Digital Zeus™ HVAC Tool & Instruments Journal

We are interested in talking to anyone that has either successfully modified the IR communications loop betweeen the Testo® 523 and it’s printer to include a Palm or other PDA device, or anyone that is currently attempting to make this modification.

You can either respond directly to this post or contact us via email at digital.zeus@yahoo.com - you do not have to disclose your identity if you elect not to.

I know there is at least one technician that successfully made this modification, unfortunately I have lost contact with him as a result of a system crash, so it can be accomplished. Thanks for any input relevant to this topic. 

Testo® 556: First Impressions

I’m new to the boards here and I’m not sure if this is the section I should post this in, so if I’m mistaken, please correct me.
I received the 556-1 wireless kit the recently and today was the first chance that I got to use it. The first machine it saw was a 3 ton coolair split that is having occaisional low pressure lock out problems. I’m the third tech on this call and I have not seen the machine until today so I figure this will be a good opportunity to see what this DRSA is all about.

Right off the bat it’s plain to see that this instrument, yes instrument is not for every job. It is rather bulky ( when in case ) and I can’t see techs climbing up and down ladders and running around mechanical rooms with it on a daily basis. I don’t know about you but I like to travel light and usually only carry a small tool bag. I’ll go back to the truck if I think I need gauges. All of my work is commercial and more often then not the problem is electrical in nature. Besides I think that most of us here can tell if a unit is running okay just by feel alone.

With that in mind I have to say that this is the first set of digital gauges that I have ever used and you know what ? I like them. On the call I was on today first tech says TXV is bad, second tech says unit is under charged and has dirty condenser coil. I check and find 125 foot pipe run, 2 liquid line driers ( one at c/u and one inside a/h ), poor airflow evap and excessive pressure drop at a/h. what the 556 allowed me to do was measure pressures,superheat and sub cooling at both locations record them and download them to my laptop all on site. Gauging up was easy and most important of all, quick. The ability to record and transfer the data gathered is not to be underestimated.

The 556 seems rugged enough for its intended use and was relatively easy to set up initially. The display is clear and easy to read and the backlight worked very well. What a pleasure it was to actually see superheat and subcool values along with pressure without having to stop and consult pt chart and then do calculation. I can see that the accuracy of this instrument is a vast improvement over analog gauges. I can tell you that I checked system with my Y/J manifold and when I disconnected them the low side gauge needle was stuck at 15 psi. They were less then a month old and weren’t dropped that I know of. If I wasn’t convinced before I am now.  

Read More of This Evaluation at HVACPROTech.com®

The Only Professional Technicians Boards with Comparative Instrument Analysis

Everyone - This is exactly what i’m trying to get at. It is s fact of life in most companys that you can’t always get the same tech back to the same call. The variability of readings across different gauges and techs is what I would like to see minimized. I Know that for a purely empirical test of analogs vs digital ( excuse me DRSA’s ) I would absolutely agree that duplicating sensor locations and hose connection locations is rule # 1.

The very reason that i even purchased the 556 was so that i could develop some level of confidence in the readings taken by multiple techs across all types of equipment in sometimes less than optimal conditions. Some techs have $400 multi sensor temp kits, some are using fieldpiece, one kid even showed me where he tucked the tip of his pocket digital thermometer under the suction piping insulation. Add to that the inaccuracy inherent in analogs and we can all see that is time for a change.

Field Applications

Hello everyone – today was the third time i have used the 556. today’s patient was a 80 ton Trane water cooled VAV unit with four compressors, each with single circuit. Age of unit is appx 20 years old. Several of these units have developed leaks and I havn’t found them all yet. I’ve used electronic leak detectors, Halide torches, bubbles and dye. As this is typical of the type of service work most of us encounter I thought it would be a good trial for the 556.

The 556 is rugged and appears well suited to field use. It is very easy and intuitive to use and dare I say fun. What a pleasure it is to watch s/h & s/c readings in real time. Here is a picture of the setup I used before the TESTO arrived.

 I underestimated the time saved and ease of gauging up to equipment.. I attached wired probe to LL line and wireless probe to suction line. I left radio handle inside unit and it broadcasted temp signal to 556 flawlessly. Yesterday I could not get it to read s/h & s/c values. Then I realized that I forgot to enter refrigerant type. After that okay. Here is a picture of both the old way and the new way of checking charge. I like the new way better.

