New Micron Guage

[Gunslinger]

look at the above picture. Where the micron gage connects, I have a cor remover in line that allows me to isolate the micron gage.

[beachtech]

yours uses a thermocouple instead of a thermistor

[beachtech]

look at the above picture. Where the micron gage connects, I have a cor remover in line that allows me to isolate the micron gage.

unscewring that gauge before charging isnt going to raise you vacuum to an unacceptable level IMO

how low do you go? manu wants 400 and you pull down to 200, i don't think that quickly removing your vacuum gauge is going to put the whole system over 400

[Gunslinger]

does this help?

try this as photo won't enlarge

http://hvac-talk.com/vbb/showthread.php?t=187602

[Tiger93rsl]

Thats A nice setup I really need to make use of that 1/2" port. I'm just waisting too much time evacuating. I have 2- 6 CFM 2 stage pumps I wonder how it would do to use that setup with 2 -6 CFM pumps in parallel.

I just wanted a little input on that yellow jacket guage that was posted. I haven't replaced mine yet. I can get one from johnstone for $210.98 anyone know of a cheeper place?

[beachtech]

i generally can get down and below 200 microns on a split resi unit in less than half hour.

depending on what you're working on, twinning the pumps can hurt you more that it can help you, causing freezing inside the system from pulling down too fast. so i been told.

that isn't a bad price IMO

i always buy locally, that way if i have any troubles, it's thier problem

[Texas-Tech]

Today I ran both 6cfm pumps all day long on a 15 ton split, 2"suction about 120 ft long. When I turned them off I was at 455. We will see in the am what the reading is after setting all night. How much rise would be acceptable and what would it tell me? Could be moisture still in pipe or a small leak,,,,,,,,guess we will see.
The other 3 are finished and held at 500.

[Tiger93rsl]

i generally can get down and below 200 microns on a split resi unit in less than half hour.

depending on what you're working on, twinning the pumps can hurt you more that it can help you, causing freezing inside the system from pulling down too fast. so i been told.

that isn't a bad price IMO

i always buy locally, that way if i have any troubles, it's thier problem

WOW thats impressive. I'm doing this setup, it took me 1 hour the other day (new oil and just overhauled pump) to pull a 400 micron vaccum in a 5 ton packaged water source heat pump useing my 1/4" port . I'm going to make my manifold set up for 2 pumps on big systems.

[Gunslinger]

I pull a vacuum (no cores installed) and purge with N2. Then I pull a vacuum again. I like to see no more raise than 100 after watching the micron gage for 15 minutes. The use of the core removers and N2 make the process much faster.

[Tiger93rsl]

Will a vacuum pull the core back in when it gets deep enough if your O-ring isn't holding tight? And how about useing those core removal tools under a vacuum, you would think those o-rings they use would leak over a short period of time. And I haven't found away to repalce the o-rings in my C&D core tool. Never mind I forgot about the ball valve. Anyhow not to hijack this thread but does anyone know how to replace those O-rings?

[beachtech]

WOW thats impressive. I'm doing this setup, it took me 1 hour the other day (new oil and just overhauled pump) to pull a 400 micron vaccum in a 5 ton packaged water source heat pump useing my 1/4" port . I'm going to make my manifold set up for 2 pumps on big systems.

an hour on that! you coulda been down in the 100's with this set up

i pulled a packeg RTU 7.5 tonner down to 200 in 25 minutes a couple months ago. and it didn't rise above 250 after standing for 20mns.

the compressor was new, so that helped some. virgin oil.

but i also try to get things going with a heat gun, and or make sure the crankcase heater is running too

[beachtech]

Will a vacuum pull the core back in when it gets deep enough if your O-ring isn't holding tight? And how about useing those core removal tools under a vacuum, you would think those o-rings they use would leak over a short period of time. And I haven't found away to repalce the o-rings in my C&D core tool.

they are replacable

i promise

one of mine came ou on me the other day.

[tarheel_tech]

Post 58 on the thread that Beach linked to is a pic of my set up.I try to get below 200 microns everytime I pull a vac.On commercial jobs,I will use two pumps on numorous times.