Air compressor help

alumarine said:
Absolutely if you use the appropriate connector.
Were you planning on crimping it?
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Yes. Planning on crimping it. Just wasn't sure if it's safe to jump from 10gauge to 8-6gauge.

Because like I said I do not want to go inside the compressor and take half of it apart just to change out the wires.

Going to do it like this. Extended wires with proper but connector. Add alligator clips, add breaker. Done

Why yo need open air chuck ? If there's no tank?
 
shootmymime said:
You don't need a switch, That's what your pressure switch is on the tank.
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You do if you want to be the one to determine when the system if pressurized and when it isn't.

Any compressor install should include a switch to be able to disable the system independent of the pressure switch.

Edit: I see the on/off lever on the existing, non-functional switch.

OP you DO want to replace that pressure switch with another one. Do not go to a manual on/off switch without adding a pressure switch. You could easily blow up the compressor.

I kinda thought from the original post that it looked like a Puma.
 
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csp said:
You do if you want to be the one to determine when the system if pressurized and when it isn't.



Any compressor install should include a switch to be able to disable the system independent of the pressure switch.



Edit: I see the on/off lever on the existing, non-functional switch.



OP you DO want to replace that pressure switch with another one. Do not go to a manual on/off switch without adding a pressure switch. You could easily blow up the compressor.



I kinda thought from the original post that it looked like a Puma.
Click to expand...



That's what I meant. You need a pressure switch, not a rocker switch.


Sent from my iPhone using Tapatalk
 
csp said:
You do if you want to be the one to determine when the system if pressurized and when it isn't.

Any compressor install should include a switch to be able to disable the system independent of the pressure switch.

Edit: I see the on/off lever on the existing, non-functional switch.

OP you DO want to replace that pressure switch with another one. Do not go to a manual on/off switch without adding a pressure switch. You could easily blow up the compressor.

I kinda thought from the original post that it looked like a Puma.
Click to expand...

The pressure switch is ONLY if you are using a tank. I'm not using the "yellow" tank. There for there won't be any pressure building up. Correct me if I'm wrong. But I do not see a reason for a pressure switch when your not running the tank. Every compressor I seen without a tank had a simple on/off switch.

Looking at the viair portable compressor. It to does not have a pressure switch.
 
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You can get a new pressure switch for about $10.

Surplus Center

A pressure switch is a good idea even if you don't run a tank. The air hose acts as a small tank, and you don't want to over pressurize it if you have a sealed fitting on the other end, such as a standard air coupler.

That compressor looks very similar to the 12v Puma models. Here's one with a comparable 3/4 hp running and 3.4 cfm. It is rated at 30A draw.

Puma 12 Volt 1.5 Gallon Oil-Less Air Compressor Free Shipping Oiless 12V | eBay

I've used a similar Puma for years. The factory wires are ~12 awg and while they get warm they do not get overly hot. A 40A or 50A fuse should be fine, the compressor will draw a little more when starting under load, but it is a transient spike and should not pop a slow blow fuse.

https://www.delcity.net/store/Fuses-&-Fuse-Accessories/

Wire size is going to depend on the length. For short wires (5' or so) you can get by with 10awg, any longer and I'd recommend 8 awg.

As mentioned previously 1hp = 745.7w, so 3/4 hp = 559w which is 46A @ 12v. But... just because the motor is rated at 3/4 hp continuous does not mean it is running anywhere near that level in normal use.

- Matt
 
Thanks bud. But not going to run a pressure switch. Because I'm not running a air tank. Every pressure switch I see is on a compressor with a air tank. Every compressor without a air tank. Has a manual on/off button. Look at all the portable viair compressor. No pressure switch. Plus a pressure switch does get hooked up to a tank. It has extra holes.
 
kolelt said:
Thanks bud. But not going to run a pressure switch. Because I'm not running a air tank. Every pressure switch I see is on a compressor with a air tank. Every compressor without a air tank. Has a manual on/off button. Look at all the portable viair compressor. No pressure switch. Plus a pressure switch does get hooked up to a tank. It has extra holes.
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I work on air compressors and air systems for a living. Usually MUCH bigger ones (100+ HP) so I feel I can give some good advice here. Without a pressure switch, what is going to stop the pump once it reaches pressure? It's going to compress air until it literally can't anymore or until it pops of whatever safety valve it has (but those are usually installed on the tank) I'm sure those other pumps use some sort of unloading device or a pilot valve to stop air compression.
 
JRZEE2000TR4LTD said:
I work on air compressors and air systems for a living. Usually MUCH bigger ones (100+ HP) so I feel I can give some good advice here. Without a pressure switch, what is going to stop the pump once it reaches pressure? It's going to compress air until it literally can't anymore or until it pops of whatever safety valve it has (but those are usually installed on the tank) I'm sure those other pumps use some sort of unloading device or a pilot valve to stop air compression.
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Me?
Show me a pressure switch for no air tank?

