Types and Classification of Faults on Electrical Power Systems

Question: How many types of faults exist on the power system and how they are classified? Answer: Generally four types of faults exist and are classified into two categories. Symmetrical faults: They give rise to symmetrical equal currents having a displacement of 120°. Unsymmetrical faults: They gave rise to unsymmetrical currents having unequal displacements. List contains: Line to line to line fault Line to ground Line to line Double line to ground Types of Fault Classification Severity of Fault 3 Line Symmetrical Most Dangerous Line to Line Unsymmetrical Fault More Dangerous Line… Read More

Types of MCB/MCCB

  MCB/MCCB are widely used in electrical distribution system for ON/OFF Electrical supply and it also gives over current and short circuit protection. Selection of MCB/MCCB involves technical as well as Mechanical parameters. Not all the parameters are important but careless observation leads to wrong selection of MCB/MCCB or may increase cost unnecessarily. Specifications of MCB/MCCB: Current Related: Frame Size (Inm): Amp Rated current (In/ Ie): Amp Ultimate short circuit breaking capacity (Icu): KA Rated short-circuit breaking capacity (Ics): % of Icu Voltage Related: Rated voltage (Ve): Volt Rated Insulation voltage (Vi):… Read More

Types and accessories of MCB/MCCB

  Utilization category / Characteristic (B, C, D, K, Z curve): Characteristic of Trip curves of MCCB tell about the trip current rating of MCCB. MCB will trip instantaneously according to their Tripping Characteristic at 0.1 sec. There are various type of MCCB: Type B MCCB Type C MCCB Type D MCCB Type K MCCB Type Z MCCB Type B MCCB: Operating Current: This type of MCB trips between 3 and 5 times rated current (In). Operating Time:04 To 13 Sec For example a 10A device will trip at 30-50A. Application: Domestic… Read More

MAX44211 Output Protection

Unwanted transients emanating from the power line back to the line-driver’s output and back-EMF generated by the coupling circuit when the load is disconnected and connected, and vice versa, create undesirable over-voltage conditions. Back-EMF is also generated when the line driver outputs are toggled from high to low impedance state, if significant current was flowing at the disconnect time. The MAX44211 power line communications driver most often is placed facing the power line with an isolating stage between them. In case of such over-stress conditions, external protection is required to protect the… Read More

High-Speed Over-current Detection

This high-speed, low-side over-current detection solution is implemented with a single zero-drift fast-settling amplifier (OPA388) and one high-speed comparator (TLV3201). This circuit is designed for applications that monitor fast current signals and over-current events, such as current detection in motors and power supply units. The OPA388 is selected for its widest bandwidth with ultra-low offset and fast slew rate. These parameters allow the circuit to be a well-balanced, high-speed solution in order to accurately detect high frequency current components. In applications that only require average current detection, devices with less bandwidth can… Read More

Motion Sensing & LED Control

Reference Design Description The Motion Sensing & LED Control Reference Design demonstrates how to use Zilog’s Z8FS040 ZMOTION MCU with the IXYS LDS8710 High-Efficiency LED Driver and explains how to implement features such as ambient light detection and LED dimming in addition to passive infrared motion detection. It also illustrates how the combined capabilities of both products are an exceptional choice for energy management functions in applications ranging from low-power displays and backlighting to ambient room lighting control. Features Integrated passive infrared (PIR) motion sensing and LED control combined in a single… Read More

Portable Variable Power Supply

In many of the project applications and testing applications, Variable DC Power supplies are used. Sometimes it happens that one can not find an AC power socket nearby testing circuit. Also, Power supplies are usually AC powered and are bulky, because of their voltage transformers, to bring anywhere near testing circuit or equipment. Hence, Portable Variable DC Power Supply is required which helps people become mobile in doing electronic projects that will need power supplies. This project uses a voltage regulator and a potentiometer that allows the user to change the output… Read More