Help Me Choose An Air Compressor - Page 2 - PeachParts Mercedes-Benz Forum

Father Of Giants · #16 07-07-2017, 11:12 PM

Quote:

Originally Posted by 97 SL320

The two phase part of the above post isn't accurate. House power in the US is "split phase " though it is generally called "single phase".

The easiest way to visualize 1, 2 or 3 phase power, think of a 1 , 2 or 3 cylinder engine.

With obsolete two phase power, the second phase sine wave is offset by 90 * ( quarter of a wave ) . The circuit was generally fed with 4 wires and motors had 2 separate windings to consume the power. https://en.wikipedia.org/wiki/Two-phase_electric_power

With single " split " phase house power, sine waves are 180 * offset ( half of a wave ) . These systems have 3 wires but only use 2 depending on if 110 or 220 voltage is needed. No matter the voltage, everything remains consuming single phase. Motors have one winding that is used for run. ( There is sometimes a start winding that drops out after the motor is turning but that is beyond the conversation here. )

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiXzuCKivjUAhXGyj4KHanNCPwQjBwIBA&url=http%3A%2F%2Fwww.globalspec.com%2FImageRepository%2FLearnMore%2F20122%2F240120SinglePhaseWavefor mTransparente0e210f2a73b4e2aa95274447e1b5892.gif&psig=AFQjCNHtmjLOfLLyT6KVjHAbdiLmzvDx9g&ust=1499547921437169

With single phase house power, one can get 110 by selecting a hot and a neutral. To get the other "phase " of 110 you select the other hot and same neutral. To get 220 you select both hots.

Three phase power is used for generation and distribution to your neighborhood. It is also used directly by industry. With 3 phase power, the sine waves are offset by 120* ( third of a wave ). This is very efficient because the power transmission is smoother and motors less expensive / more reliable. Motors have 3 windings.

I don't know the current rate , but don't see an electrician charging more than a few hundred $ to install a 220 system if the wire / outlet can be fastened to the wall. For a short run materials would be sub $ 50 and take an hour.

Installing a 220 V outlet differs only slightly from a 110 v outlet. The actual wire is the same, the breaker needs to be a 2 pole ( we are using both hots ) and the third terminal is a safety ground not a part to pickup 110 V. If the device like a clothes dryer needs 110 to run the motor and 220 to run the heater, 4 wires must be used ( 2 hots , one neutral and a safety ground )

At higher voltages, a smaller wire diameter can be used Vs running the same load at a lower voltage. A three hp single phase motor running at 220 V will consume 13 amps , A 14 wire gauge extension will work though the thicker 12 gauge is better. ( for house wiring, 14 G is good to 15 amps and 12 G to 20 )

The oven socket will be rated for 50 amps so the plug won't work directly. You could make a jumper cord to a 220 V 15 A socket but in theory the cord should have it's own breaker. Breakers are rated for expected load and wire size. If a compressor that consumes 13 A locks up and the load goes higher, the breaker won't trip the the compressor will become a heater element.

So essentially the 220v compressor will work, but will need a special extension cord correct?

Also, can I just buy the cord or do I literally have to build it from scratch?

Father Of Giants · #17 07-07-2017, 11:23 PM

It also seems the 220v compressor is just too much of a hassle to convert for home use.

Mxfrank · #18 07-08-2017, 07:18 AM

Quote:

Originally Posted by Father Of Giants

So essentially the 220v compressor will work, but will need a special extension cord correct?

Also, can I just buy the cord or do I literally have to build it from scratch?

There are several different 220 outlets, depending on the current rating and whether or not it's a locking plug. Assuming the socket on the compressor is the same as your oven plug, you can probably find an extension at an electric supply house. Otherwise, you'd need a custom cord:

StayOnline.com Custom Power Cords (NEMA, IEC-320 or IEC-309) - Cable Assembly & Pricing

Either way, the extension cord will cost more than the used compressor.

Father Of Giants · #19 07-08-2017, 07:35 AM

Quote:

Originally Posted by Mxfrank

There are several different 220 outlets, depending on the current rating and whether or not it's a locking plug. Assuming the socket on the compressor is the same as your oven plug, you can probably find an extension at an electric supply house. Otherwise, you'd need a custom cord:

StayOnline.com Custom Power Cords (NEMA, IEC-320 or IEC-309) - Cable Assembly & Pricing

Either way, the extension cord will cost more than the used compressor.

Yeah, i'll pass on the 220v compressors then.

