MV design guide - Schneider Electric
MV design guide - Schneider Electric
MV design guide - Schneider Electric
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Presentation<br />
Metal-enclosed,<br />
factory-built equipment<br />
Minimal short-circuit current: Isc (kA rms.)<br />
(see explanation in "Short-circuit currents" chapter.)<br />
Rms value of maximal short-circuit current:<br />
Ith (kA rms. 1 s or 3 s)<br />
(see explanation in "Short-circuit currents" chapter.)<br />
Peak value of maximal short-circuit: Idyn (kA peak)<br />
(value of the initial peak in the transient period)<br />
(see explanation in "Short-circuit currents" chapter.)<br />
Frequency fr (Hz)<br />
c Two frequencies are usually used throughout the world:<br />
v 50 Hz in Europe<br />
v 60 Hz in America.<br />
Several countries use both frequencies indiscriminately.<br />
Switchgear functions<br />
Designation function Current switching<br />
and symbol operating fault<br />
Disconnecter<br />
isolates<br />
Earthing disconnecter<br />
Switch<br />
isolates<br />
switches,<br />
does not isolate<br />
✔<br />
(short-circuit closing<br />
capacity)<br />
Disconnecter switch<br />
switches<br />
isolates<br />
✔<br />
Fixed circuit breaker<br />
Withdrawable circuit breaker<br />
Fixed contactor<br />
switches ✔ ✔<br />
protects<br />
does not isolate<br />
switches<br />
protects ✔ ✔<br />
isolates if withdrawn<br />
switches<br />
does not isolate<br />
✔<br />
Withdrawable contactor<br />
switches<br />
isolates if withdrawn<br />
✔<br />
Fuse<br />
protects<br />
does not isolate<br />
✔ (once)<br />
✔ = YES<br />
<strong>Schneider</strong> <strong>Electric</strong><br />
Merlin Gerin <strong>MV</strong> <strong>design</strong> <strong>guide</strong><br />
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