements but that does come at a cost.

The two are the Eastwood 30/60 Scroll which does 12.7CFM and the California Air Tools 60040CAD which actually runs dual pumps to get you to 10.6CFM.

Eastwood Elite QST 30/60

Eastwood Elite QST 30/60 Scroll Air Compressor with Automatic Drain System

Combining whisper-quiet operation with high airflow and 100% duty cycle, the Eastwood Elite QST30/60 compressor delivers unmatched performance without unwanted noise.

www.eastwood.com

California Air Tools 60040CAD

California Air Tools 60040CAD 4 HP 60 Gal 125 Max PSI Single-Stage Stationary Electric (230 Volt) Reciprocating Air Compressor with Auto Drain | Ferguson Home

Save on the California Air Tools 60040CAD from Ferguson Home. Low Prices + Fast & Free Shipping on Most Orders. Find reviews, expert advice, manuals, specs & more.

www.aircompressorsdirect.com

The power in my garage is run weirdly in my mind. I already have 400amp at the house so we are running a 100amp sub panel with a 125 breaker off each of those house panels to feed the garage. Part of the reason of not wanting a 40/50amp compressor is I rarely will need 10-12CFM+ but would rather have it from whatever I buy is that I am worried about the load across those two panels. One has 3 mini spits on it and a potential 2 outlets for a welder in two areas of the garage. The other panel has 1 mini split, my lifts, water heater, and a potential future EV charger. The EV charger is really just a future proof though at this point as I have no plan to actually buy one.

My main needs are the basics but I also have inherited a few grinders and cut off wheels that I would like to be able to use and they seem to all require 9+ cfm. I also would like to get a small blast cabinet someday possibly but the Eastwood lower pressure 7CFM would likely be the most I would get. It is not even definite that I would ever follow through with the blast cabinet idea either.

I could technically just run the additional wire now though to support something larger. Noise though is also a concern so I would like to stay with something 75dba or below.

Looking to hear some suggestions and also if anyone has any experience with this particular cat model.

 

[sherlocktk]

It says in the spec 230v 14 amps, you should be good on your 240v 20 amp circuit. My 5hp harbor freight compressor pulls around 22 amps @240v. California Air Tools power consumption seems appropriate for what it is.

 

[vanapplebomb]

You can run a 3HP 220V compressor on a 20 amp breaker, or 5hp on a 30 amp.

I have mixed feelings about the compressor choice though. I have seen a number of short live Eastwood scroll compressors. Good concept, very average execution. As for the duty cycle of the California Air Tools compressor, I think their claimed 70/30 is optimistic. Will it do it? Yes. Is it happy about it? Well… it gets pretty toasty. Just something to consider. That’s all.

 

[cccoltsicehockey]

Interesting. I did not know about being able to run a 3hp on a 20amp circuit. I see Puma makes one that fits that bill and does 11cfm and some reviews claim is only 75dba which I find unlikely though seeing the pump design.

Now looking like either one of these might suit my needs and save the wallet a bit.

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

Not sure honestly is I prefer the 2 stage or the slightly higher CFM at that price point.

 

[Cruzan80]

Depending on brand, some "5HP" motors are actually labelled SPL, and pull 15A.

 

[Chris_Hamilton]

Interesting. I did not know about being able to run a 3hp on a 20amp circuit. I see Puma makes one that fits that bill and does 11cfm and some reviews claim is only 75dba which I find unlikely though seeing the pump design.

Now looking like either one of these might suit my needs and save the wallet a bit.

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

Not sure honestly is I prefer the 2 stage or the slightly higher CFM at that price point.

Bigger is always better with a compressor. Both in CFM and storage. You'll never regret going bigger. Or spending a bit more than you budgeted for. A 30 amp circuit could power a true 5hp 2 stage compressor with a mag starter.

 

[GeoBruin]

Interesting. I did not know about being able to run a 3hp on a 20amp circuit. I see Puma makes one that fits that bill and does 11cfm and some reviews claim is only 75dba which I find unlikely though seeing the pump design.

Now looking like either one of these might suit my needs and save the wallet a bit.