Looks like i'll get the weird V twin compressor then.

barry12345 · #20 07-08-2017, 09:30 AM

A 110 volt compressor on a normal 15 amp 14awg wire gauge will only tolerate about one electrical older rated horsepower. It would take a 110 circuit Much stronger to handle the claimed horsepower of the newer compressor. The news is not the only fake thing out there.

There is also a chance that that 220v motor can be converted to a 110 by switching a couple of wires. That information should be on the motor plate. But you should feed it with a ten gauge wire then and a 30 amp breaker if it is. The original intent of using 220v was to keep the wire gauge size needed down.

97 SL320 · #21 07-08-2017, 09:40 AM

If you are going to get a 110 compressor, keep the power cord as short as possible then use more air hose, this reduces voltage drop that can burn the motor out.

In any event, a 220 cord of sufficient wire gauge won't be any more expensive than one for a 110 compressor. Have a look on a home center web site for bulk extension wire and plug / socket ends then make your own. It may even be less expensive to buy a pre made 110 cord and cut the ends off.

None of this is as difficult as some make it out to be.

Diesel911 · #22 07-08-2017, 09:59 AM

Quote:

Originally Posted by Father Of Giants

So essentially the 220v compressor will work, but will need a special extension cord correct?

Also, can I just buy the cord or do I literally have to build it from scratch?

Or more Air Hose to reach your work area.

I bought Harbor Freight 2 hp 8 gal tank 110-120 volt and the typical 125 psi. As a handier supplement my Cambel Hasfield 220Volt don't remember the other specs but the Motor and Pump are much larger then the Harbor Freight one. It originally cost $260 in 1980 something Dollars.

If you go to Harbor Freight you can look at user reviews of the products. Likely the same with Sears or Amazon. You can look at the reviews and pic a model you like and then use that info to shop around.

Some of the items I used to frequently use compressed air for that taxes the Compressor is using a Metal Cutoff Wheeled Tool or Grinding Tool.

As a home mechanic I have seldom used pneumatic impact wrenches unless for some tough specific task.

I mostly use Harbor Freight 12 volt Impact Wrenches (which are actually made for removing lug nuts/bolts; I have one in each Vehicle) and they have nearly always substituted OK for the penumatic impact wrenches.

HuskyMan · #23 07-08-2017, 10:38 AM

First, I'm not an electrician. That said, I've spoken with several of them about this issue. One told me that if you are planning on running welders, hot tubs or powering up an RV sitting on the driveway, you need to have your service upgraded from 100 amp to 200 amp.

Also, I found this website for converters, looks like this may be a possibility for you.

https://www.110220volts.com/power/voltage-converters.html

Does anyone know if a 220v device pulls more amps than a 110v?

Mxfrank · #24 07-08-2017, 12:47 PM

I wouldn't suggest a step up transformer for anything bigger than an electric razor. If you need 220, just have an electrician wire an outlet for you.

BillGrissom · #25 07-08-2017, 01:01 PM

For a decade, I used the HF cheap one w/ dual side tanks, 2 HP motor, and top handle. It appears to be diaphragm type (no belt). Worked OK for most jobs but say nailing fence boards w/ an air nailer required waiting occasionally for it to recharge. I painted a car door with it, and if you paint slow and careful it might keep up even on a whole car. Then it started not reaching cut-off pressure, running all the time. I suspect a cracked diaphragm or such. Been sitting until I take it apart someday.

I later got a larger 5 gal belt-driven Rand 4000 w/ horizontal tank and 2 wheels for $25 at a garage sale. When first tested on 120 VAC, the motor would often stall and trip the breaker. I re-wired for 220 VAC (single-phase) which is an option, and no stalling since. I ran a large drier cord (30 A?) 8 ft to a wall socket. I installed the socket where my former electric water heater used to sit in the garage (now use gas). Since a plug, I could relocate the compressor, but that is the only such socket at my house. But, I have used it to all around my 1/3 acre home (nailing fences, roof). I just chain 50 ft air hoses to reach. The air hose acts somewhat like a reservoir, so actually seems to help.

Dan Stokes · #26 07-08-2017, 04:11 PM

Bill - as a follow-up to your post..... My compressor is on a dedicated 220 service in the shop (the compressor is screwed to the floor) but I wired it with a dryer-type plug. With 100 amp service in the shop I can easily unplug the compressor and plug in the 30' extension cord to the welder (I forget the wire gage but it's significant and heavy!) and run the welder pretty much anywhere in the shop. Works great. There isn't enough power in the shop to run the welder and the compressor at the same time along with the AC and other power tools and this way I CAN'T screw up and do that. So I think you've done exactly the right thing.

