Coordinated Facility Protection Catalog - Erico
Coordinated Facility Protection Catalog - Erico
Coordinated Facility Protection Catalog - Erico
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A Guide to Common Power Distribution Systems<br />
Conventional<br />
MOV<br />
With thermal<br />
disconnect<br />
Distribution Network Confi guration<br />
Between<br />
Phase (line) and<br />
Neutral Conductor<br />
Each Phase (line)<br />
Conductor and PE<br />
Neutral Conductor<br />
and PE<br />
Each Phase (line)<br />
Conductor and PEN<br />
www.erico.com 11<br />
X<br />
X<br />
X<br />
1.45 Uo<br />
SPD Uc Selection:<br />
Uo = Voltage between phase (line) and neutral conductor<br />
X = Not applied<br />
TN-C TN-S<br />
TN-C-S<br />
1.45 Uo<br />
1.45 Uo<br />
Uo<br />
X<br />
TT IT IT<br />
1.45 Uo<br />
√3 Uo<br />
Uo<br />
X<br />
with<br />
neutral<br />
conductor<br />
1.45 Uo<br />
√3 Uo<br />
Uo<br />
X<br />
without<br />
neutral<br />
conductor<br />
X<br />
√3 Uo<br />
SPD selection must consider the level of over-voltage that may occur within the distribution system<br />
due to ground faults. The above IEC ® table shows over-voltages that may occur during fault conditions<br />
for the various systems. An SPD with a Uc equal or greater than this value should be selected.<br />
With overcurrent<br />
fusing<br />
With Transient<br />
Disciminating<br />
Technology<br />
IT System<br />
A system having no direct connection between live parts and earth but all exposed-conductive-parts of the installation being connected to independent<br />
earthed electrodes.<br />
Metal Oxide Varistors (MOVs) Gas Discharge Tubes (GDTs)<br />
Two terminal<br />
gas arrester<br />
Three terminal<br />
gas arrester<br />
With failsafe<br />
device<br />
Spark Gap<br />
Uo<br />
X<br />
Other Symbols<br />
Triggered<br />
Spark Gap<br />
Silicon<br />
<strong>Protection</strong><br />
Audible<br />
Alarm
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