# \#protection **URL:** https://forumautomation.com/tag/protection/87.md [Latest](https://forumautomation.com/latest.md) · [Categories](https://forumautomation.com/categories.md) · [Tags](https://forumautomation.com/tags.md) --- ## [Busbar Differential Protection (87B) in Substations](https://forumautomation.com/t/busbar-differential-protection-87b-in-substations/14555)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 30, 2026, 9:08am UTC](https://forumautomation.com/t/busbar-differential-protection-87b-in-substations/14555 "2026-10-30T09:08:24Z")
Busbar differential protection (ANSI 87B) is a high-speed protection scheme used to detect and isolate internal faults within a defined substation busbar zone. It operates by comparing the vector sum of CT secondary curr… --- ## [Which protective device detects gas accumulation caused by internal faults in a conservator-type oil-immersed transformer?](https://forumautomation.com/t/which-protective-device-detects-gas-accumulation-caused-by-internal-faults-in-a-conservator-type-oil-immersed-transformer/14547)
**Author:** [@TSRS](https://forumautomation.com/u/TSRS)\ **Replies:** 1\ **Last updated:** [October 27, 2026, 1:21pm UTC](https://forumautomation.com/t/which-protective-device-detects-gas-accumulation-caused-by-internal-faults-in-a-conservator-type-oil-immersed-transformer/14547 "2026-10-27T13:21:36Z")
Which protective device detects gas accumulation caused by internal faults in a conservator-type oil-immersed transformer? --- ## [What is a Single-Line-to-Ground (SLG) Fault?](https://forumautomation.com/t/what-is-a-single-line-to-ground-slg-fault/14294)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [July 31, 2026, 2:08pm UTC](https://forumautomation.com/t/what-is-a-single-line-to-ground-slg-fault/14294 "2026-07-31T14:08:16Z")
What is a Single-Line-to-Ground (SLG) Fault? A Single-Line-to-Ground (SLG) fault occurs when one phase conductor accidentally comes into contact with the ground or an earthed object. It is the most common type of fault … --- ## [Why do we need Fuse and How does it Work?](https://forumautomation.com/t/why-do-we-need-fuse-and-how-does-it-work/6547)
**Author:** [@ashlin](https://forumautomation.com/u/ashlin)\ **Replies:** 0\ **Last updated:** [June 13, 2019, 5:41pm UTC](https://forumautomation.com/t/why-do-we-need-fuse-and-how-does-it-work/6547 "2019-06-13T17:41:52Z")
WHAT IS A FUSE? A fuse is an overcurrent protecting device it is a small piece of metal which is connected between two terminals and it would be mounted on the insulator base it is connected in series with the circuit o… --- ## [What Capacitor Bank Size is required for a 2500 kVA Transformer?](https://forumautomation.com/t/what-capacitor-bank-size-is-required-for-a-2500-kva-transformer/14214)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [June 25, 2026, 11:20am UTC](https://forumautomation.com/t/what-capacitor-bank-size-is-required-for-a-2500-kva-transformer/14214 "2026-06-25T11:20:07Z")
A properly designed capacitor bank is essential for improving power factor, reducing reactive power demand, minimizing system losses, and optimizing transformer capacity utilization. For a 2500 kVA transformer operat… --- ## [Current Transformer - Ratio Test](https://forumautomation.com/t/current-transformer-ratio-test/14210)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [June 23, 2026, 10:04am UTC](https://forumautomation.com/t/current-transformer-ratio-test/14210 "2026-06-23T10:04:16Z")
Current Transformer - Ratio Test Current Transformer (CT) Ratio Test is a fundamental commissioning and maintenance test used to verify that the actual transformation ratio of a current transformer matches its rated rati… --- ## [MCB: Symbols Decoding](https://forumautomation.com/t/mcb-symbols-decoding/13807)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [January 1, 2026, 1:02pm UTC](https://forumautomation.com/t/mcb-symbols-decoding/13807 "2026-01-01T13:02:11Z")
