I have had my compressor for quite a while, and has performed very well (better than me ). It's a AS186 compressor, available under many names, and has a reservoir tank. My normal spray pressure is between 10 & 20 psi (0.6 to 1.2 Bar). Recently I noticed it running hot, but more importantly the compressor was running continuously. The compressor has a pressure switch, when the cylinder pressure drops below 3.0 Bar the compressor switches on, and switches off when the reaches 4.0 Bar it switches off. My spray pressure remained constant, so I was not getting lack of air. To track down the fault I increased the air pressure on the regulator (on the compressor output with the water trap) to max - it was reading 5.5 Bar. Pointing to the pressure switch being faulty. Part number BLPS-YKH - quick search on tinternet - and one was ordered, I could have got one quite cheaply from China, but min order was 100, this one has lasted approx 10 years so maybe not 100 of them (mind you if I take any longer building my 4F, I might need them ). Ordered one from Germany being a quater of the price from the only UK stockist, so even with a 20 euro p&p cost, it was still cheaper - should have ordered two tho . Now I just had to wait for it to arrive. Time to watch the tinternet for inspiration. Here is a couple of video's one as on overview and the second for maint. Compressor overview AS 186 maint process So while waiting I follwed the maint process above - mine looked in very good nick. Part arrived, and yes in all the excitment I forgot to take pics. Now a word of warning, this switch works at mains voltage - if indoubt stay well clear. Disconnect from mains before starting - no sh1t sherlock The pressure switch has two wires - yellow and red on my original, brown and blue on the replacement. Mains supply cables are the std European Brown / Blue / Yellow-Green. Oringinal connections were Red & Brown wires twisted together with an insulated crimped cover, the yellow connected to the mains power switch via an insulated crimped spade connector. The yellow wire pulled out of the crimp as I tried to remove the spade connector fron the mains switch. I soldered the blue to the crimp connector - and yes I did remember to fit the insulated boot before fitting the spade connector - oh ye of little faith. The two browns were twisted together soldered and then shrink wrapped. Contrary to the first video hinting at electronics in the compressor, its not that advanced. Essentially, Live to pressure switch, pressure switch to power switch, power switch to motor, motor to neutral. With a choke fitted across the motor to reduce interference - the boss may question on that point. The case is earthed . Now the worrying bit. Power on - I checked for shorts to earth before this and was ok. But to be sure I used a switched socket, and had the compressor power button in the on position before switching on. No fuses blew, the bosses TV viewing was not interupted - possibly a more dangerous outcome than electrocussion . Compressor started up - all looking good. Turned regulator to max. Compressor reached 4.0 bar and switched off - YES!! Now pressed the air brush trigger and watched the pressure fall, as soon as it dropped to 3.0 bar the compressor restarted . Were back to normal. Hope this is useful. Paul
