The install manual tells you to ream the end of the tube while it's
pointed downwards (page 17).
http://sanyohvac.com/assets/document..._72_Series.pdf

I would still be worried about getting metal particles inside it.
I was thinking maybe stuff some non-lint fabric up in there,
to block the tube up, and then blow it out with a blast of dry air
from the other end.?.

I have two pipe cutters that I use for cutting copper water tubing.
I think the smaller one might be good for this job. It's pretty sharp.
At work, I use a super fine jeweler's saw and a fixture to cut off
0.141 OD hardline coax cable. That will be my backup method,
if my small tube cutter fails to perform. I can make fixture blocks on my Chinese mill.

The manual says "the ideal (or target) vacuum condition is around 10 mmHg abs."
(What does that equal to? Is that 10 Torr? (10 Torr=10,000 Micron?)..

That MasterCool pump does 75 Microns. Will that do the job??
Mastercool Inc., Vacuum Pumps

Copper is pretty malliable stuff... After you cut off the excess tube from your line set, there may be a bit of a 'burr'. But before you start stuffing things inside the tube, use your flare tool and do a practice flare or two on the line you just cut off. I'd be very surprised if there was any burr after you make a flare.

Probably will not be an issue.


Should work just great... If you have a micron gauge, you'll know for sure it's working great.

But remember to change the vacuum pump oil just before you do a pump-down. By design, vacuum pump oil absorbs atmospheric water.

Even though your vacuum pump has never been used, it's been sitting and absorbing atmospheric water. Change the oil.

My friend, Bruce-the-Pirate bought a two gallon jug of vacuum oil for some kind of low price. Big mistake. Every time he opens the jug, he's introducing more atmospheric water. Personally I would throw the jug away. But he wears an eye patch and will probably use it anyway.

Buy a small one-shot or two-shot bottle and don't open it until you're ready to use it.

I bought a small plastic two-shot bottle, used half of it, capped the bottle tightly back up and left it on the shelf for a couple of weeks. Now the sides are all caved in because the oil has been sucking the moisture out of the air that was trapped inside the bottle. Pretty amazing. You want that kind of oil to be working for you!

Regards,

-AC_Hacker

P.S.: And remember, I'm not an HVAC technician. In fact, I'm just barely a hacker.

I saw this one on Ebay.. JB DV-22N DV-24N Digital Vacuum Micron Gauge with Case - eBay (item 300353500817 end time Oct-09-09 18:03:08 PDT)

Looks like a nice unit.. 20 to 9000 Microns, What do you think?


And, I have a printout of that table right here, but I still didn't know if
I was reading it right.. Until I looked up "Hg" and found it's the
modern chemical symbol for mercury.. LOL!! I'm so forgetful these days!
Or, maybe I never knew that!

I might end up needing to cut off about 4 feet of line-set, and that
tech guy at Ductless HVAC Supply also advised me to practice on
the extra cable. He said after you do about 10 flares, you will likely
do a better job than some AC tech who is in a hurry..


Re: malleable stuff
That tech guy also said I could use a 45 degree flare tool. He said
when you tighten down the nuts real good, it will come down to 37 degs
without a hitch. Just loosen and re-tighten to normal pressure afterwards.
No probleMoe.. I expressed some doubts and he
assured me it works, because the tubing is so malleable..

What do you think?

Yeah, I know you are a hacker like me. But, I also know that a lot of the
Experts I've seen aren't always doing and expert job..

Looks real pretty.

Mine cost me about $137, bought it from a local supplier. If you can get that one for less, you are that much further ahead.

Well, I didn't know about the angles, that's good to know...

I do know that copper is very forgiving.

Best Regards,

-AC_Hacker

Here's a link to the assembly lube I used.

http://refrig.com/Product/Sealants/N...ylog_blue.html

This is the stuff they referred to as 'snot'.

Regards,

-AC_Hacker

I'm just going to ask for it by it's brand name.. :eek:
It looks like just the stuff I need. May have to get it on-line, since
these distributorships don't like selling stuff to DIYers.

Anyways, are your Sanyo flare nuts metric or SAE??
Since I'm thinking of ordering a kit of 3/8 size flare nut crowfeet..

Wow! I've got to read more.. Just found out about the time required to dehydrate your system
takes longer if it's cold out..
Refrigeration Vacuum Pumps

Really shows the need for a good vac meter.

It's 60 here today, so it would take 36 hours! Wow.. Longer than I expected.


How does the HVAC tech do these Mini-Split Install jobs and turn
on the system in just a few hours???

That's why you are doing it yourself...

Regards,

-AC_Hacker

I guess you kinda have to DIY.. Otherwise the labor cost would be more
than the hardware cost!

Reminds me of Solar PV installations.. LOL!

Found a place locally that sells this 2-stage pump..

Robinair 15150 Vacuum Pump, 1.5 CFM, Two Stage, 110V

Robinair 15150, 15300, and 15500 1.5, 3, and 5 CFM VacuMaster Vacuum Pump - on Sale at the Test Equipment Depot

They have a pretty good price, even with the taxes..