15 replies to this topic

[tommytech]

The company i work for is pushing hard for all tech's to purchase these gauges,but i dont have experience with the digitals,anyone use these? seem pricey at 350 bucks.

[kdog]

Cool to have, but not necessary - good old dial guages are just fine

[RegUS_PatOff]

- good old dial guages are just fine

just like analog meters ..
sometimes nice to have to see surges, etc.. and to see micro switch transitions ..

[Cactus Bob]

Never happen with me , bought my everyday yellow jackets in 1976

I am 'suspect' of any tec that needs electronic gauges to do his work

[tommytech]

i feel the same way,my yellowjackets have served me well.it may become mandatory to have a set of these here,probably cause too many tech's dont grasp subcooling or superheat.i understand these digi's display that info for you,as well as total amount of refrigerant .

[dbirkett]

I just use analog, don't have to worry about a little water, have a separate temp meter and p/t chart to do superheat/subcool

[atcherservice]

I as well as several of my techs use the Testo 550 has all the refrigerant types of super heat/ subcool and evap temp. The gauges help you raise your game and a tool that will allow you do better diagnostics. I also have the Fieldpiece Version that has a micron gauge built into it helps confirm leaks as well as moisture in the system

ThanksKen

[nickfixit]

If the "company" want you to use them, then the "company" should buy them for you. They could probably get a nice price break buying multipe sets from a supply house.

[Bullstok]

I am 'suspect' of any tec that needs electronic gauges to do his work

Yep. This type of thing allows companies to hire PCM's at a low pay rate without the embarrassment involved when its discovered they don't know wtf they are doing. Training the person correctly takes a lot time and $$ and the investment ultimately goes to the person, then they can do with it what they want (like ask for a raise or go to a different company.) On the other hand, minimal training and advanced tools that do the thinking limit the problems in the field, keeps the tech under wraps, and with a smaller investment in the tech.

I know this does not apply universally, don't get in a knot

Edited by Bullstok, 22 October 2012 - 06:27 PM.

[tommytech]

got two chanced of my employer supplying tools - slim and none. just the way it goes

[suampman]

What is this superheat/supercool you speak of? I do not work on the sealed systems but am interested.

[kdog]

Defines the current state of the refrigerant within the system - superheated is when the temperature of the compound is actually higher than it's boiling point relative to it's pressure (ie boiling water above 120 degrees at sea level) - sub cooled would be ice that measures below zero (freezing point) - it takes much more energy transfer to cause a temperature change in a saturated (boiling/freezing) substance than it does when the temperature is changed otherwise 9water from 40 to 50 degrees).

Example: it require One British thermal Unit (BTU) to cause One Pound of Water to change One Degree Farenheit, so long as it is between 32 and 212 degrees, at that point - 970 BTU's must be added/subtracted to cause the Water (Stem/Ice) to change One Degree Farenheit.

If you were looking at the pressure at these points, you could measure the tubing etc with a thermometer to calculate the difference.

the Term is applied to locations within the system where you want to guarantee the substance is complete gas or liquid. (Evaporator inlet/outlet, Condenser outlet etc)

[suampman]

Thank you Kdog for the explanation. So at saturation it takes immense amount of heating or cooling or pressure change to raise or lower the temp, and by taking the temp at different places on the sealed system you could calculate the pressure at that point in the system. Is that correct? Or should I just steer clear of sealed systems? Either way I thank you for the response.

[certified tech group 51]

For domestic sealed systems and some commercial units, all of the calculations have been figured out a 100 years ago....... Kdog,s explanation is one of the reasons when they tell you to add 5 oz. of refrigerant , they mean 5 oz.......(wait till you really over charge a system, darn electronic scale )....... A sealed system repair is a way to make some good money, If done the correct way.............

[kdog]

It is important to understand superheat when it comes to commercial regrigeration (not so much for domestic) as many controls actually operate from the effect of superheat. Often a sensing bulb is attached to the pipe at some point to switch upon the sensing of superheat. Important to attach the bulb to the top of the pipe as opposed to the bottom.

[atcherservice]

Attach the bulb at 10 or 2 on top or 4 &6 on the bottom