Dan

Father Of Giants · #27 07-09-2017, 08:36 AM

Ok guys I have to come clean, I got the air compressor but it failed.

The capacitor blew, the motor is probably burned out.

The motor was a dinky 1/2hp unit, it is powering a compressor of at least 2hp capability a V Twin, so I can either source a 2hp motor or just buy a another air compressor out there.

I looked on ebay and craigslist and the price for a new motor, whether new or used in most cases cost more than the entire used compressor.

Long story short the compressor is FAR to powerful for the small motor to handle.

Either way, I might just buy either a new motor or another used air compressor.

Shoulda got the smaller one instead of trying to get something bigger...

Now i'm back at square one

I really should of taken you guys advice, sorry.

leathermang · #28 07-09-2017, 08:50 AM

Quote:

Originally Posted by Father Of Giants

Ok guys I have to come clean, I got the air compressor but it failed.

The capacitor blew, the motor is probably burned out.

The motor was a dinky 1/2hp unit, it is powering a compressor of at least 2hp capability a V Twin, so I can either source a 2hp motor or just buy a another air compressor out there......

I do not know how much running capacity you need....
but if you can get that electric motor replaced under warranty

you might could just change the pulley ratios .... to match its abilities to the friction of the V Twin.... it would run more for sure... perhaps a temporary solution to get this job done while you wait for sales ...

Father Of Giants · #29 07-09-2017, 09:03 AM

Quote:

Originally Posted by leathermang

I do not know how much running capacity you need....
but if you can get that electric motor replaced under warranty

you might could just change the pulley ratios .... to match its abilities to the friction of the V Twin.... it would run more for sure... perhaps a temporary solution to get this job done while you wait for sales ...

Is this a good website for pulleys?

https://www.grainger.com/category/v-belt-pulleys/sheaves-and-pulleys/power-transmission/ecatalog/N-hxd

How do I go about doing this? As in finding the correct pulley style and size?

Also what do you mean by running capacity? The CFM it can output?
I would like for the compressor to put out a high enough static pressure so I can get the correct working PSI of 90. I'm aware working PSI is dependent on hose length and how much static PSI you have available.

My fear is that even with the correct pulley set up, the compressor won't be able to get to the correct static pressure OR it will takes eons to do so. Should I be concerned about such a thing?

What would you do in this situation?

leathermang · #30 07-09-2017, 09:37 AM

Quote:

Originally Posted by Father Of Giants

Is this a good website for pulleys?

https://www.grainger.com/category/v-belt-pulleys/sheaves-and-pulleys/power-transmission/ecatalog/N-hxd

How do I go about doing this? As in finding the correct pulley style and size?

Also what do you mean by running capacity? The CFM it can output?
I would like for the compressor to put out a high enough static pressure so I can get the correct working PSI of 90. I'm aware working PSI is dependent on hose length and how much static PSI you have available.

My fear is that even with the correct pulley set up, the compressor won't be able to get to the correct static pressure OR it will takes eons to do so. Should I be concerned about such a thing?

What would you do in this situation?

Grainger is a site you can get just about Everything from.. usually at THREE or more times the cost of other places.. but sometimes you can't find those other places....so it is a nice emergency solution.

IF you are going to try to do this.. which I only mention but do NOT advise...
go to your nearest BEARing supply....which will usually also have pulleys
and ask for the PAPER catalog of things like Browning power transmission ....

You might need to make a step down mechanism between the motor and the air compressor pulley.... since it has a fan included in it i assume..

the load .. usage at the equipment... is important main factor..

but you mention other important factors... the length AND size of the hose.. can really make a difference on things needing constant pressure.. like a paint spray gun... which really needs a whip and a pressure gauge AT the sprayer's belt line to see if the system is providing the air capacity at the speed needed to do proper atomization.. ( of course I am describing the stone age... not the newer spray systems meant to save over spray )

You ARE Worrying about the correct potential problems...

so a new minimum Five hp ACTUAL hp compressor may be what you need... and make sure you have the biggest of hoses you can afford... ( a problem finding the brass connection hardware may present itself ) which I hope someone will tell me how to resolve with my 5/8ths inside diameter hose ...

The way they are allowed to describe ( which should be illegal ) causes many people to buy under what they need for their jobs...

You will need to really research to make sure you get what you need.... ' over capacity' is a really good thing... some day you might want to hook up two loads at the same time...