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

FergusonHome Well Pumps

Shop our selection of Well Pumps at Ferguson Home. Large selection of Well Pumps from top manufacturers

www.aircompressorsdirect.com

Not sure honestly is I prefer the 2 stage or the slightly higher CFM at that price point.

For your purposes, I would ignore the horsepower rating, and focus on the actual rated current draw. That said, the 3hp (advertised) range is going to be the sweet spot for hitting 10ish cfm but using a 20 amp breaker. I've always like the look of that puma when it had been discussed before. The Eastwood and the CAT are both expensive for the output you get because they're unique/specialized, but they are probably your quietest options. I don't think you will find any other options in your price range that will be at or below 75 dba.

Depending on your power setup, you could consider 2 separate CAT 5cfm models in your preferred tank size/configuration run in parallel (when needed) but that introduces some other logistical hoops. It would however cost half what that duplex CAT costs.

Good luck!

 

[Pontiac787]

Agree with the above posts. Spend a little time researching motor specs. 50 amps will run a lot more than a 10 cfm pump. You’ll be fine with the 30 amp circuit, possibly the 20 as well.

 

[vanapplebomb]

Bigger is definitely better for those who use air power. I got a 5hp two stage, and while it works, really wish I sprung for the 7.5hp. Its right on the edge of some of my tools demands.

 

[micromind]

The code rules for motors , wire size and breakers is different than normal.

For example, a basic 5HP 230 volt single phase motor can use #10 (not Romex though) and a max 70 amp breaker.

#10 Romex can only handle 3HP @ 230 volts and a max 45 amp breaker. Same with #12.

Just for fun, a 1HP 115 volt single phase motor can be fed with #14 (including Romex) and a max 40 amp breaker.

Motors, welders and HVAC are about the only things in the code that allow larger than normal breakers.

 

[cccoltsicehockey]

Agree with the above posts. Spend a little time researching motor specs. 50 amps will run a lot more than a 10 cfm pump. You’ll be fine with the 30 amp circuit, possibly the 20 as well.

Bigger is definitely better for those who use air power. I got a 5hp two stage, and while it works, really wish I sprung for the 7.5hp. Its right on the edge of some of my tools demands.

The code rules for motors , wire size and breakers is different than normal.

For example, a basic 5HP 230 volt single phase motor can use #10 (not Romex though) and a max 70 amp breaker.

#10 Romex can only handle 3HP @ 230 volts and a max 45 amp breaker. Same with #12.

Just for fun, a 1HP 115 volt single phase motor can be fed with #14 (including Romex) and a max 40 amp breaker.

Motors, welders and HVAC are about the only things in the code that allow larger than normal breakers.

Appreciate all the advice.

Agree bigger is always better you don't want to regret and buy again. I do this with pretty much everything. That said based on my current use of air I feel like I already might be going bigger than what I will ever use. So a 30amp circuit which seems can get me depending on the model up to about 13-14cfm depending on how much I want to spend on a compressor should more than meet my needs.

I see looking at the details that these Puma 3HP that I thought might fit on my 20amp technically exceed the 80% rule by a whopping .6amps. What would be the risk of running that on a 20amp or should I 100% pull the 30amp to replace the existing 20amp?

 

[GeoBruin]

The advantage of the 30 amp circuit is it opens up a lot more options in terms of compressors because it puts you in the 5ish horsepower range which is a configuration that is much more popular than three horsepower models. That in turn means you will have more used options as well if you're willing to purchase used.

 

[cccoltsicehockey]

The advantage of the 30 amp circuit is it opens up a lot more options in terms of compressors because it puts you in the 5ish horsepower range which is a configuration that is much more popular than three horsepower models. That in turn means you will have more used options as well if you're willing to purchase used.

I think the problem is though that since this is a stick build and fully closed walls we are pulling romex. So if I am reading the above information correctly then I would need to go 8awg instead of 10awg and then a 40amp to be ablet to run the 5ish horsepower range. It is my understanding you can't pull THHN without conduit right?

