- Tech Tips
In this video we provide an overview of universal digital controls, explain the ERC 213 and install it on a reach in a freezer as well as solve a few more problems along the way.
We live in a world where we often make decisions quickly and we expect to see quick results.
This works on Amazon, I order a new belt and it shows up in two days… like magic.
I start to expect everything to work like that…
Whenever I go to the gym (which isn’t very often) I get frustrated by how long it can take to see results. If I eat one nasty salad, I expect to see my spare tire melt away in an afternoon.
On one hand I know eating right and getting exercise is good for me… on the other hand, it’s annoying and it takes too long so I stop and eat at Sonny’s BBQ.
We can all look around our trade and see TERRIBLE decisions made every day. Bad workmanship, unsafe practices, emotionally driven reactions, unprofessional customer service and the list goes on and on…
I’ve talked before about how Dan Holohan talks about search VS. research in learning. Search being simply looking for a quick answer and research being the study of a topic or practice of a discipline until you really understand it.
The first mindsets is about convenience and expedience and the other is about the long haul, the future benefit.
Deep in each of us is a desire to act according to what is best for ourselves, our families and our careers.
Some would call this “self-interest” a problem. I think it’s actually the key to good decision making.
People acting in their own self-interest is the fuel for all the discovery, innovation, and prosperity that powers the world.
The world needs people who see an opportunity to better themselves, rise to a challenge, make a difference and reap the reward.
This isn’t “selfish” or “entitled” in the negative sense because the things that make us truly happy are good things.
I don’t know about you but I feel best when I treat people well, get a good night sleep and find a way to make the world a better place in one way or another.
The barrier to making “good” decisions isn’t self-interest vs. altruism it’s more about making long-term decisions instead of short-term. It’s about making choices based on informed self-interest rather than on basic emotional reactions or the “tyranny of the urgent”.
Emotional Decision Making
I know this may come as a shock but I’ve lost my cool quite a few times over my career. Thankfully, none of these instances led to any major consequences (that I’m aware of).
On the other hand, I don’t look back at any of those emotional reactions and think “gosh I’m glad that’s how I behaved”.
Informed self-interest teaches you that reacting out of emotion isn’t good for you over the long haul.
I’ve learned that I usually respond with negative emotions when I feel attacked or disrespected. When that happens it’s best for me to back off, give it some time and then come back and address it with a solution in mind rather than emotion.
The Tyranny of the Urgent
My business (Kalos Services) is an HVAC/R, Electrical and General Contracting business. My father is a GC & EC and we started the business together in 2005 with all three disciplines under one roof.
I joke around with my Dad about how demanding construction managers and superintendents can be on subcontractors.
In construction emergencies take precedent over planning and quality work… and EVERYTHING is an emergency
Of course, that’s an exaggeration…. but not by much.
We call this pressure to drop everything and take care of the “emergency” the tyranny of the urgent. Sometimes those emergencies are real and sometimes they are imagined. Either way, when they are forced in our laps we have a decision to make.
In our trade there is a constant tension between production, execution and timelines and quality, safety and general mental health.
Sometimes you do need to “get after it” to get a job done but it can’t be every day and it shouldn’t be at the expense of your long-term health or safety.
A tradesman working with informed self-interest will work hard and efficiently but won’t take foolish risks or give in to the pressure to perform poor quality work.
Often it is this push to get work done in the Summer that leads to service techs who cut corners, end up with a trashed van and paperwork improperly done.
It’s a slippery slope and every company and tech needs to do a reset every now and then and think.
Are you really making the best choices for your business, techs, and customers or are you giving in to a constant emergency mindset.
I have 9 kids with #10 arriving in a few weeks. I love kids, they are great, but they are driven by short-term, uninformed desires. Hunger, anger, fear etc…
These are instincts or urges. We are all born with them and one of the defining characteristics of being an adult is curbing them so that we can make progress in our lives.
As adults, these are everything from addictions, temper, overeating, laziness, and hypochondria.
Usually, we find ways to excuse our behavior to ourselves while everyone around us knows that we are bound by them.
In other words… in order to act in your own real self-interest, in the long run, you need to be able to control what “feels” right in the short term.
The Most Important Choices
I don’t know about you but I really enjoy this trade. I don’t always enjoy the business model or the hours but the work is really interesting.
The most important decisions we can make in our own best interest have to do with things other than air conditioning, these are things like.
So on and so forth…
All of these things are pretty obvious, and All pretty hard to do in our business, especially in the busy season.
They are still all according to the philosophy of informed self-interest. They are all choices you will look back on and feel good about.
You probably won’t feel the same about
I’m NOT saying there is anything wrong with an occasional 70hr work week or some informed risk-taking now and again. The American flag is on the moon because many smart people worked hard and took a TON of well-educated but very real risks.
Thoughtful risk-taking and sacrifice is fine and good… it’s what this country was built on but you need to look back at choices with the eyes of the future and consider if the risk and reward is worth it.
SOMETIMES WE NEED TO PAUSE AND TAKE STOCK
I know it probably sounds like I’m preaching, truth be told, I’m struggling with all these same things right now. This is written to me as much as anyone.
Have a great informed self-interested week.
As we have mentioned in several previous articles, many blended refrigerants have glide, which simply means they boil and condense over a range of temperatures instead of just one temperature.
As an example consider refrigerant R407c, it is a zeotropic blend which means it has enough glide that it makes a big difference if you fail to take it into account.
For example, on an evaporator coil running R407c the refrigerant leaving the TXV will begin boiling at the bubble point, let’s say that the pressure in the evaporator is 80 PSIG that bubble temperature will be 40°.
