Pitch on Line Penetrations
Most techs and installers know that drains need to be pitched. I use the rule of thumb that drain lines should generally be pitched 1/4″ per foot of horizontal run. One thing that can easily be forgotten is pitching wall penetrations when drilling. It’s as simple as drilling with a slight upward angle if drilling […]
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It Has a Flat For a Reason
When tightening down a blower wheel or a fan blade on a motor shaft, ONLY tighten it on the flat of the shaft. That flat is machined into the shaft on purpose. It gives the set screw a face to bite into instead of a curve to slide off of. On most residential motors, it […]
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Motor Speed – The Basics
How does a typical single-phase motor know how fast to run? Typical induction motors depend on the electrical cycle rate of the incoming power (measured in hertz) for their speed. Our power in the US makes one complete rotation from positive electrical peak to positive peak 60 times per second, or 60hz (50hz, or 50 […]
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Understanding Relays With the 90-340
Relays can be used for many different control applications, including controlling fans, blowers, other relays, contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck, so we will use it as an example. A relay is just a remotely controlled switch that opens […]
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Heat Doesn’t Rise
We’ve all heard some version of the phrase “heat rises,” but is that really true? First, we need to remember that heat is energy, not matter. Heat is a force, not a thing. While heat may result in changes to matter (stuff), it isn’t matter itself. When we add heat to stuff, the molecules inside […]
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The Basic Residential Maintenance for a Heat Pump / Electric System
I need to warn you… The following list is the actual process we use at the company I own for our typical “standard” residential maintenance. I’m sure you will find some things you do differently. Take it for what it is, and I’m happy to get any feedback you may have. Residential Maintenance: Outside Residential […]
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Technician Head Trash
It’s Friday at 6 PM. The schedule is clear, as far as you can tell. Other guys have been getting cleared right and left, so you call in standby. Five minutes pass. Ten minutes pass. You check in again, and sure as &%$#, there it is! You get sent across town to another call that […]
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Why the New Guy Gets Fewer Callbacks
I was going through a recorded service meeting with the Kalos techs, and Bert shared something that has been rattling around in my head ever since. His team went digging through their callback data looking for patterns, and after stepping back and looking at it, one showed up that nobody expected: The newer techs were […]
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Why is 240V called “Single-Phase”?
Why is it called single-phase 240 when there are two opposing phases (or legs)? I wondered why we called two 120v opposing legs “single-phase 240” for years. Then someone pointed out to me that a typical “single-phase” pole transformer only has one power leg entering and two coming out. That freaked me out. How can […]
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