MCB: Symbols Decoding A simple visual reference to interpreting the codes on a miniature circuit breaker (MCB). Key details include: Brand Name: Schneider Electric Model: C60A Current Rating: 40A Trip Curve: Type… --- ## [What is an SVG?](https://forumautomation.com/t/what-is-an-svg/14201)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [June 18, 2026, 5:39pm UTC](https://forumautomation.com/t/what-is-an-svg/14201 "2026-06-18T17:39:04Z")
What is an SVG? A Static VAR Generator (SVG) is an IGBT-based power electronic device that provides instant reactive power compensation to maintain voltage stability and improve power factor. When system voltage drops, … --- ## [How does Differential Protection work in Transformer?](https://forumautomation.com/t/how-does-differential-protection-work-in-transformer/12911)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [December 19, 2024, 3:24pm UTC](https://forumautomation.com/t/how-does-differential-protection-work-in-transformer/12911 "2024-12-19T15:24:20Z")
Working Principle of Transformer Differential Protection The current entering the transformer = The current leaving it (in normal conditions). When a fault occurs inside the transformer, this balance is disrupted, … --- ## [MCB Protection Curves](https://forumautomation.com/t/mcb-protection-curves/11606)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [November 20, 2023, 11:47am UTC](https://forumautomation.com/t/mcb-protection-curves/11606 "2023-11-20T11:47:46Z")
Electrical protection devices known as Miniature Circuit Breakers (MCBs) have unique curves that show how they react to different overcurrent levels. These curves assist in determining the speed an MCB can trip as a … --- ## [Is it possible to operate earthing and arrester together?](https://forumautomation.com/t/is-it-possible-to-operate-earthing-and-arrester-together/9656)
**Author:** [@instrumentationtechi](https://forumautomation.com/u/instrumentationtechi)\ **Replies:** 1\ **Last updated:** [July 27, 2021, 3:45am UTC](https://forumautomation.com/t/is-it-possible-to-operate-earthing-and-arrester-together/9656 "2021-07-27T03:45:23Z")
Can arrester and earthing work together --- ## [Can a surge arrester reduce third harmonics?](https://forumautomation.com/t/can-a-surge-arrester-reduce-third-harmonics/12302)
**Author:** [@automation\_engineer6](https://forumautomation.com/u/automation_engineer6)\ **Replies:** 1\ **Last updated:** [October 2, 2024, 4:39pm UTC](https://forumautomation.com/t/can-a-surge-arrester-reduce-third-harmonics/12302 "2024-10-02T16:39:21Z")
Can a surge arrester reduce third harmonics? --- ## [ANALOG SIGNAL ISOLATION AND ITS ADVANTAGES](https://forumautomation.com/t/analog-signal-isolation-and-its-advantages/6151)
**Author:** [@ashlin](https://forumautomation.com/u/ashlin)\ **Replies:** 0\ **Last updated:** [March 27, 2019, 4:57pm UTC](https://forumautomation.com/t/analog-signal-isolation-and-its-advantages/6151 "2019-03-27T16:57:05Z")
The main reason for signal isolation is to provide electrical isolation between the input and the output signal. isolation of analog signals is very important for industrial automation and medical applications. The isola… --- ## [What is the Difference between AC Ground and DC Ground?](https://forumautomation.com/t/what-is-the-difference-between-ac-ground-and-dc-ground/13769)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [December 11, 2025, 11:40am UTC](https://forumautomation.com/t/what-is-the-difference-between-ac-ground-and-dc-ground/13769 "2025-12-11T11:40:29Z")
What is the Difference between AC Ground and DC Ground? Understanding the difference between AC Ground and DC Ground is essential for designing a safe and dependable electrical system. AC Ground AC Ground used mostly fo… --- ## [Understanding the Two Essential Types of Grounding: PE vs. FE](https://forumautomation.com/t/understanding-the-two-essential-types-of-grounding-pe-vs-fe/13762)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [December 8, 2025, 9:54am UTC](https://forumautomation.com/t/understanding-the-two-essential-types-of-grounding-pe-vs-fe/13762 "2025-12-08T09:54:48Z")
