Just bought an air compressor, and when I turn it on it starts to build up air but when it gets to around 20 psi the motor seems to be slowing down almost to a stop. Does anyone know what's up with this?
Why does the compressor bog down at low pressure
compressor
Related Solutions
You are correct that it is a good idea to use teflon tape on the threaded fittings, however no sealant is required or advised on the quick-connect part itself. These are designed to seal using internal o-rings.
There are multiple types of quick-connect air line fittings that at first glance appear similar, but are not necessarily compatible. It is very likely that you have connected two incompatible types, resulting in a leak. This is very common.
The two "main" types are often referred to as "automotive" and "industrial", though each can have sub-types that are typically letter designations, e.g. Industrial can be M, H or G. There's also a type called ARO, and one called Lincoln, but these are somewhat less common (at least in the US consumer market).
(image from Legacy Manufacturing)
The documentation for your air compressor may specify exactly which type of fitting you have. Otherwise head to the local big box store with your male coupling that leaks, and look for a similar-while-slightly-different male coupler to try.
Legacy manufacturing has published a very informative guide on the evolution of the various types of quick-connect fittings that lists the common types in use, with some images of each.
Milton Industries has also published a document that may help identify the type of plug you have, though their letter designations may not exactly match those of other manufacturers.
Dari Smart 25/2500 Compressor. 2HP Single Stage, Max 116psi
From the picture, it has a pressure switch, a tank gauge, regulator and regulator output pressure gauge.
The compressor should run till the tank is up to max pressure (116psi) and shut off. What is the Red Zone pressure? Usually Red means Dead and it sounds like the pressure switch has a failure and is not shutting the compressor off before going overpressure.
Amazing that no manuals are available online, I'd use the contact form on their website to see if you can have them email you an electronic equivalent if it's available.
Closeup
- Pressure Shutoff Switch -- Cuts off compressor motor when maximum pressure is reached to prevent over-stressing pump and components.
- Main Tank pressure -- maximum level reached is controlled by Pressure Switch, operation in the red zone indicates switch failure.
- Regulator Output Pressure Gauge -- Shows the regulated output pressure
- Pressure Regulator -- Use the knob on the pressure regulator to set pressure on the Output Pressure Gauge, set to pressure recommended by tool or paint sprayer attached to the compressor
Best Answer
This is the same thing that happens when you use an extension cord of insufficient gauge to power a compressor, as you say, it's insufficient power. Of course, it will try to pull sufficient power, and if it succeeds, probably light the extension cord on fire.