POWER FACTOR IMPROVEMENT AND TRANSFORMER LOADING
POWER FACTOR BASICS Power factor for an AC circuit operating with sinusoidal waveform is defined as the cosine angle between…
How to Parallel Current Transformers?
Current Transformer [CT] is used to obtain replica of primary current for use in metering or relaying applications. Though vast…
Adjusting Current Transformer Ratio
Current Transformer [CT] ratio is specified for one turn or one pass of primary conductor through the window of CT.…
COLD LOAD PICKUP IN POWER DISTRIBUTION NETWORKS
When power distribution circuit is re-energized following an extended power outage, new power demand can be higher than pre-outage power…
CHARGING CURRENT IN HIGH VOLTAGE CABLE
Power cables used for transmission and distribution of power have distributed capacitance. Medium and high voltage power cable consists of…
SURGE IMPEDANCE LOADING OF TRANSMISSION LINE
Surge impedance loading [SIL] of a transmission system is the power delivered by a lossless line to a purely resistive…
Difference between Control Power Transformer and Potential Transformer
Control Power Transformer Control power transformers [CPT] are transformers designed to provide control voltage to contactors, starter control panels, solenoids,…
NEUTRAL CURRENT TRANSFORMER APPLIED WITH ELECTRONIC TRIP UNITS
Neutral Current Transformer [NCT] is required for residual ground fault detection and power metering in three-phase four wires systems. Residual…
INCORRECT MOTOR CONTROL CIRCUIT WIRING
Motor control circuits are typically fed from motor phase wiring by tapping phase circuits with control power transformer. This control…
Non-Shielded Medium Voltage Cable
National Electric Code [NEC] 2005 edition and later editions requires shielded medium voltage [MV] cables for all circuits operating above…