\[color=#ff0000\] Understanding the Two Essential Types of Grounding: PE vs. FE\[/color\] In electrical engineering, \[color=#1E00A3\] “grounding” \[/color\] is a fundamental concept but it performs two different principal funct… --- ## [DC Electrical Fencing](https://forumautomation.com/t/dc-electrical-fencing/11290)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [July 6, 2023, 4:01am UTC](https://forumautomation.com/t/dc-electrical-fencing/11290 "2023-07-06T04:01:52Z")
Direct current electric fencing, sometimes referred to as DC electrical fencing, is a kind of fencing system utilised for protecting cattle or to secure property. It functions by shocking animals that attempt to cross th… --- ## [Advantages of an Insulator in Electrical Systems](https://forumautomation.com/t/advantages-of-an-insulator-in-electrical-systems/13743)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [November 28, 2025, 12:10pm UTC](https://forumautomation.com/t/advantages-of-an-insulator-in-electrical-systems/13743 "2025-11-28T12:10:19Z")
Insulators prevent current from flowing where it should not, protecting persons and equipment. They protect equipment by isolating live wires which prevents short circuits and electrical device damage. Insulators re… --- ## [What is 59N Protection?](https://forumautomation.com/t/what-is-59n-protection/13721)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [November 18, 2025, 7:45am UTC](https://forumautomation.com/t/what-is-59n-protection/13721 "2025-11-18T07:45:05Z")
What is 59N Protection? The 59N protection relay also called as Neutral Overvoltage (59N) Protection measures the voltage between system neutral & ground. It is intended to detect neutral displacement induced by an eart… --- ## [How important is Protection to Power Systems?](https://forumautomation.com/t/how-important-is-protection-to-power-systems/13633)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 16, 2025, 1:16pm UTC](https://forumautomation.com/t/how-important-is-protection-to-power-systems/13633 "2025-10-16T13:16:59Z")
Starting with the basics we do not live in a perfect environment and as a result, occurrences occur that endanger the smooth and ongoing operation of the electrical power facilities. To ensure the safety of human hea… --- ## [Why Protection Relays and LSIG release same LV side?](https://forumautomation.com/t/why-protection-relays-and-lsig-release-same-lv-side/13599)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [October 3, 2025, 2:11pm UTC](https://forumautomation.com/t/why-protection-relays-and-lsig-release-same-lv-side/13599 "2025-10-03T14:11:21Z")
Why Protection Relays and LSIG release same LV side? On the LV (Low Voltage) side of transformers (or) switchgear, protection relays and the ACB/MCCB’s LSIG (Long, Short, Instantaneous, Ground) release are employed to pr… --- ## [Can a battery be charged by a charged capacitor?](https://forumautomation.com/t/can-a-battery-be-charged-by-a-charged-capacitor/11464)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 9, 2023, 1:19am UTC](https://forumautomation.com/t/can-a-battery-be-charged-by-a-charged-capacitor/11464 "2023-09-09T01:19:18Z")
It is possible to charge a battery using a charged capacitor, although this usually requires more steps than simply attaching the capacitor to the battery. To ensure secure and effective charging, a circuit that regulate… --- ## [Types of Neutral Earthing](https://forumautomation.com/t/types-of-neutral-earthing/13561)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 22, 2025, 4:25pm UTC](https://forumautomation.com/t/types-of-neutral-earthing/13561 "2025-09-22T16:25:42Z")
Types of Neutral Earthing Neutral earthing (or grounding) is the process of connecting the neutral point of a generator, transformer (or) distribution system to ground. This is done to assure system safety, equipment pro… --- ## [Understanding Functional, Protective and Lightning Earthing Connections](https://forumautomation.com/t/understanding-functional-protective-and-lightning-earthing-connections/13555)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 19, 2025, 2:13pm UTC](https://forumautomation.com/t/understanding-functional-protective-and-lightning-earthing-connections/13555 "2025-09-19T14:13:55Z")
