Hypertherm Max-20

[M4RKE]

I have a max20 that has stopped working I have had a quick look at the machine and canot see anything that looks broken. The only thing that I can see that may be the problem is there is a small micro swicth that is in the torch head that is fixed to the brass body just behind where the tips and nozle screw on this is a normally open swicth that dont seem to be making contact at all what is its function and would this be the cause of the fault ?

TIA

 

[gordon stephenson]

Hello,
I have the powermax 45, and the micro switch you mention it to prevent the machine operating if the shroud and inner parts are not located correctly. the shroud should only tightened quite lightly with fingers only and at the same time the shroud should depress the micro-swith

 

[M4RKE]

Thanks for the quick reply Gordon do you have a picture of your torch with the cover off by any chance ?

Thanks

 

[astro_al]

They all have this check via a micro switch in the head. Your torches are different.

Why not use a continuity tester on a multimeter to find out if the switch is closing when you screw the bits into the head?

Al.

 

[M4RKE]

I have now got the swicth working and every time i take the shroud on and off the swicth is making and breaking but the machine is still not working ? so does anyone have ideas as to what may be the problem ? When I select the test position the air flows as it should but when I select run the air stops and the machine will not start

Thanks

 

[astro_al]

Trigger working?

 

[M4RKE]

I have tested the trigger back to the main unit and it to is making and breaking without any problems. What part of the unit does the trigger then control ? so that I can get to the next step of the elimation prcess

 

[Robotstar5]

Another interlock will be an air pressure switch, follow the air pipe in and it should go to a solenoid valve then a pressure switch before heading for the torch

 

[M4RKE]

Another interlock will be an air pressure switch, follow the air pipe in and it should go to a solenoid valve then a pressure switch before heading for the torch

Have just had a look at the air inlet and yes there is a pressure swicth there this is in the N/O state with no air applied so I guess this should change to N/C when air present ?

 

[Robotstar5]

Have just had a look at the air inlet and yes there is a pressure swicth there this is in the N/O state with no air applied so I guess this should change to N/C when air present ?

Should be able to test it when the machine is in "air pressure set mode"

Disclaimer: only test if you are confident/capable of working with covers removed on live equipment as high voltages are present!

 

[M4RKE]

Should be able to test it when the machine is in "air pressure set mode"

Disclaimer: only test if you are confident/capable of working with covers removed on live equipment as high voltages are present!

I am confident/capable of carrying out these test with covers removed but good of you to point this out. Is it that when this machine is in the test mode the air swicth is not in circuit as the air does flow when in the test mode ?

 

[Robotstar5]

Is it that when this machine is in the test mode the air swicth is not in circuit as the air does flow when in the test mode ?

The function of the pressure switch will not be used in "air flow test" mode but using that mode should allow you test the switch contacts are working?.

 

[M4RKE]

well the air swicth checked out ok so where should I be looking for this fault there is absolutley no sing of any arch tryiny to start

 

[Robotstar5]

Sorry, you've got me beat without a circuit diagram to follow I haven't worked on any plasma cutters, just drawing on 30+ years industrial automation fault finding techniques!
Hope some one turns up with more info

 

[M4RKE]

Is there anyware I can download a diagram from ?

 

[Robotstar5]

Is there anyware I can download a diagram from ?

Here you go Hypertherm document library

I will try and look at the circuit diagrams next week

 

[M4RKE]

Thanks for the link Im just back from me holiday so now its time to get this thing working. Did you get to have a look at the diagram Robotstar ?

Thanks

 

[Robotstar5]

Sorry been a bit busy with ebay and getting my bike through mot, will see if it's quiet at work this week and I can have a look at cct diagrams.

 

[M4RKE]

Cheers did the bike pass?

 

[Robotstar5]

Yes, bike passed

When machine is switched on and air connected you should have 2 green lamps (power & temp/pressure) if not, try the following (remembering you are working on live/high voltage equipment)

Meter set to AC >24V connect one lead to point 16 on drawing, other lead to 17 (checks voltage) then follow through 3A fuse - point 13 , 12, grey wire to 1TAS, grey to 2TAS, then yellow, if all OK you should have power to point 21 (violet wire to trigger). Operate trigger puts power to point 20 (another violet) then to points 6 (gas solenoid) & 8 (1CR & 2CR)

See what you can find?