 

[GeoBruin]

I think the problem is though that since this is a stick build and fully closed walls we are pulling romex. So if I am reading the above information correctly then I would need to go 8awg instead of 10awg and then a 40amp to be ablet to run the 5ish horsepower range. It is my understanding you can't pull THHN without conduit right?

I'm sorry, I can't advise you on the electrical aspect. I will throw out 10/2 mc cable with thnn as an idea, but that may not satisfy the requirement you mentioned and I'm sure others will advise one way or another.

 

[tak1313]

I'm not electrician, so take my post with a grain of salt, but this is my understanding of it all:

1. A 240v/30amp outlet needs 10awg, a 40amps need 8awg, which is also the required gauge for a 50amp outlet
a. In the US, there is no 40amp receptacle - there are 30amp and 50amp, which makes the 40amp moot, since both require/use 8awg.

2. Both compressors in the original post are easily run off the existing 240v/20amp receptacle.

3. A 5hp compressor can be run on a 240v/30amp circuit/outlet (but not 20amp).

4. THHN requires conduit regardless of whether it is exposed outside the wall or not

I have a 3hp Husky compressor (actually a rebadged CH), and it runs off a 240v/20amp circuit/outlet no problem.

 

[micromind]

Going 0.6 amps over the 80% rule will work just fine.

 

[GeoBruin]

THHN requires conduit regardless of whether it is exposed outside the wall or not

This is why I wondered if mc cable might do the trick. It sounds like installation is the challenge for new conduit, so OP might be able to pull mc cable the same way they would pull romex (albeit with some additional difficulty) but still use the 10 gauge thhn.

 

[tak1313]

This is why I wondered if mc cable might do the trick. It sounds like installation is the challenge for new conduit, so OP might be able to pull mc cable the same way they would pull romex (albeit with some additional difficulty) but still use the 10 gauge thhn.

MY UNDERSTANDING is MC (metal clad) cable serves the same purpose as THHN through conduit (steel/aluminum or PVC) and is much more 'user friendly' than running conduit then threading THHN through it. MC can be used in wall or outside wall (but not outdoors), and has to be used outside of walls (exposed) or conduit must be used (cannot run Romex exposed.

The only drawback I can think of is depending on how long of a run he wants to install, he may end up with a lot of leftover MC versus just buying exactly what's needed. Can you buy MC (in 10awg) by the foot? When I installed a timer for my water heater, I had to buy 25ft of MC but only used 5 feet - the other 20ft has been sitting in my basement for the past 15 years as I have found no other use for it. At the time, I couldn't find MC by the foot, and because of where/how I was mounting the timer versus the water heater, running conduit would have looked weird.

Another option is using those "raceways" sold at the big box stores that run along walls/baseboards/etc and run the THHN through that. Caveat being I don't know if those things are rated for 3 wires @ 10awg.

Edit: Looks like they are rated for 3@10awg

https://legrand.webdamdb.com/directdownload.php?ti=55652801&tok=YVseksUMGetzHLmj9wv1pQRR

 

[cccoltsicehockey]

MY UNDERSTANDING is MC (metal clad) cable serves the same purpose as THHN through conduit (steel/aluminum or PVC) and is much more 'user friendly' than running conduit then threading THHN through it. MC can be used in wall or outside wall (but not outdoors), and has to be used outside of walls (exposed) or conduit must be used (cannot run Romex exposed.

The only drawback I can think of is depending on how long of a run he wants to install, he may end up with a lot of leftover MC versus just buying exactly what's needed. Can you buy MC (in 10awg) by the foot? When I installed a timer for my water heater, I had to buy 25ft of MC but only used 5 feet - the other 20ft has been sitting in my basement for the past 15 years as I have found no other use for it. At the time, I couldn't find MC by the foot, and because of where/how I was mounting the timer versus the water heater, running conduit would have looked weird.

Another option is using those "raceways" sold at the big box stores that run along walls/baseboards/etc and run the THHN through that. Caveat being I don't know if those things are rated for 3 wires @ 10awg.