\[color=#ff0000\] Understanding Functional, Protective and Lightning Earthing Connections \[/color\] Functional earth is frequently kept separate from the protective earth. The primary objective for this separation is to red… --- ## [Overcurrent Relay: Theoretical Concepts and Design in Simulink](https://forumautomation.com/t/overcurrent-relay-theoretical-concepts-and-design-in-simulink/11931)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [April 3, 2024, 12:28pm UTC](https://forumautomation.com/t/overcurrent-relay-theoretical-concepts-and-design-in-simulink/11931 "2024-04-03T12:28:18Z")
Overcurrent relays are essential components of electrical protection systems, intended to detect and react to inappropriate currents in power systems. Understanding the theoretical concepts underlying overcurrent relays,… --- ## [What is Overvoltage Protection?](https://forumautomation.com/t/what-is-overvoltage-protection/13493)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [August 29, 2025, 12:03pm UTC](https://forumautomation.com/t/what-is-overvoltage-protection/13493 "2025-08-29T12:03:59Z")
\[color=#21855c\] What is Overvoltage? \[/color\] Overvoltage is the state in which the voltage in an electrical system exceeds its normal rated level. This unexpected voltage spike may be transitory or transient, and if no… --- ## [DIRECTIONAL COMPARISON BLOCKING SCHEME](https://forumautomation.com/t/directional-comparison-blocking-scheme/6410)
**Author:** [@Ashlin.aj](https://forumautomation.com/u/Ashlin.aj)\ **Replies:** 0\ **Last updated:** [May 18, 2019, 5:49pm UTC](https://forumautomation.com/t/directional-comparison-blocking-scheme/6410 "2019-05-18T17:49:11Z")
DIRECTIONAL COMPARISON BLOCKING SCHEME This is a high-speed protection scheme designed to provide quick tripping for faults anywhere on the protected line, this is the most common pilot relaying scheme which … --- ## [What is the purpose of an automatic voltage regulator in a DG set?](https://forumautomation.com/t/what-is-the-purpose-of-an-automatic-voltage-regulator-in-a-dg-set/12572)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [September 16, 2024, 5:29am UTC](https://forumautomation.com/t/what-is-the-purpose-of-an-automatic-voltage-regulator-in-a-dg-set/12572 "2024-09-16T05:29:22Z")
In a diesel generator (DG) set, the major responsibility of an automatic voltage regulator (AVR) is to regulate the output voltage regardless of the load variation or other operating parameters. Here are the key funct… --- ## [Distance Protection (21)](https://forumautomation.com/t/distance-protection-21/13402)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [July 29, 2025, 2:14pm UTC](https://forumautomation.com/t/distance-protection-21/13402 "2025-07-29T14:14:49Z")
Distance protection (21) (IEC Definition) A non-unit protection whose operation and selectivity depend on local measurement of electrical quantities from which the equivalent distance to the fault is evaluated by compari… --- ## [What is Ring Main Units (RMU)?](https://forumautomation.com/t/what-is-ring-main-units-rmu/11617)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [November 25, 2023, 2:54am UTC](https://forumautomation.com/t/what-is-ring-main-units-rmu/11617 "2023-11-25T02:54:34Z")
What is an RMU? An integral component of electrical distribution networks are ring main units, or RMUs. These small switchgear components regulate and safeguard the power supply in medium voltage (MV) networks. RMUs are … --- ## [UPS Topology and their Types](https://forumautomation.com/t/ups-topology-and-their-types/13146)
**Author:** [@Rabert](https://forumautomation.com/u/Rabert)\ **Replies:** 0\ **Last updated:** [April 8, 2025, 9:25am UTC](https://forumautomation.com/t/ups-topology-and-their-types/13146 "2025-04-08T09:25:33Z")
UPS Topology and their Types Not all UPS (Uninterruptible Power Supply) systems are created equal. While they all serve the same core function and providing backup power during outages and the architecture behind them … [Next page](https://forumautomation.com/tag/protection/87.md?match_all_tags=true&page=1&tags%5B%5D=protection)