Mch6

[h90]

I am now proud owner of an MCH-6 compressor (it will need 2 month till I have it finally in my hands).
I just read the guide and a few points are raising questions:

1. (1.10.1, page 18): After the first 5 hours or running:
Tightening the torque values
The table shows tightening torques for bolts or hexagonal-head screws........
Question: Do I need to buy the tool to tightening them to the exact torques??

2. Filling a tank: Don't I need to get the non filtered air out of the hose first?

3. Change Oil: every 50 hours. I read somewhere else that it should be every 25 hours???

4. Filter replacement:
Example: 30 Degree C (86 F) Filter duration 20 hours.
N bottles 15 liter 200 bar if the compressor runs at 80l/min 32, if runs at 100 l/min: 40.
that sounds strange! Mine is running at 80 l/min. In my opinion it must be the same amount of air no matter how fast it runs. So the time must be longer with 80 l/min than with 100 l/min

5. Connection: 220 Volt 50 Hz+Earth: here there is no earth connection. All the house doesn't has them. there is no garden I can ram in a rod and even the water pipes are pvc so I can't abuse them. That shouldn't be a problem unless I touch it when it is pluged in, or?

6. What's the best oil to get for it? The guide mentioned that everytime you change the oil, the oil filter must be changed as well. In my understanding that compressor doesn't has an oil filter, or?

 

[emoreira]

5. Connection: 220 Volt 50 Hz+Earth: here there is no earth connection. All the house doesn't has them. there is no garden I can ram in a rod and even the water pipes are pvc so I can't abuse them. That shouldn't be a problem unless I touch it when it is pluged in, or?

Too bad that there is no ground connection in the whole house.
If the electric circuit is correctly isolated from the metal frame of the compressor, there should be no problem, how ever, a safe ground is the best way to avoid shocks.
Try not to touch the compressor running with bare foot or wet.

 

[Peter_C]

The filter mounted in the machine is small and will fail quickly. A secondary one would be a nice upgrade although expensive. Non filter air? Don't worry about. I would run the compressor if it is brand new for a little bit just free air to break it in though. Differ to the instructions.

For oil I would just start it right off with Nuvair 455 from the get go. Drain it and refill it before ever hitting the start button. That way you can continuous blend nitrox at any time in the future...or from the get go. A nitrox stick is around a $100 to build. The Oxyhacker guide covers it well.

No ground? Make one!

 

[h90]

The filter mounted in the machine is small and will fail quickly. A secondary one would be a nice upgrade although expensive. Non filter air? Don't worry about. I would run the compressor if it is brand new for a little bit just free air to break it in though. Differ to the instructions.

For oil I would just start it right off with Nuvair 455 from the get go. Drain it and refill it before ever hitting the start button. That way you can continuous blend nitrox at any time in the future...or from the get go. A nitrox stick is around a $100 to build. The Oxyhacker guide covers it well.

No ground? Make one!

For a second filter: I thought about that already....Checking ebay if I get something old and cheap.
Run in compressor: yes I also thought so.
A Nitrox Stick for around 100$? Do you have more information about that?
thanks!

 

[rjack321]

Make your own nitrox stick for more like $10
Vance Harlow's OXYGEN HACKER'S COMPANION From AIrspeed Press

Change that tiny on compressor filter every 10hrs, there's NO way its good for 20 hrs at 30C.

 

[h90]

Make your own nitrox stick for more like $10
Vance Harlow's OXYGEN HACKER'S COMPANION From AIrspeed Press

Change that tiny on compressor filter every 10hrs, there's NO way its good for 20 hrs at 30C.

the excel file from scubaengineer.com gives that filter in my condition only 3.19 hours because there are just 25 gram Molecular Sieve in it
Might be smart to buy a bigger filter.....

 

[rcontrera]

I am now proud owner of an MCH-6 compressor (it will need 2 month till I have it finally in my hands).

I don't know where you are purchasing it from, but that is an awfully long time!

To answer a couple of your questions, change the oil every 25 hours using high grade synthetic oil. We use either the 455 for Nitrox systems or air conditioned spaces or else 751 for air or for warm areas (the 455 is rather thin in hot areas).

If your compressor dealer doesn't upgrade the machine as they get it from Coltri, put a pressure maintaining valve between the filter chamber and the hose. I also suggest that you install an hour meter on the motor so you know just how long it has run since last service.

When it is time to replace the filter cartridge, use the LF cartridge and you will get a little more life since they have a thinner wall than the original black cartridges and hold a little more desiccant. A lot of dealers say that you can get 3300 cubic feet from a cartridge. But I have found that, at least here in the Northwestern US, we only get between 25 and 30 fills per cartridge.

At least every six months, check the tightness of all the fittings and mounting hardware. Vibration from operation can loosen stuff up and make a gawd awful racket when they let things rattle ... not to mention how much damage it can do.

 

[h90]

I don't know where you are purchasing it from, but that is an awfully long time!

To answer a couple of your questions, change the oil every 25 hours using high grade synthetic oil. We use either the 455 for Nitrox systems or air conditioned spaces or else 751 for air or for warm areas (the 455 is rather thin in hot areas).

If your compressor dealer doesn't upgrade the machine as they get it from Coltri, put a pressure maintaining valve between the filter chamber and the hose. I also suggest that you install an hour meter on the motor so you know just how long it has run since last service.

When it is time to replace the filter cartridge, use the LF cartridge and you will get a little more life since they have a thinner wall than the original black cartridges and hold a little more desiccant. A lot of dealers say that you can get 3300 cubic feet from a cartridge. But I have found that, at least here in the Northwestern US, we only get between 25 and 30 fills per cartridge.

At least every six months, check the tightness of all the fittings and mounting hardware. Vibration from operation can loosen stuff up and make a gawd awful racket when they let things rattle ... not to mention how much damage it can do.

thank you for your answer.
The awfully long time is because I am located in Thailand, and purchase it in Austria. In Austria it was delivered in 10 days. My company is getting seafreight regularly and the compressor stays there in Europe until we get the next seafreight. So it will stay there for the next 1-2 month and than it is 1 month on the ship.
Reason why I do that: The local coltri dealer is really bad (they are also doing Mares and I had real bad experiences with them) as that much more expensive that I can easily accept not having any warranty on it here.

Thanks for the advise on the oil! I plan to run it in aircondition, but most probably still 25-28 degree Celcius.
Thanks for the advise of the pressure maintaining valve! I actually bought already: "Priority Valve "211"" including fittings from your webpage.

That tightening the screws on the cylinder as told in the manual: is that necessary??, as I don't have the tool to measure the torque.

 

[rcontrera]

Sorry you have had a bad experience with your local dealer but glad you figured a work around to get what you need.

I have a tech that is anal about using a torque wrench on just about everything. the other end, I am an old school guy where the torque is to "umphs" on a hand held allen wrench.

It is important to check the screw tightness since vibration can loosen fittings a bit. That can result in leaking gaskets and eventual compressor failure.

 

[h90]

Sorry you have had a bad experience with your local dealer but glad you figured a work around to get what you need.

I have a tech that is anal about using a torque wrench on just about everything. the other end, I am an old school guy where the torque is to "umphs" on a hand held allen wrench.

It is important to check the screw tightness since vibration can loosen fittings a bit. That can result in leaking gaskets and eventual compressor failure.

Well everything has its bright sides.....wouldn't the dealer so bad, I wouldn't have checked the prices in Europe and would have paid a lot more

OK, I'll check the screws without torque wrench. I am also the old school guy, but thought it might be super sensitive on the torque....

I can't await to play with my new toy