r/AirCompression

Hi guys!
Wondering if any of you comp-boffins can shed some light on what my problem might be???
I've followed the wiring diagrams and the troubleshooting guides, consulted the internet and I think what the problem might be, that it's... fucked.
Okay, it's cheap(ish) generic Chinese unit.
Specifically, it's a Nuair Herkules 450/10/50, but I believe, apart from branding, it is identical to other units from companies such as Sealey, etc.

Problem is;
Plug it in, runs strong for a few seconds, and then slowly dies.

This sounds like a classic bad capacitor issue, right? That's what I thought...
So I bought a new 'un, fitted it... still does exactly the same thing.
I have noticed that if I bleed off the pressure, it'll fire right up again... then again die after a few seconds. I can repeat this cycle as much as I like, same result...
Clearly, as soon as there is pressure in the pipework, it overpowers the strength of the motor.
So I started disconnecting stuff, assuming I must have a bad/stuck valve somewhere.
First - I removed the pipes coming out the top of the cylinders, the machine ran really strongly, no stopping.
Then I reconnected them and disconnected the outflow pipe from the manifold that those first two run into, machine again runs strong. Okay.
Reconnected that.
Opened up the manifold that splits the airflow between the tank and the controls/gauges, strong running strong flow of air... and long story short, I did this with every joint, union, valve and connection in the system and I checked for blockages in the tank's ports everything open no obstructions...
In short - take resistance out of the system ANYWHERE and it will run really well all day, all night. The moment you close the system, you're back to runs for a few moments, then dies, till you bleed off the system again.

Anybody got any ideas what might be going on???
Losing my mind
Thanks guys

I'll include a few pics here of the wiring to the old cap - I wired the new one in exactly the same - could this be the fundamental mistake?

https://preview.redd.it/hhvlet9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=9f0ad810f3f70f07a5c4d7637d2365ba88e4d026

https://preview.redd.it/husr7t9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=f09d30be73db75a2dbb4c54ed666cdbc0ed6e45d

https://preview.redd.it/fxglqu9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=854daf52aff657a9c770e435fae3f126ac38d195

https://preview.redd.it/0yzv0t9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=6448f237acf725883a8c72bb19d9c890db076f69

https://preview.redd.it/5qadss9uqj2h1.jpg?width=3024&format=pjpg&auto=webp&s=beac1f492ddc462d9eba64a905ae7fbbb013cbab

https://preview.redd.it/brdu9t9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=9099ad2f4e2c9c1d65b7787325ba50fb8e17adb9

https://preview.redd.it/wbru8t9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=dfd672d5232946413962d35d5e20c9af3a5b6d45

https://preview.redd.it/mqwnzu9uqj2h1.jpg?width=4032&format=pjpg&auto=webp&s=ac253157f411f6d4f23517c8d28805d731a73c4a

https://preview.redd.it/xq7koeg1rj2h1.jpg?width=3024&format=pjpg&auto=webp&s=e29e0a7587d6d11b959e5897da1b329d2e56d3f8

https://preview.redd.it/fceuoeg1rj2h1.jpg?width=3024&format=pjpg&auto=webp&s=950f6b32eb15271f4948aa03f653f235711ffdd3

I really need help with this, at a loss on what I can find online.
I have an Atlas Copco XATS250 and I’m changing the compressor oil.
It takes Atlas Copco Paroil S, but I can’t get it fast enough. Is there a substantial equivalent that I can get my hands on in person at a hardware, parts store, etc?

Hey guys I’m wondering is anyone that has worked on atlascopco compressors and if they have had issues with them turning off randomly and wether or not it has anything with them turning e-stop button malfunctioning have

I have gone down the event list and this machine has had multiple events where the e-stop has been triggered but nothing else. I know no one is pressing the button so I’m unsure what could cause it to malfunction…..any input would Help thanks