The wire of choice for feeders and branch circuits in residential locations is Type NM, non-metallic sheathed cable. It is inexpensive, quick and easy to use, and requires a minimum of tools. But its use is prohibited in sensitive locations, so for industrial, commercial, and even some residential locations, electrical […]
By: David Herres – Variable Frequency Drives (VFD’s), also referred to as Adjustable Speed Drives, are prominent in today’s workplace. They are used in elevator, water pump, high-volume air compressor applications and material-handling systems wherever speed and torque characteristics of AC motors are regulated. In Thomas Edison’s time, the DC […]
Elevators have become an essential feature of most multistory buildings and are no longer limited only to tall buildings. Elevators provide an accessible and easy means of egress for employees and customers. In certain types of buildings elevators are required by the model building codes or Federal law
A common application of multiwire branch circuits as described in section 210.4 is for a 120/240-volt, single-phase system where three wires do the work of four, the two ungrounded conductors sharing a single neutral.In a 20 amp multiwire branch circuit if the two ungrounded conductors each carry 15 amps, some people think the neutral carries 30 amps, or the combined total of the current on each ungrounded conductor.
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