stupified

[canusayinsanity]

I've read some posts where guys have said they rarely ever hook up gauges to units for fear of loosing refer but some of you guys still manage to get your sc and sh readings. How is that ? And if you don't take pressure readings how do you really know whats going on? Is there some trick cause I've never heard of it.

[jayguy]

...Is there some trick cause I've never heard of it.

nope. unless the unit has unit mounted gages (which never seem to be accurate) or unit mounted pressure transducers (which are rarely on the liquid line), i don't see how that would be performed.

[gravity]

I use my digicool ak900. have hoses with ball valves. after i take my readings i close the ball valves, remove both hoses from ports and hook liquid line hose to suction valve and suck it back in. on PM's my company says check temp split. i have seen plenty of units with good deltas but overcharged, undercharged, bad txvs, etc.....

[canusayinsanity]

Gravity I read you jumped into commercial, first time? Welcome to chaos.. Where do you get the ak900, I wouldn't mind seeing it in person at supply house.

[gravity]

Its not all that bad.

We do a lot of RTU's. Very easy to work on because everything is all in one.

I worked on some commercial things when doing residential. It's all the same but more crap packed into one.

It is fun though. Got to replace a 7.5ton compressor in a 15ton split a/c. added some 1-5/8 and 7/8 ball valves with a new suction shell.

You can get the ak900 from trutechtools.com. Enter hvactalk as a code and get 10% off.

[valdelocc]

but some of you guys still manage to get your sc and sh readings. Is there some trick cause I've never heard of it.

yeah there is a trick and all you need is a good thermometer, refrigeration guys do it all the time.

[canusayinsanity]

l've talked to a couple top refer guys and they said its impossible to get your readings unless your getting pressures and line temps. So unless you get your pressure reading I just don't see it happening.

[valdelocc]

l've talked to a couple top refer guys and they said its impossible to get your readings unless your getting pressures and line temps. So unless you get your pressure reading I just don't see it happening.

I think you need to re-examine your definition of "top refer guy"
I had compared both methods and they come within the margin of error, the tricky part is knowing where to measure, there are plenty of thread on the subject, do a little research.

[akelesis]

First off When you go to a job site the last thing you do is put your gauges on. You make sure everything else is running up to par. (visually inspect the unit first) things like belts,filters,coils,fans and of course your electrical components and then if you still have a problem then put ur gauges on. usually when you do put ur gauges on u lose a little refrigerant and of course you gotta put it back,especially in refrigeration. My boss went over this stuff when i first started and i said the same thing, but i get it now why you should never put ur gauges on right away. it takes time but it works a lot better. i dont know if most of you guys will agree with what im saying.

And of course have a few reliable thermometers on you all the time Just like the other guy said.
(yeah there is a trick and all you need is a good thermometer, refrigeration guys do it all the time)-valdelocc

[valdelocc]

The service manuals for some Manitowoc instructs the tech to use the temperature only superheat readings as a way to troubleshoot the ice machines.
think about it, superheated,saturated and subcooled and subcooled saturated and superheated, its all temperatures,just figure where to measure. same thing only different.

[ADillon]

In california (i have heard.. california guys can correct me if i'm wrong) you aren't to attach your gauges to assess charge. You can determine the sat temp by measureing a portion of the coil that you know contains a mixture (refrig changing states) this is easy at the evap but can be tougher at the condenser. The simply compare line temps to sat temps just like if you had checked pressure. I don't do this, I check pressures superheat and subcool and resturn liquid refrigerant back to the system through the low side to prevent loss of charge.

[zartangreen]

First off When you go to a job site the last thing you do is put your gauges on. You make sure everything else is running up to par. (visually inspect the unit first) things like belts,filters,coils,fans and of course your electrical components and then if you still have a problem then put ur gauges on. usually when you do put ur gauges on u lose a little refrigerant and of course you gotta put it back,especially in refrigeration. My boss went over this stuff when i first started and i said the same thing, but i get it now why you should never put ur gauges on right away. it takes time but it works a lot better. i dont know if most of you guys will agree with what im saying.

And of course have a few reliable thermometers on you all the time Just like the other guy said.
(yeah there is a trick and all you need is a good thermometer, refrigeration guys do it all the time)-valdelocc

I agree
i always go end of duct run and get a feel of flow,,

Also good for customer to see also a little show plus effective,,

with these micro channel coils this practice should be standard.

A few times of course didnt have to but did than that schrader just wanted to get lose it knew it was a friday im sure.
t

[Chris_Worthington]

Just a simple question:

If I have hoses with quick connects/ball valves with "X" gas in the hoses and I dump the liquid back in.....

What on average am I losing here?