The components of a SPD: Difference between revisions
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The SPD chiefly consists of (see {{FigRef|J50}}): | |||
'''1)''' one or more nonlinear components: the live part (varistor, gas discharge tube, etc.); | |||
'''2)''' a thermal protective device (internal disconnector) which protects it from thermal runaway at end of life (SPD with varistor); | |||
'''3)''' an indicator which indicates end of life of the SPD; | |||
: Some SPDs allow remote reporting of this indication; | |||
== Technology of the live part | '''4)''' an external SCPD which provides protection against short circuits (this device can be integrated into the SPD). | ||
{{FigImage|DB422510|svg|J50|Diagram of a SPD}} | |||
== Technology of the live part == | |||
Several technologies are available to implement the live part. They each have advantages and disadvantages: | Several technologies are available to implement the live part. They each have advantages and disadvantages: | ||
*Zener diodes; | *Zener diodes; | ||
*The gas discharge tube (controlled or not controlled); | *The gas discharge tube (controlled or not controlled); | ||
| Line 18: | Line 22: | ||
The table below shows the characteristics and the arrangements of 3 commonly used technologies. | The table below shows the characteristics and the arrangements of 3 commonly used technologies. | ||
{{tb-start|id=Tab1302|num=J51|title=Summary performance table|cols=5}} | |||
{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
| Line 23: | Line 28: | ||
! Gas Discharge Tube (GDT) | ! Gas Discharge Tube (GDT) | ||
! Encapsulated spark gap | ! Encapsulated spark gap | ||
! Zinc oxide varistor | ! Zinc oxide varistor | ||
! GDT and varistor in series | ! GDT and varistor in series | ||
! Encapsulated spark gap and varistor in parallel | ! Encapsulated spark gap and varistor in parallel | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | '''Characteristics''' | ||
! | ! | ||
! | ! | ||
| Line 34: | Line 39: | ||
! | ! | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | | ||
| valign="middle" | [[File: | | valign="middle" | [[File:DB422511.png]] | ||
| valign="middle" | [[File: | | valign="middle" | [[File:DB422512.png]] | ||
| [[File: | | [[File:DB422513.png]] | ||
| [[File: | | [[File:DB422514.png]] | ||
| [[File: | | [[File:DB422515.png]] | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | '''Operating mode''' | ||
| Voltage switching | | Voltage switching | ||
| Voltage switching | | Voltage switching | ||
| Line 48: | Line 53: | ||
| Voltage-switching and -limiting in parallel | | Voltage-switching and -limiting in parallel | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | '''Operating curves''' | ||
| valign="middle" align="center" colspan="2" | [[File: | | valign="middle" align="center" colspan="2" | [[File:DB422516.png]] | ||
| valign="middle" align="center" | [[File: | | valign="middle" align="center" | [[File:DB422517.png]] | ||
| {{ | | {{tb-HC2}} | | ||
| {{ | | {{tb-HC2}} | | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | '''Application''' | ||
| | | | ||
*Telecom network | *Telecom network | ||
| Line 66: | Line 71: | ||
| LV network | | LV network | ||
|- | |- | ||
| {{ | | {{tb-HC2}} | '''SPD Type''' | ||
| Type 2 | | Type 2 | ||
| Type 1 | | Type 1 | ||
| Line 74: | Line 79: | ||
|} | |} | ||
''' | '''Note:''' Two technologies can be installed in the same SPD (see {{FigRef|J52}}) | ||
{{Gallery|J52|The Schneider Electric brand iPRD SPD incorporates a gas discharge tube between neutral and earth and varistors between phase and neutral|| | |||
{{Gallery| | |||
|PB116777.jpg|| | |PB116777.jpg|| | ||
|DB422518.svg|| | |DB422518.svg||}} | ||
}} | |||
Latest revision as of 17:50, 20 December 2019
The SPD chiefly consists of (see Fig. J50):
1) one or more nonlinear components: the live part (varistor, gas discharge tube, etc.);
2) a thermal protective device (internal disconnector) which protects it from thermal runaway at end of life (SPD with varistor);
3) an indicator which indicates end of life of the SPD;
- Some SPDs allow remote reporting of this indication;
4) an external SCPD which provides protection against short circuits (this device can be integrated into the SPD).
Fig. J50 – Diagram of a SPD
Technology of the live part
Several technologies are available to implement the live part. They each have advantages and disadvantages:
- Zener diodes;
- The gas discharge tube (controlled or not controlled);
- The varistor (zinc oxide varistor).
The table below shows the characteristics and the arrangements of 3 commonly used technologies.
Fig. J51 – Summary performance table
| Component | Gas Discharge Tube (GDT) | Encapsulated spark gap | Zinc oxide varistor | GDT and varistor in series | Encapsulated spark gap and varistor in parallel |
|---|---|---|---|---|---|
| Characteristics | |||||
|
|
|
|
| |
| Operating mode | Voltage switching | Voltage switching | Voltage limiting | Voltage-switching and -limiting in series | Voltage-switching and -limiting in parallel |
| Operating curves | 
|
|
|||
| Application |
(associated with varistor) |
LV network | LV network | LV network | LV network |
| SPD Type | Type 2 | Type 1 | Type 1 or Type 2 | Type 1+ Type 2 | Type 1+ Type 2 |
Note: Two technologies can be installed in the same SPD (see Fig. J52)
Fig. J52 – The Schneider Electric brand iPRD SPD incorporates a gas discharge tube between neutral and earth and varistors between phase and neutral
