Gas compressor conversion

[Jetsurgeon]

Hi, I have an 8HP gas Emglo with a 17 Gal tank and a 4 cyl LU single stage pump, I want to convert it to electric, and looking around it looks like all I really need to do is get a 3HP Compressor Duty motor, remove the pilot valve and route a pipe to a differential pressure switch and wire the motor to that, and determine appropriate pulley size for the setup to get the desired RPM range on the pump (between 882 and 946 according to the MFR determining on 100 or 150 psi)...am I missing anything?? Thanks

 

[infinkc]

Maybe cheaper to sell the gas one and pickup an electric?

 

[Jetsurgeon]

I figure I am only looking at maybe $300-400 in parts, and it makes 15-18 CFM

 

[csp]

You're not going to get 15-18 cfm with a 3hp motor. A good rule of thumb is max 4cfm per horsepower.

 

[Jetsurgeon]

From the Mfr:

 

[nadogail]

IMHO, Gas powered compresssers sell for more than the electric ones.

 

[The Cobbler]

you will need to have an unloader valve at the pressure switch , also a check valve between the compressor and tank with the unloader line between the compressor and check valve

 

[redmondjp]

you will need to have an unloader valve at the pressure switch , also a check valve between the compressor and tank with the unloader line between the compressor and check valve

Are you thinking that the gas-powered compressor doesn't have a check valve at the tank and uses the compressor head valves for this purpose? Most gas-powered compressors that I have worked on still have a check valve where the discharge line enters the tank.

 

[The Cobbler]

^^^ you may be right. . but the unloader needs to be re worked.
I have a EMglo twin tank gas compressor & it doesn't have a check valve tho

 

[redmondjp]

^^^ you may be right. . but the unloader needs to be re worked.
I have a EMglo twin tank gas compressor & it doesn't have a check valve tho

Agreed on the unloader - fortunately you can buy a new Square-D pressure switch/unloader on Amazon for around $40.

What pump does your Emglo compressor use? It must use the discharge valve(s) in the head for the tank check valve.

 

[sberry]

I agree with sell and buy. That chart should be for sale,, print air.

 

[Jetsurgeon]

It's an Emglo LU pump, which means it has unloaders built into the head of all 4 cylinders, and the differential pressure switch has an unloader as well. My Emglo is the 17gal and also does not have a check valve at the tank.

 

[walta]

No reason to delete the pilot valve.

I bought a compressor with an electric motor and a pilot valve it seemed strange at first I have grown to like it. I never forget turn off the compressor and am awakened at 2 AM when the compressor starts up. Once the compressor unloads the power draw is very small. Even when I know the compressor is on the sudden sound always startle me.

Walta

 

[redmondjp]

No reason to delete the pilot valve.

I bought a compressor with an electric motor and a pilot valve it seemed strange at first I have grown to like it. I never forget turn off the compressor and am awakened at 2 AM when the compressor starts up. Once the compressor unloads the power draw is very small. Even when I know the compressor is on the sudden sound always startle me.

Walta

Well, if you are using the compressor on a continuous basis, this is exactly what you want to do anyways. The motor windings get very hot every time it starts up, and most motors are only rated for so many starts per hour.