John A. DeDad

Articles by John A. DeDad
The Basics of Autotransformers 4
An autotransformer is a transformer having part of its winding included in both the input and output circuit.
Testing Contact Quality on Live Motor Starters
This unique millivolt testing technique provides a basic check in troubleshooting motor breakdown situations.As a maintenance electrician, I'm sure you've
Get Real About Project Scheduling
Not only are realistic project schedules useful to you during the preconstruction stage, they're also vital to successfully coordinating the day-to-day
The basics of insulation resistance
One of the most fundamental of electrical installation and maintenance tasks is taking insulation resistance (JR) readings. This is done to verify the
Insulation resistance testing: How and why?
This basic electrical maintenance and troubleshooting test can help you diagnose potential insulation problems and reasonably predict when they will occur.How
The Basics of Insulation Resistance Testing 6
How significant is insulation resistance testing? Since 80% of electrical maintenance and testing involves evaluating insulation integrity, the answer is "very important."
Don't Take Chances with Your Life
Proper use of safety equipment on energized and de-energized circuits just might save your life.
Reality of Nostalgia
Recently, I was going through my electrical belongings and ran across some old “friends.” They brought back many memories of when I began working in the
Do Today's Electrical Measurements Leave You Dazed and Confused?
Modern test and measurement instruments go from simple DMMs to handheld oscilloscopes to very sophisticated spectrum and harmonic analyzers.
The Pros and Cons of Proof-Testing
The secret to not damaging old, in-service cable is to apply the maximum test voltage in small increments and closely monitor the behavior of leakage current.
Basic short-circuit current calculation 1
A basic electrical theorem says the amount of current that will flow through a short circuit depends on two variable values: The system voltage and the
The basics of transformers, part 2.
Copper losses in both primary and secondary windings, and core losses are converted into heat in a transformer. These losses are all measured in watts.
Using Your DMM and Scope Wisely
Here's a primer on symbology, terminology, connections, and operation for modern digital multimeters and oscilloscopes.
The basics of transformers - Part 1
A transformer is an energy coupling device that takes electrical energy at one voltage (from its source) and transforms it to another voltage. The new
Using single-phase transformers to create 3-phase systems.
Many older industrial facilities use single-phase, oil-filled transformers made for pole-mounting but installed at ground level to create 3-phase power
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Arlington: 8" by 10" TV Box™

Our new TVB810 TV Box™ delivers the ultimate in versatility for installing wall-mounted TVs in retrofit projects. There's more room in the box for wires; plus, you can install it horizontally or vertically to ensure proper positioning of low voltage connections behind the TV....More

 

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