Tech, Mechanic, or Craftsman
Put three good tradespeople in front of the same problem, and you may see three different kinds of enthusiasm. One wants to understand why the system behaves that way. Another wants to get the failed part out and make the repair. The third is already thinking about the layout, access, and details that will make […]
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Double Lugging, A Common Mistake
Connecting more than one wire on or under a single lug or connection point is called “double lugging,” and it is ONLY allowed in line voltage wiring under one condition, according to NEC 110.14: If the terminal, lug, or connector is specifically rated for more than one wire In the case of a conductor splice, […]
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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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