What is in your toolbox?
Test & Measurements
When I worked as a technician I wanted to have every possible tool I would ever need to complete any job I was faced with in my possession (meaning in my service van), including the 2 a.m. emergency calls. While that is a completely unrealistic goal, it did not diminish my love affair with tools. I would have to say that at least 90 per cent of the technicians I have worked with over the years had the same general love affair with tools. Not only do you need the latest new gadget, it is also prudent to have backups for all of the important tools. So, several sets of gauges, a volt meter with a backup or two, an amp meter with a backup or two, a temperature meter with a backup or two. You get the picture.
For the sake of practicality let’s momentarily put aside that type of tool buying mentality and take a look at a comprehensive list of tools that every technician should have in his or her “first response” tool container. I say container because every technician has a preference for what they use to keep their tools in.
At one extreme there is the technician who keeps his tools in a five-gallon plastic bucket – no organization, no structure, just thrown in when the job is finished. Good luck finding anything in a timely manner on the next job. You have to wonder how much lost productivity occurs over the course of a year just searching for that elusive pair of needle nose pliers when they are needed.
Now, if the proper accessory bag accompanies the five-gallon bucket, it can become a very nice receptacle for organizing your tools. And while the “accessory bag” costs a few dollars, the bucket is relatively inexpensive (see Figure 1).
There are some technicians who use toolboxes. These may contain tools in an organized fashion, or something close to the disorganized five-gallon bucket system, but a toolbox certainly projects a classier look than a bucket, which is important to some.
Or, a technician might use one of several styles of pouches, which while offering the ability to organize, they can be a little limited in size and tool selection (see Figure 2).
Then you have technicians like me, who are absolutely fanatical about order. I once had a co-worker who spent much of his free time hunting, fishing and practicing to be a mountain man. He was quite good at leatherwork and had made himself a really nice leather bag for his tools. It was made of thick cowhide, measured about 12″ x 20″ x 10″ deep, and had several large pockets for things such as flare caps, electrical tape, wire nuts, and so on. It also contained about a dozen or so smaller pockets for screwdrivers, wrenches, nut drivers, etc. To top it off, he made sure to include nice thick leather handles to support the weight of the tools in the bag.
It was not too long after his new leather bag made its proud debut at work that he started receiving requests from his coworkers to make them a similar one. It took a lot of persuasion to get him to say yes, but after several months he agreed. I loved that bag, as it had a place for everything I needed and it allowed easy access to it all.
While that bag is long gone, the commercially available bags shown in Figure 3 are somewhat similar. As you can see, there are plenty of pockets for individual items, allowing for a very well stocked and organized “first response” tool set.
So, what should be included? Well, everyone will have his or her own preference as to what should be included. My priority was to have most of what I would need to troubleshoot a problem and perform the necessary repairs without having to constantly run out to my service van for additional tools. That being said, in Table 1 I have divided the items into two categories: essential and optional.
Of course, each technician will have a different idea on what is the best assortment of tools for their bucket/toolbox/pouch/bag/caddy, or whatever. Depending on the size, there are certainly a few other items that could be included. This is one advantage of the bucket – it has plenty of room.
How often do you need your small cordless driver with a Phillips bit or small drill bit to perform some minor job? Or to remove the dozen or so sheet screws holding a panel in place on a rooftop unit, which needs to be removed prior to troubleshooting? How nice to be able to pull out your cordless driver, insert a 5/16″ magnetic bit, and remove them all in a matter of seconds?
Now, if you have the desire to include your cordless driver in with the first response mix of tools, then you will also need a decent assortment of bits (see Figure 4). This includes standard (drill, hex, Phillips) and accessory bits (extended length screwdriver bits, extensions, star, square and allen, adaptor to 3/8″ sockets, and so on).
While not something that is used on a daily basis, the wrench shown in Figure 5 simplifies removing a TEV element. The jaws are relatively thin, which allows them to fit onto the wrench flats of the element without coming into contact with the valve body. It also has a wide opening.
Now, on to some interesting new technology toys that are drawing interest from technicians everywhere.
There is nothing more frustrating than working in an attic or dark machine room and not being able to see what you are doing. In years past you would have a standard flashlight or drop cord to assist. Not any longer. There seems to be no end to lighting accessories to assist today’s technician (see Figure 6). Here are just a few examples: A magnetic flashlight with a flexible head, which should be able to supply light to any obscure location as long as there is a metal surface to attach it to. There is also a wide assortment of LED outfitted head lights.
Every now and then you have a situation that requires you to view something in a very hard to find location. I recall a supermarket where intermittent alarms were happening, and there was never an actual system problem that would have generated the alarm. A rat had chewed the insulation off of the alarm wires in a very inaccessible place. Occasionally they would touch and initiate an alarm.
It took forever to locate this cause. How nice it would have been to have a device that could have assisted with the wiring inspection. Advancements in digital circuitry and video technology have made instruments, which allow for inspecting remote areas, relatively inexpensive. The instrument shown in Figure 7 can view up to 32′ from the handheld device on a 3.5″ screen, and can capture the data in jpeg or video format.
While many larger systems will be equipped with a liquid sight glass, it is typically located at the receiver outlet. Now and then situations occur, due to extreme pressure drop, piping issues, marginal refrigerant charge, which can result in inadequate supply of liquid refrigerant at the TEV inlet. Without a liquid sight glass at the TEV inlet this may be difficult to diagnose. Enter the electronic sight glass. Using ultrasonic sensors, the instrument can sense differences in density in the fluid flowing through the refrigerant tubing. So, small pockets of vapour in a liquid line would stand out as a different density and be sensed by the instrument. Likewise, small pockets of liquid in the suction line would also stand out as a different density. The instrument can assist in troubleshooting lack of liquid refrigerant issues.
Motor bearings have a limited life, and at some point will begin to fail. As the bearing temperature starts to increase, the bearing lubricant will break down. Eventually the motor windings can overheat. The bearings can further degrade and cause a complete motor lock up. Thermal imaging instruments, such as those shown in Figure 8, can assist in analyzing motor bearings as they are beginning to fail by capturing two dimensional infrared maps of the bearing and motor housing temperatures. A process of comparing current operating temperatures to estab
lished benchmark temperatures can detect potential failures before they happen.
While it could be the subject of a complete article, it bears mention that there are several versions of digital manifolds available. Not only are these instruments capable of electronic measurement of pressure and temperature, but they can calculate superheat and subcooling for a multitude of refrigerants. And that is just the beginning.
The instrument shown in Figure 9 takes that concept a step further and can function as a true system performance analyzer. In addition to measuring the actual pressure and temperature points, when a system application is profiled it will also provide what those pressure and temperature points should be for the specific application. This platform can also measure airflow, total heat, sensible heat and latent heat capacity, system capacity in Btuh or tons, and after inputting volt and amp data it can calculate EER and COP, all of which is displayable on your mobile device via the manufacturer’s app.
The basis for an accurate diagnosis of a system problem is having a thorough understanding of system operation as a foundation. With that understanding, information is required to then make the diagnosis. It goes without saying, the more accurate and complete the information, the better a technician is able to make a complete diagnosis. Once the cause of the problem is isolated, the proper tool for the job will make the repair happen more efficiently.
Dave Demma holds a degree in refrigeration engineering and worked as a journeyman refrigeration technician before moving into the manufacturing sector where he regularly trains contractor and engineering groups. He can be reached at firstname.lastname@example.org.
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May 11, 2022