#electrical

Tech Tips:

Crankcase Heaters and Single-Pole Contactors
By:Bryan Orr We keep two-pole, 40-amp 24v coil contactors on all of our vans. They are versatile and reliable, and you can replace most residential A/C contactors with them. There are a few things to watch for, though, especially when you have a crankcase heater. Many brands power the crankcase heater constantly and shut it […]
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Short Circuits
The term “short” has become a meaningless phrase in common culture to mean “anything wrong with an electrical device.” A short circuit is a particular fault that can mean one of two things in technical lingo: 1. Any two circuits that are connecting in an undesigned manner This issue would be the case if a […]
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An Electric Heat Mistake
I started working as a tech when I was 17 years old, fresh out of trade school. My first winter out on my own, I went to a service call in an older part of Orlando, a part of town I had never worked in before. It was an especially cold winter that year, and […]
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Isolation Diagnosis
There are many great diagnostic tools available to the service technician today, but I haven't found a tool as versatile as the simple isolation diagnosis. There are many ways this concept can be applied, but let's start with some examples so that you get what I mean. Low Voltage Short Circuit Isolation Diagnosis You arrive […]
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Strip Control Wires Properly
Erich Vinson is a tech from Colorado and one of the most entertaining people I interact with online. He wrote this quick tech tip on stripping back the outer jacket properly on control wires, and it happens to also be something I preach. Thanks, Erich. In the first picture (above), you can see what happens […]
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Grounding and Bonding Myths
By:Bryan Orr Grounding is an area of many myths and legends in both the electrical and HVAC fields. This is a short article, and we will briefly cover only a few common myths. For a more detailed explanation, I advise subscribing to Mike Holt's YouTube Channel HERE. Myth – Current Goes to Ground Actually, current […]
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Start Capacitor & Inrush, Facts & Myths – Part #4
By:Bryan Orr Now is the part where we get specific about start capacitors and inrush. If you haven't read the first three parts, please do so before reading this one, or it may not make sense. (You can find Part #1, Part #2, and Part #3 at these links.) I'm going to come out and […]
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Commercial Contactor Considerations
This tip was created by Jason Pinzak and originally posted on the HVAC Technician's Facebook group. It is reposted here with permission from Jason. Thanks! Contactors are useful in commercial and industrial applications, particularly for controlling large lighting loads and motors. One of their hallmarks is reliability. However, like any other device, they are not […]
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Multimeter Categories
Testo 760 Category IV Multimeter I was standing at a booth at the HVAC Excellence Educators conference, and an instructor walks up, grabs a meter, and asks me, “What's the difference between a category 3 and a category 4 meter?” Well, I really wasn't sure, but I knew that the category 4 meter is rated […]
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