Condor MDR3 Air Compressor Pressure Switch 

Hi Adam, We recommend a 20-24Amp pressure switch for a 10HP compressor. Kind regards

You would normally use the MDR1 for single phase - see ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tkux63uJ-t8.html or www.airlines-pneumatics.co.uk/pneumatics/air-compressors-and-dryers/compressor-pressure-switches/condor-mdr1-compressor-pressure-switch/S020122

Yes, the differential on the mdr3 is adjustable. If the set cut in pressure is 3 bar the cut out pressure can be set anywhere between 4 and 7 bar so 3-4 bar is your 15psi.

@@andrewrogers9906 3 Bar is only 43psi i need 110 cut in to 125 psi

On a normal piston compressor there is a pipe from the compressor to a non return valve which is fitted to the receiver. When the compressor stops the unloader valve on the pressure switch vents the air in this pipe so that when the compressor starts next time it is not working against pressure. Therefore you will normally get an air exhaust noise each time the compressor stops but that should cease directly. If the non return valve on the receiver becomes faulty then air can leak from the receiver and out through the unloader on the pressure switch. This often leads to a call reporting a leaking pressure switch - always the first thing to check then is the non return valve. This non return valve can be subject to very high temperatures and has a seal which should replaced on a routine servicing basis.

have the same problem is there some pics of the service routine on the replacing the seal ???

Translated, the question was "how to adjust the lower pressure limit?" The cut in and cut out pressure can be set by turning the collaboration screw as shown in the video.

first line you enter with neutral, second one you enter with phase then you put a wire from the exit of that phase and put it on the entry of the 3rd line, so that now you have 2 exit availlable, one for neutral and one for phase.