The 3300-IEC sockets are used for changing devices equipped with standard 4 mm sockets. They increase creepage distances in case of overvoltage and become safety devices which conform to IEC if used with PJP safety leads.
In use, the socket must not be energised if no connector is connected to keep its 1000 V CAT II / 600 V CAT III / 300 V CAT IV qualification.
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