The compressor has a max working pressure of 12 bar but at the moment is maxing out at 7.5 bar how do i adust it

Most pressure cut off switches have an adjustment screw on them where you can dial in the cut off/turn on pressures. Take a look and see if you have the adjustment screws. If you have the switch model, you can try looking up online to see how to make these adjustments.

2 possible actions to have to get what can blow off. 1. there is something dirt or corrosion in the check valve if its blows out on the pressure relief valve its under on the black hoseline right on the pressure switch point 2 . it can also be the safety valve will open if the pressure is adjust set to high. or like CONTIMAC compressors has often this problem. 8 bar safety valve on a 8 bar adjusting is very tight taken on factory then you will lower the adjustment to over 7bar max thats most times the max presure for airtools !! or replace a good choice with 11 bar = 159.5418 psi safety valve if thats the point .then its solved.


Another fix in an failure when is when there are metal parts are used there can be metal parts come of out of a membrane or another metal part that and come between the check-valve on the tank where you must clean the metal pieces the relief of the pressure switch remains on a rusty metal particle in the non-return valve

This number is for the D20114 its the safety valve that can not be set to a max basic pressure .
its strange but its not adjustable it can be defect i have one time the same the experience there is not a adjustable Pressure Switch on this model , the moast compressors have a 8 to12 bar adjustable.pressure switch.
Very important This safety valve gives an electronic brake between the pump and to a end of top about 10 bar . if its not switching off then a drain valve opened . and blows all the air out. (but only over 10 bar ) the max pressure on the tank , the moast tools are working on a pressure from 6 to 8 bar.
-----------------------------------------

Checking Safety Valve
WARNING: Risk of bursting. If the safety valve does not work
properly, over-pressurization may occur, causing air tank rupture or
an explosion.
Before starting compressor, pull the ring on the safety valve to
make sure that the safety valve operates freely. If the valve is
stuck or does not operate smoothly, it must be replaced with the
same type of valve.
Draining Air Tank (Fig. 1)
WARNING: Risk of unsafe operation. Risk from noise. Air tanks
contain high pressure air. Keep face and other body parts away from
outlet of drain. Use safety glasses when draining as debris can be
kicked up into face. Use ANSI S12.6 (S3.19) ear protection as air flow
noise is loud when draining.
NOTE: All compressed air systems generate condensate that
accumulates in any drain point (e.g., tanks, filter, aftercoolers,
dryers). This condensate contains lubricating oil and/or substances
which may be regulated and must be disposed of in accordance with
local, state, and federal laws and regulations.
1. Ensure On/Off switch (A) is in the OFF position.
2. Move compressor into an inclined position so drain valve (H) is
at the lowest point (this will assist in removing moisture, dirt, etc.
from air tanks)
3. Place a suitable container under the drain valve to catch
discharge.
4. Grasp black lever on drain valve.
5. Slowly rotate lever to gradually bleed air from air tank.
6. When air tank pressure gauge reads 10 PSI (275.1 kPa), rotate
valve to the fully open position.
7. Close drain valve when finished

Hi
your pressure switch is bad. so it isnt cutting off the compressor. the part number is N003306SV and can be obtained from Dewalt on Servicenet.
Detail

Good luck and hope this helps

Type Komatsu sk1020
Pump Gear
Max. flow - auxiliary hydraulic 21 gal/min 80 ltr./min
Max. pressure - auxiliary hydraulic 3,045 psi 210 bar
Control valve 3 elements fully Servo-controlled
High flow auxiliary hydraulic system "SUPER FLOW" (OPTIONAL):
Max. flow 34 gal/min 130 ltr./min
Max. pressure 3,045 psi 210 bar

cheers
Joe
www.barter-joes.com

The pressure switch should be at the factory setting of about 120# max. Not to be hurtful,but what you discribe is normal. Even a 2 HP 220V is minimum for a compressor.. You go by the CFM Rating. You and I can not afford a two thousand dollar 12 CFM Unit. Your compressor is simply too small, to do much. It is pushing against tank pressure so much,after 90# that the reed valves can't hold it. Set it at 100 to 120. It is not designed to run up to 150 max. Now if it is,an oiless compressor , it won't last long. My Campbell- Hausfeld lasted 31 years. Got a new one two years ago

Hello,
There are a few things that will cause a compressor to trip the breaker.
The main one is by using an extension cord. Compressors pull a lot of juice, even small ones. Therefore it's recommended that you use a longer air line instead of an extension cord. If you need to use one then you need to get one that may seem overkill. The best place to find one is a boating supply shop. Shore power extension cords do the job nicely.

Another issue is related to where you live and the time of year. If you are in a colder climate (like me), then you may need to stick a space heater next to it for 10 minutes. Compressor oil is straight 30. Even if it's a "Oil-less" design.
If you are in a warmer climate then you shouldn't be messing around with a compressor unless it's to air up a raft. ":-}

The last problem has to do with the unloader valve. When a compressor reaches it's max psi there is a momentary pressure release. This is the pressure that remains in the compression cylinder and the tank check valve. With out this release the piston needs to work against the max psi when it starts. This will cause the motor to sound as if it's laboring. This lasts about 10 to 12 seconds then it trips the breaker.
However the compressor would need to have started and worked up to or close to max psi. Only after it restarts will it have this issue.

Yea I know it's a lot of info but I like to be thorough.

The only other things that might cause this is an electrical problem usually found when there are to many other items on the circuit. A compressor should have a dedicated circuit but that's not really practical with smaller portable compressors.

I hope something here helps but if not please let me know and
I'll try and figure out the problem with you.

When you add refrigerant to the system the compressor will start to cycle again. The system needs a minimum refrigerant pressure to work so when the pressure falls below that minimum the compressor wont cycle. If your adding freon yourself make sure to have engine running and the ac on max with the fan on max. As your adding freon the compressor will start when the min. pressure is achieved, watch the pressure gage closely so you don't over do it. I hope this helps you.

Yes,but if the max is 125 you don't want to increase it above 110 and set off the pressure relief valve.

It looks like there might be a knob which sets the max air pressure coming from the compressor. If there is one, this may have been turned down.

There are usually 3 pressure settings on an electric compressor. Compressor max, pressure switch cut on, and pressure switch cut off.