Ground Fault Protection (GFP): Difference between revisions
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{{Menu_Protection_against_electric_shocks}} | {{Menu_Protection_against_electric_shocks}} | ||
__TOC__ | __TOC__ | ||
== Different type of ground fault protections == | == Different type of ground fault protections == | ||
(see {{FigRef|F27}}) | (see {{FigRef|F27}}) | ||
Three types of GFP are possible dependind on the measuring device installed : | Three types of GFP are possible dependind on the measuring device installed : | ||
=== Residual Sensing RS === | |||
The “insulation fault” current is calculated using the vectorial sum of currents of current transformers secondaries. The current transformer on the neutral conductor is often outside the circuit-breaker. | The “insulation fault” current is calculated using the vectorial sum of currents of current transformers secondaries. The current transformer on the neutral conductor is often outside the circuit-breaker. | ||
=== Source Ground Return SGR === | |||
The | The insulation fault current is measured in the neutral – earth link of the LV transformer. The current transformer is outside the circuit-breaker. | ||
=== Zero Sequence ZS === | |||
The | The insulation fault is directly measured at the secondary of the current transformer using the sum of currents in live conductors. This type of GFP is only used with low fault current values. | ||
{{Gallery|F27|Different types of ground fault protections|150px| | |||
''''' | |DB422238a.svg||'''RS system''' | ||
|DB422238b.svg||'''SGR system''' | |||
|DB422238c.svg||'''ZS system''' }} | |||
== Positioning GFP devices in the installation == | == Positioning GFP devices in the installation == | ||
{| | {{TableStart|Tab1155|4col}} | ||
|- | |- | ||
! Type / installation level | ! Type / installation level | ||
| Line 33: | Line 36: | ||
|- | |- | ||
| Source Ground Return (SGR) | | Source Ground Return (SGR) | ||
| | | '''Possible''' | ||
| | | | ||
| Used | | Used | ||
|- | |- | ||
| Residual Sensing (RS) (SGR) | | Residual Sensing (RS) (SGR) | ||
| | | '''Possible''' | ||
| | | '''Recommended or required''' | ||
| Often used | | Often used | ||
|- | |- | ||
| Zero Sequence (SGR) | | Zero Sequence (SGR) | ||
| | | '''Possible''' | ||
| | | '''Recommended or required''' | ||
| Rarely used | | Rarely used | ||
| | |- | ||
{{TableEnd}} | |||
[[ru:Защита от замыканий на землю]] | [[ru:Защита от замыканий на землю]] | ||
[[zh:接地故障防护 (GFP)]] | [[zh:接地故障防护 (GFP)]] | ||
Revision as of 03:27, 25 November 2016
Different type of ground fault protections
(see Fig. F27)
Three types of GFP are possible dependind on the measuring device installed :
Residual Sensing RS
The “insulation fault” current is calculated using the vectorial sum of currents of current transformers secondaries. The current transformer on the neutral conductor is often outside the circuit-breaker.
Source Ground Return SGR
The insulation fault current is measured in the neutral – earth link of the LV transformer. The current transformer is outside the circuit-breaker.
Zero Sequence ZS
The insulation fault is directly measured at the secondary of the current transformer using the sum of currents in live conductors. This type of GFP is only used with low fault current values.
Fig. F27 – Different types of ground fault protections
RS system
SGR system
ZS system
Positioning GFP devices in the installation
| Type / installation level | Main-distribution | Sub-distribution | Comments |
|---|---|---|---|
| Source Ground Return (SGR) | Possible | Used | |
| Residual Sensing (RS) (SGR) | Possible | Recommended or required | Often used |
| Zero Sequence (SGR) | Possible | Recommended or required | Rarely used |
