Easy Motor Repairs

Frequently, a motor will fail to start when powered up after an idle period. It may or may not make an audible hum, or it can trip the overcurrent device. To begin, check to see if there is power and if the guard or a fan blade has become bent so that the fan cannot…

An Essential Skill

A far better way was developed. Solderless connectors (“wire nuts”) make for a more efficient workflow and, if properly deployed, result in quality connections every time. An additional advantage is that for testing or alterations, the wire nut can be removed and replaced easily. Soldering is still essential in electrical work although it is used…

More PCB Repair Techniques

There are other concerns as well. For high-frequency signals, probe capacitance becomes critical, and there is the whole matter of impedance matching so that you do not have a chaotic mix of harmful reflections. There are many variations in the ways that an oscilloscope has to be set up, depending on the make and model…

Frequency Is All-Important

Actually, any conductor has inductance, whether it is an ionized channel blasted across the sky by a lightning bolt or a nerve cell axon within your brain. However, usually we are talking about a segment of copper wire. Winding it to form a coil multiplies the inductance, and if these windings encircle a core made…

hvac-cooling-load-calculation

HEATING AND COOLING LOADS

Heating and Cooling The first step in calculating the heating and cooling loads is to establish the project’s heating design criteria: • Ambient dry-bulb or wet-bulb temperature (or relative humidity), wind direction and speed • Site elevation above sea level, latitude • Space dry-bulb or wet-bulb temperature (or relative humidity), ventilation air • Internal or…