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Tabulated functional capabilities of LV switchgear

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After having studied the basic functions of LV switchgear (Figure H1) and the different components of switchgear, Figure H19 summarizes the capabilities of the various components to perform the basic functions.

Switchgear item Isolation Control Electrical protection
Functional Emergency switching Emergency stop (mechanical) Switching for mechanical maintenance Overload Short-circuit Electric shock
Isolator (or disconnector)[d] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Switch[e] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Residual device (RCCB)[e] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Switch- disconnector \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Contactor \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [c]
Remote control switch \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Fuse \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [f]
Circuit breaker \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [f]
Circuit-breaker disconnector[e] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [f]
Residual and overcurrent circuit-breaker (RCBO)[e] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare [a][b] \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare \definecolor{bggrey}{RGB}{234,234,234}\pagecolor{bggrey}\definecolor{myblue}{rgb}{0.26,0.71,0.9}\color{myblue}\blacksquare
Point of installation (general principle) Origin of each circuit All points where,for operational reasons it may be necessary to stop the process In general at the incoming circuit to every distribution board At the supply point to each machine and/or on the machine concerned At the supply point to each machine Origin of each circuit Origin of each circuit Origin of circuits where the earthing system is appropriate TN-S, IT, TT

[a]  Where cut-off of all active conductors is provided
[b]  It may be necessary to maintain supply to a braking system
[c]  If it is associated with a thermal relay (the combination is commonly referred to as a “discontactor”)
[d]  In certain countries a disconnector with visible contacts is mandatory at the origin of a LV installation supplied directly from a MV/LV transformer
[e]  Certain items of switchgear are suitable for isolation duties (e.g. RCCBs according to IEC 61008) without being explicitly marked as such
[f]  Circuit breaker and fuse can ensure also protective measure in case of fault by automatic disconnection of the supply

Fig. H19Functions fulfilled by different items of switchgear