Old Airmaster Pressure Switch Setting

[Matt Swinn]

Hi. I have rebuilt an old Airmaster compressor which now works a treat! All I need to do now is set the cutoff and cut in pressures.. any idea how I do this.. I assume the tap looking thing needs to be turned but I'm unsure which is which... See attached file. I can't seem to find anything on the internet to do with this pressure switch.

Any help would be appriated!

Thanks, Matt

 

[brightspark]

well it looks like u just press the dial down and turn either way to increase pressure or decrease it and the pin locks it in . it may not have differential u can adjust between pressures . just run it up and set it looking at pressure gauge then see what it cuts back in at by letting pressure out. if u haven't altered it just run the machine . it probably wont need setting

 

[rtbcomp]

That's slightly unusual. From the marking turning the knob clockwise will increase the cutoff pressure (P), but the same knob has the markings which suggest that will decrease the difference between cut-out and cut-in pressures (∆P hysteresis).

Normally there are 2 different adjusters.

well it looks like u just press the dial down and turn either way to increase pressure or decrease it and the pin locks it in . it may not have differential u can adjust between pressures . just run it up and set it looking at pressure gauge then see what it cuts back in at by letting pressure out. if u haven't altered it just run the machine . it probably wont need setting

Perhaps you rotate it to adjust the pressure and press, twist and release to adjust the hysteresis? Or vice-versa.

As said, suck it and see.

For some reason some manufacturers say adjust the setting with some pressure in the tank.

 

[Seadog]

It looks very similar to the pressure switch on my Hydrovane. Rotate one way to set upper limit and press down and rotate the other way to set lower limit.