Edit: Looks like they are rated for 3@10awg

https://legrand.webdamdb.com/directdownload.php?ti=55652801&tok=YVseksUMGetzHLmj9wv1pQRR

Well made the decision yesterday. Just before drywall went up I pulled an additional circuit with 10/2 MC cable. Going to start with a 3HP Puma but at least I have options down the road now if I find it isn't enough. Thankfully a buddy had 60ft laying around I bought off him instead of having to buy 125ft since I only needed bout 47ft.

 

[GeoBruin]

Well made the decision yesterday. Just before drywall went up I pulled an additional circuit with 10/2 MC cable. Going to start with a 3HP Puma but at least I have options down the road now if I find it isn't enough. Thankfully a buddy had 60ft laying around I bought off him instead of having to buy 125ft since I only needed bout 47ft.

Take some pics of that puma when it's up and running.

 

[Citation]

OP,

If you are used to the sort of things you can run with a 120V compressor, I suspect you will find even a 3hp ~10cfm compressor to be a huge upgrade. In my brother's garage we setup a frankencompressor with an 80 gallon tank and a HF "3hp" 2 cylinder pump. Per the specs it's a 10 cfm system. It has no trouble running things like the 4" zip wheel almost continuously (we were never slowed down waiting for the compressor). The sort of hand tools I would be worried about are DA sanders. Those would likely require a pause from time to time. Also, a 3hp compressor can power a smaller blast cabinet but again you are likely to need to pause from time to time.

A few other things to think about.
1. An after cooler is a good idea if you are going to do painting or heavy sanding. You can make one out of an oil cooler for under $100. They help condense the water out of the air before it goes into the compressor tank. The result is dryer air to the tool and less water in the tank itself.

2. The air intakes are a source of a lot of compressor noise. If you look at the Eaton quiet compressors you will find that they are basically creating their own quiet box for the intakes
This annoying, pop up laden website shows the emax manual where it basically shows how they setup their intake mufflers. Lots of other options as well. I have a much simpler setup on my compressor, it does really help

Intake Noise Suppressor Installation Manual by Eaton Compressor

Here are the installation instructions for Intake Noise Suppressor in Whisper 100 compressors along with the parts list. You will start by

www.yumpu.com

 

[cccoltsicehockey]

OP,

If you are used to the sort of things you can run with a 120V compressor, I suspect you will find even a 3hp ~10cfm compressor to be a huge upgrade. In my brother's garage we setup a frankencompressor with an 80 gallon tank and a HF "3hp" 2 cylinder pump. Per the specs it's a 10 cfm system. It has no trouble running things like the 4" zip wheel almost continuously (we were never slowed down waiting for the compressor). The sort of hand tools I would be worried about are DA sanders. Those would likely require a pause from time to time. Also, a 3hp compressor can power a smaller blast cabinet but again you are likely to need to pause from time to time.

A few other things to think about.
1. An after cooler is a good idea if you are going to do painting or heavy sanding. You can make one out of an oil cooler for under $100. They help condense the water out of the air before it goes into the compressor tank. The result is dryer air to the tool and less water in the tank itself.

2. The air intakes are a source of a lot of compressor noise. If you look at the Eaton quiet compressors you will find that they are basically creating their own quiet box for the intakes
This annoying, pop up laden website shows the emax manual where it basically shows how they setup their intake mufflers. Lots of other options as well. I have a much simpler setup on my compressor, it does really help

Intake Noise Suppressor Installation Manual by Eaton Compressor

Here are the installation instructions for Intake Noise Suppressor in Whisper 100 compressors along with the parts list. You will start by

www.yumpu.com

Interesting ideas on how to make it quieter. The intake box really does show you just about everything in it and doesn't seem hard to fabricate. Hopefully, 2x6 wall with R19 insulation in it is worth something as far as noise goes as well.

I keep mulling over the options. I don't quickly make decision haha. Today's unit of choice is now the Puma 5hp, 40gal, 2 stage. Putting this thing in the closet under my stairs to the second floor height is of a concern and the 60gal models are 71in tall and would waste a lot of space behind them. I would be able to use more of the closet if I go with the 40gal which for a single person shop likely should be plenty. If I ever do much blasting I would rather put an extra tank under or next to the cabinet vs starting with a 60gal I think.