The only place to find hard field data on the diagnostics instruments you use. HVAC PROTech.com® http://www.hvacprotech.com

The Need To Test With Digital Instruments

Today, most oil fired equipment is still being serviced and adjusted with traditional manual combustion efficiency test equipment [wet kits] for field service and seldom is testing done on gas, coal, or wood burning equipment. These kits generally consist of a stack thermometer, draft gauge, wet chemical CO2 gas tester, slide rule and smoke pump. Although this equipment has served the industry well over the years, faster, more accurate, real time flue gas analysis is necessary.

Many service technicians are reluctant to utilize digital instruments; there is a certain comfort in using what we are used to, and in some cases we figure if we don’t know, we cannot be held responsible. Nothing could be further from the truth. Failure to test does not absolve you of liability. Information is power whether it used for you or against you.

With digital equipment many errors with the measurement process are eliminated. Analog measurement errors can be the result of interpolation errors, calibration errors, poor repeatability of the measurement and most importantly not having a procedure in place to consistently repeat the measurement process.

Tuning a system should happen in real time, not “after the fact” with a very highly “averaged” sample. [Each squeeze of a wet kit bulb represents a different snapshot of the flue gas. A traditional test blends all those snapshots together into one reading.]

Only digital analyzers allow you to take real time tests. You cannot do a real time test with a a wet kit; it is physically impossible to take the sample fast enough and do the slide rule calculation.

Today testing is not an option, but rather a necessity on every gas, oil, wood or coal equipment that you might service. The truth is digital instruments are faster, more accurate, more reliable and have a higher repeatability than most analog tools. Digital instruments stay in calibration, allow trending, allow more complex functions and save time. Digital instruments allow data to be recorded and reported without human error, and provide accurate results for you and your customers. Data can be recorded much faster than any technician could ever do the calculations and data can also be recorded whether or not the technician is there to see it [eg. using features like online mode on a Testo® 330]. In most cases, the data is an un-editable record, so what you see is what was measured at the jobsite. Permanent records allow the user to track system changes and determine if the system is operating within the design parameters or if changes have taken place.

The Article above is an excerpt from the Testo® Combustion Applications Guide: For Residential and Light Commercial Appliances [A Measurements Reference for the Advanced Technician]. Authored by Jim Bergmann. Learn more about combustion analysis, combustion analyzers or talk to Jim Bergmann at The Technicians Forum: HVAC PROTech.com® http://www.hvacprotech.com

Applying Dyes

Once it’s determined the system is leaking refrigerant - and the leak is either undetectable or inaccessible - applying the dye is the first step in repairing a leak. A good rule of thumb is putting .04-ounces (1.25 ml) of dye per 7 pounds (3.125kg) of refrigerant or 20 to 30 ounces (887.2 ml) of crankcase oil. For example with incremental dye injectors, two doses would be sufficient for a system containing 60 ounces of oil.

Typically, a return trip is needed after injection because it will take days or maybe even weeks, in the case of slow leaks, for the dye to reach the hole and leak out. A larger leak will be detected in only a few hours after injection.

Electronic sniffers should be combined with dye detection because of situations such as intermittent leakage or wind in outside locations. A dye will confirm the leak visually at a specific location. This confirmation is also invaluable if repair funds must be approved by a company manager for an outside service contractor or equipment purchases.

Intermittent leaking generally occurs when oil or particulate matter plugs a hole temporarily. This is why investigating suspected areas of leakage with a dye as well as electronic sniffing techniques should be used. The dye gives a good historical account of where a leak is intermittently occurring, however an electronic sniffer can indicate if refrigerant is currently leaking from the hole.

Seeing the Dye

UV lights, which are a combination of lamps and projecting lenses that process the light from a flashlight sized container, are used to detect fluorescing dye at a leak’s exit point. High powered lights can detect the smallest traces of dye even in maximum lighting situations such as outdoor sunlight.

Generally, dye inspection lamps produce UV, violet, and/or blue light to detect the dye. Violet or near UV lights cause fluorescence of naphthalimide dyes popularly used in auto and stationary refrigeration systems. Blue light lamps are more universal because they cause fluorescence of naphthalimide and perylene dyes.

Inspection lamps range from LED (light emitting diodes), halogen, fluorescent type black light, to HID (high intensity discharge or sometimes referred to metal halide) bulbs. LED lamps are more popular because they require less power to produce a specific narrow range of wavelengths than other methods. LED’s, which are cool to the touch, produce a range of wavelengths sufficiently narrow so that no filter is needed in the lamp to block wavelengths outside the desired range.

Read the Rest of this Article: http://hvacprotech.forumwise.com/hvacprotech-thread4800.html