I looked through all the portable viair compressor. Not one has a pressure switch. Because your not pumping 100+ PSI into tire. Once your done and moving to next tire. I highly doubt it will pressurize.

What are you going to set the pressure switch to without a tank ? How would you hook it up without a air tank?

Thank you for your help info.
 
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My arb has a pressure switch. It shuts off when the hose is pressurized. Without the switch, you're going to be stressing the hose if it's not continuously flowing. If you turn the compressor on with a hose connected and standard chuck, it will start building pressure in the hose until you open the line. If left unopened, it will blow the hose as the compressor keeps trying to fill it. The air pressure has to go somewhere! Now, that being said, you could hook the inflator up to the tire, turn on the compressor and then turn it off when the desired tire pressure is reached, but if you delay for anything and pressure keeps building in the hose, it will blow. Pressure and heat will blow a hose pretty quick.
 
NWFLBowhunter said:
My arb has a pressure switch. It shuts off when the hose is pressurized. Without the switch, you're going to be stressing the hose if it's not continuously flowing. If you turn the compressor on with a hose connected and standard chuck, it will start building pressure in the hose until you open the line. If left unopened, it will blow the hose as the compressor keeps trying to fill it. The air pressure has to go somewhere! Now, that being said, you could hook the inflator up to the tire, turn on the compressor and then turn it off when the desired tire pressure is reached, but if you delay for anything and pressure keeps building in the hose, it will blow. Pressure and heat will blow a hose pretty quick.
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Makes sense to me....
 
Any recommendations on type of pressure switch to use on this set up without a air tank.
 
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kolelt said:
Yes. Planning on crimping it. Just wasn't sure if it's safe to jump from 10gauge to 8-6gauge.

Because like I said I do not want to go inside the compressor and take half of it apart just to change out the wires.

Going to do it like this. Extended wires with proper but connector. Add alligator clips, add breaker. Done

Why yo need open air chuck ? If there's no tank?
Click to expand...

all of this previous conversation would be handled with an OPEN air chuck. with an open chuck it cannot build pressure. just like all the other portable compressors.

you are correct, no need for a pressure switch for what you are doing, a portable compressor.

I WOULD put in a pop-off valve though.
 
kolelt said:
It's only 5amp?

Yea open air chuck !
Click to expand...

5 amp is plenty. You wire it on the coil side of the relay in line with your control switch. I think it is an excellent idea. It takes no time at all for a 3/4hp compressor to overpressure a hose. Even an open tire chuck might not be able to bleed all the air that beast puts out. I would not want an exploding air hose in my hand, so I would have both a physical overpressure valve AND a pressure switch like my shop system does, but that's me. I like my hands.
 
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kolelt said:
Me?
Show me a pressure switch for no air tank?

I looked through all the portable viair compressor. Not one has a pressure switch. Because your not pumping 100+ PSI into tire. Once your done and moving to next tire. I highly doubt it will pressurize.

What are you going to set the pressure switch to without a tank ? How would you hook it up without a air tank?

Thank you for your help info.
Click to expand...

Don't really understand you're questions here. That pump is designed to flow into a receiver and load and unload off of the pressure switch. The unloader valve for the discharge pressure is built into the pressure switch also. That's what that one line going up the back side of the switch is. Without the switch you have no control over the air at all. Most small systems I work on (less than 5HP) use the pressure switch as the starter. I personally dont like running FLA across a set of pressure switch contacts. As others have stated, the best way to do it is to set up a control circuit in series through the coil side of a relay and the pressure switch. with the load of the compressor through the contact side of the relay. Super simple circuit to wire up.
One other thing, the main problem with not using the tank and just going into a hose is whatever switch you use, either the one already on the tank or the one in a previous post is you will be short cycling the pump, meaning it will be starting and stopping quickly which will wreak havoc on all the motor and relay.
 
TheDurk said:
5 amp is plenty. You wire it on the coil side of the relay in line with your control switch. I think it is an excellent idea. It takes no time at all for a 3/4hp compressor to overpressure a hose. Even an open tire chuck might not be able to bleed all the air that beast puts out. I would not want an exploding air hose in my hand, so I would have both a physical overpressure valve AND a pressure switch like my shop system does, but that's me. I like my hands.
Click to expand...

uh, yes an open chuck will work perfectly.

my smitty puts out more than this pump, by default they come without a pressure switch, and an open chuck. It works great.


if he was going for a hard mount pump, with a tank, absolutely yes to a pressure switch. but for what hes trying to do, there is no good reason for it.
 
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