Search

Search

Derating for the 3VA1 switch disconnector

The 3VA1 SD switch disconnectors do not have a trip unit. The temperature inside the switch disconnector is however influenced by the ambient temperature and the current-dependent power loss generated inside the unit. Nonetheless, 3VA1 switch disconnectors up to 125 A do not require derating up to 70 °C.

To prevent overloading of switch disconnectors up to 125 A under difficult thermal conditions, the maximum rated continuous operational current must be limited as a function of the ambient temperature:

Limitation of the rated continuous operational current in combination with accessories

The table below shows the maximum rated continuous operational current for the plug-in version of switch disconnectors in sizes 160 A and 250 A and for switch disconnectors combined with residual current devices:

None of the other available accessories require derating of the 3VA1 switch disconnector.

71674246923.png

No derating up to the rated operational current In of the molded case circuit breaker

71656506123_Table-1.png
71656506123_Table-2.png
71674246923.png

No derating up to the rated operational current In of the molded case circuit breaker

71664736779_Table-1.png
71664736779_Table-2.png