Power supply disturbances can cause significant problems in electrical networks, leading to equipment failure, data loss, and reduced lifespan of devices. Below are the main sources of power supply disturbances and effective strategies to mitigate them.
1. Internal Sources of Disturbance
These disturbances originate within the electrical network.
A. Switching Operations
Problem: Switching transformers, capacitors, or circuit breakers can cause transient surges and...
Posted in Design / Protection on January 7th, 2025
Comparison of Tripping Characteristics for Miniature Circuit Breakers (MCBs)
Miniature Circuit Breakers (MCBs) are essential for protecting electrical circuits from overcurrent, short circuits, and faults. The tripping characteristics of MCBs define how quickly they disconnect a circuit based on the type of load and fault current. Different types of MCBs are used depending on the nature of the circuit and its expected inrush currents.
Types of MCBs and Their...
Posted in Design / Protection on January 6th, 2025
Non-Trip Circuit Breakers – Standards, Applications, and Comparisons
1. Comparison of Non-Trip Circuit Breakers vs. Standard Circuit Breakers
1.1 Key Differences in Design and Function
Feature
Non-Trip Circuit Breaker
Standard Circuit Breaker
Automatic Tripping
No (manual intervention required to disconnect)
Yes (trips automatically during faults)
Overcurrent Protection
Not provided by the breaker itself
Provided to protect wiring and devices
Manual Control
Required to disconnect the circuit
Optional (can trip automatically)
Primary Use
Maintenance, diagnostics, critical systems
General protection of circuits from overloads and...
Posted in Design on January 5th, 2025
Trip-Free Circuit Breaker – Definition, Applications and Standards
I. Definition
A trip-free circuit breaker is a type of circuit breaker that cannot be manually held in the "ON" position when an electrical fault occurs. It will automatically trip to interrupt the circuit, regardless of whether the operator is holding the switch in the "ON" position or trying to turn it back on. The breaker will remain in the...
Philippine Electrical Code – Equipment Grounding and Bonding
The 2017 edition of the Philippine Electrical Code (PEC), Part 1, closely aligns with the National Electrical Code (NEC) and provides specific provisions related to equipment grounding and bonding. These provisions ensure that all metal parts of electrical equipment are adequately bonded to prevent electrical shock and enhance overall safety. For detailed guidance, it is advisable to refer to...
Point-on-Wave (PoW) Switching
Definition
Point-on-Wave (PoW) switching is a technique used in power systems to control the precise timing of circuit breaker operations in relation to the waveform of the alternating current (AC) voltage or current. The objective is to minimize electrical transients, mechanical stresses, and other negative effects associated with switching operations.
Application
Random switching of power system equipment can result in high-frequency overvoltage...