Now as the refrigerant continues boiling the temperature will begin increasing towards the Dewpoint which is 50.8°. Any temperature gained ABOVE 50.8° on a R407c system at 80 PSIG is superheated, meaning the refrigerant is completely vapor.
So we calculate superheat as temperature above the dew point and subcool as temperature below the bubble point and the condensing temperatures and evaporator temperature aren’t fixed but they GLIDE between the bubble and dew and back again when the refrigerant is changing state.
But what does this mean for evaporator and condensing temperatures when calculating target head pressure (condensing pressure) and suction pressure (evaporator pressure) also known as evaporator TD and condensing temperature over ambient?
The simplest way is to use the midpoint between the dew and bubble points to calculate CTOA and DTD.
In the case above you would simply calculate 50.8° + 40° = 90.8 | 90.8 ÷ 2 = 45.5° average evaporator temperature or midpoint
Emerson points out that evaporators would be better calculated using 40% of bubble and 60% of dew but the extra complexity generally doesn’t make enough difference to mention.
I made this video to demonstrate further
First off, the correct acronym for a GFI (Ground Fault Interrupter) is a GFCI (Ground Fault Circuit Interrupter) and the purpose is to act as a safety device to protect from electrical shock.
GFCIs can be built into outlets, circuit breakers and even extension cords and are generally used for safety in wet environments like bathrooms, kitchens and outside.
A GFCI measures the difference in current between the line (hot) and the neutral. When even a small difference exists between neutral and hot the GFCI trips. This happens because a difference between neutral and hot means that some of the current is “leaking” to ground instead of being carried properly on neutral.
An example would be an electric drill plugged into an outlet outside and the cord plug falls into a mud puddle. If there is no GFCI some of the current will go out of the plug to ground through the puddle, causing hot to carry more current than neutral and making the puddle a potential shock hazard. If the circuit were protected with a GFCI it would trip immediately when the imbalance was detected.
Another nice thing about a GFCI is that it can help protect a circuit that does not have an equipment ground such as tools and appliances with two prong cords or two conductor outlets.
So much of what manufacturers do with modern compressors seeks to make them more efficient with better ability to load match, hopefully without reducing ruggedness. The Copeland Scroll Digital™ or Digital Scroll is one design that has become very popular due to its simplicity and versatility.
But before we go further, let’s define some terms
For years I’ve heard about “axial and radial compliance” from Copeland so let’s define those quickly
These are the forces in line with the axis or center of the scroll, the “up and down” force that holds the stationary top plate together with the oscillating bottom plate.
These are the forces in line with the radius of the scroll plates, the “side to side” forces that keep the two plates in contact with one another.
Copelands definition of compliance – “Compliance” is the ability to separate under abnormal conditions
In other words, the scroll plates are forced together top to bottom (Axial) and side to side (Radial) but if something goes wrong they can separate to help prevent damage.
A Copeland Digital Scroll uses the axial (up and down) compliance to intentionally load (full capacity) and unload the compressor on and off for various periods of time to match compressor capacity to the equipment load.
These digital scrolls have a solenoid that allows fully loaded operation like usual when it’s de-energized and allows for fully unloaded operation when energized. By varying the loaded time to unloaded time the compressor can vary its output over a period of time and provide excellent capacity control. Technicians in the field may hear this loading and unloading and think that something is going wrong because it does SOUND quite unusual to the trained ear.
My brother was working on a large rooftop unit and heard it unloading so he put his ammeter in the compressor and observed and consistent increase and decrease of compressor amperage. Sure enough, it was a Copeland digital scroll.
When I started in the field I was a 17 year old helper with one year of tech school under my belt. In other words…. I knew nothing. As I’ve mentioned before there were a few experienced techs who took me under their wings at different stages, but the most influential was a guy named Dave Barefoot. For whatever reason, Dave decided to share everything he knew and he was exceedingly patient with my mistakes, busting my balls all the way.
Even now I call people smarter than myself like Jim Bergmann, Bill Spohn and Jeremy Smith when I can’t get my head around something. You never grow out of benefitting from helpful people to call when you need an extra brain to work on a problem.
Here is a quick tech tip about finding a mentor from a tech I hired at my previous employer and just recently connected with. Grant “Rusty” Hayes is a smart guy and he benefitted from some of the same great mentors I did when I was coming up. Thanks for writing this Rusty.
The greatest asset I have found early on is finding someone who is willing to teach and asking them to mentor you. This may be common knowledge but I’ve found that many techs hoard their knowledge, or don’t have patience enough to help an unlearned tech.
No matter if the person is a co-worker or not, find someone you can call in a pinch and talk to when you don’t understand something. At the same time cultivate a love for reading especially the installer documents and the material shipped with the units. There is a lot of good information for learning in those documents and will help you learn how that particular system is intended to operate. This will keep you from abusing you mentor with every little thing and you may find you have something valuable to add to the conversation.
Having someone to call to help you without being made to feel your not learning fast enough is valuable and can prevent you from feeling this may not be the profession for you. I would suggest someone who isn’t a co-worker for a mentor only because it will prevent any talk among other techs on something you may never live down if you make a mistake. Trust me, you will make mistakes but never being able to get past the mistake can hinder your confidence and growth. Of all the things I’ve learned, finding someone with a teachers mindset who wants to help others is by far the most valuable tool I’ve used over the years. Don’t lose heart, always learn and grow, in the HVAC profession or whatever you’re doing or want to do. This is the best advice I have for anyone new to the trade or profession. Sometimes the best way to find a mentor is just asking.
Bert (Kalos Tech) and Keiran (Kalos Apprentice) join Bryan in the studio to talk through the basic refrigerant circuit and how it functions. They talk compressor, condenser, metering device and evaporator as well as the four lines and the states of the refrigerant as it travels.