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Topic Review (Newest First)
11-03-2009 07:04 PM
Jim Rockford When picking a compressor, Ignore the HP claims and look for one with the most CFM @90 seeing as how 99% of all tools are rated at 90psi. CFM is all that matters with an air compressor, NOT HP.
11-03-2009 07:03 PM
Torque454 That harbor freight compressor has some pretty decent specs. I saw a gas powered compressor there the other day that was the us general brand (or whatever brand it was, it was the harbor freight brand) that had a saylor beal 705 pump on it. That or a clone. Also had a kohler engine. Sounds like a pretty good compressor to me.
11-02-2009 08:04 PM
NEW INTERIORS
Quote:
Originally Posted by 302 Z28
If your running off 230v that works out to be about 1.5hp.

Vince
I'm running 220. I guess you learn something everyday.. No wonder it can't keep up with me !!!! I guess it did pretty good... 15yrs and not sure how many cars I did with it..
11-02-2009 07:57 PM
oldred
Quote:
Originally Posted by vintagecar
how do you figure the HP to Amp ratio to find out what the true HP is



Volts X Amps = Watts


746 Watts = 1 HP


But there's a lot of things to consider so it will never be an exact conversion when looking at motor ratings. Basically when you are looking at these single stage compressors with a 60 gallon tank most, if not all, will be 15 Amps or about 3 HP. A real 5 HP motor will be rated at least 21 Amps and can be more and any thing above a 21 Amp rating will have a believable HP rating anyway because then you are talking industrial types. Also the better companies are honest about the power ratings, for example Quincy numbers are believable as are Eaton's but IMHO Eaton has other issues that would cause me to avoid them totally. Ingersoll Rand is a very large company but even their 5 HP and smaller compressors have some very suspicious numbers so I would approach them with caution also. Of all places to find a good compressor the US General 2 stage at Harbor Freight is on sale quite often in your price range. These things are NOT made in China, the pump is from Italy and most of the rest of it is made right here in the USA where it is assembled. I have no first hand experience with these HF compressors but the US General I looked at last year had a USA made motor and electrics and later I discovered that even the tank is US made, it actually looks like a really decent outfit and when on sale they can be bought right! Use one of the weekly E-mail 20% coupons along with the sale price and these things can be bought dirt cheap!


http://www.harborfreight.com/cpi/cta...emnumber=93274


I have not used one of them, in fact I have never even heard one run but they look like a decently built unit and the parts quality looks to be a lot better than the McHome store types.

Those 20% off coupons can be found in a lot of sports and gun magazines also and with one of them that compressor is less than $700! I had not even realized those things could be such a deal until I looked them up just a bit ago, use that coupon when they are on sale in the store and we are talking a 22 Amp (5 true HP) 2 stage 60 gallon outfit for only a very few dollars more than those 3 HP units.


[EDIT] My mistake, it is the 7 1/2 HP compressor that has the Baldor USA made motor on it. Not sure where the 22 AMP 5 HP motor is made but it is an AO Smith brand.
11-02-2009 07:34 PM
302 Z28
Quote:
Originally Posted by NEW INTERIORS
Just walked to my shop in mine say's 15 amps..
If your running off 230v that works out to be about 1.5hp.

Vince
11-02-2009 07:32 PM
302 Z28
Quote:
Originally Posted by vintagecar
how do you figure the HP to Amp ratio to find out what the true HP is
I just use my handy dandy Square D motor data slide calculator. The actual calculations are based on the National Electrical Code 430-6.

Vince
11-02-2009 07:28 PM
302 Z28 That is probably 6 hp rated peak, which is a totally bogus rating.

Vince
11-02-2009 06:56 PM
NEW INTERIORS
Quote:
Originally Posted by vintagecar
so what is the HP stated and actual?

Mine say's 6hp..
11-02-2009 06:50 PM
vintagecar
Quote:
Originally Posted by NEW INTERIORS
Just walked to my shop in mine say's 15 amps..
so what is the HP stated and actual?
11-02-2009 06:15 PM
vintagecar I'm such a noob and sorry for upsetting the hotrodders gang and not doing as I was told... (my bad oldred)
I will continue my research and find a properly powered air compressor. how do you figure the HP to Amp ratio to find out what the true HP is
11-02-2009 06:08 PM
NEW INTERIORS Just walked to my shop in mine say's 15 amps..
11-02-2009 06:01 PM
302 Z28 [QUOTE=vintagecar]Alright...one more question... got a neighbor and we were talking about this stuff. He has a 10yr old "charge air" made by devbliss (sp?) it is a single stage, 60 gallon, 15Amp, 6.5HP compressor. [QUOTE]

No way, not possible, a 6.5hp motor is rated at 15 amps .

A 5 hp motor on 230v single phase pulls 28 amps
A 7.5hp motor on 230v single phase pulls 40 amps

This is prime example of the lies compressor manufactures try to pull on us.

Vince
11-02-2009 05:52 PM
NEW INTERIORS
Quote:
Originally Posted by vintagecar
Alright...one more question... got a neighbor and we were talking about this stuff. He has a 10yr old "charge air" made by devbliss (sp?) it is a single stage, 60 gallon, 15Amp, 6.5HP compressor. puts out 10.2SCFM @90psi and he siad he ran his DA sander just fine on his car projects without issue. The one thing he said it keeps up with, but barely is his high dollar HVLP gun. So...the amps on the $400-500 compressors are the same, 14-15 amps, and the SCFM is about the same, and they are single stage, but the HP of what I've been looking at is half of what his is. I can't find any that are in his HP realm that aren;t 2 stage and almost 1000 bucks?

I have that same Compressor.. Mine is 15 yrs old.. A DA Sander will give it he** !!! Believe me.. If you try to use it a lot it ''WILL'' start to pump water..
11-02-2009 05:47 PM
NEW INTERIORS
Quote:
Originally Posted by 302 Z28
DA sanders are one of the biggest air hogs. Any compressor smaller than a 5hp two stage will run continuously using a DA for an extended time.

Vince

Very true...
11-02-2009 05:44 PM
oldred
Quote:
Originally Posted by vintagecar
. So...the amps on the $400-500 compressors are the same, 14-15 amps, and the SCFM is about the same, and they are single stage, but the HP of what I've been looking at is half of what his is. I can't find any that are in his HP realm that aren;t 2 stage and almost 1000 bucks?

Go back and read what we told you about HP!

His 6 1/2 HP is PURE BULL$#%%!

He has a 3 HP motor on that thing no matter what it says it is on the tank. That is the same compressor you were looking at before, maybe a few cosmetic changes over the years but still the same 15 AMP THREE HP motor as the one you were considering. A real 6 1/2 HP motor running on 220 volts would be rated at least 30 AMPs.

As far as keeping up with the DA I seriously doubt he can run for more than just a very few minutes before having to wait on a recharge. Certainly it will run it OK and thousands of people do BUT they still have to give the thing time to catch up regularly and even more important than that, time to cool down.
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