18th question.

This debate seems set to rumble on and on.

BS 7288 paragraph 1 Scope: "SRCDs are only intended to provide supplementary protection downstream of the SRCD." The problem, as I have mentioned in this forum previously, is that "supplementary protection" is not defined.


So what are the differences between a BS EN 61008/61009 device and a BS 7288 one? They are different. BS 7288 paragraph 0 Introduction: "Although the BS EN 61008 and BS EN 61009 series may be applicable to “residual current devices integrated in socket-outlets” it is acknowledged that due to the specific use and location of a socket-outlet, at the boundary of the fixed installation and immediately upstream of electrical equipment powered through a plug inserted into the socket-outlet, these devices require different features."


(1) The SRCD may be operated (by ordinary persons, although it doesn't say that) several times a day.

(2) Isolation is not required because that is achieved by pulling the plug. So if you just switch off at the RCD and don't pull the plug, the load is not isolated. By contrast, the operation of a BS EN 61008/9 device does provide (at least single pole) isolation and may be locked off.

(3) "The absence of permanently connected long conductors downstream of the RCD, together with a limited number of powered appliances, justifies reduced EMC levels." So the BS 7288 SRC is not as robust as a BS EN 61008/61009 device with respect to electromagnetic disturbances.


So there we have it. The devices are different and they are not approved for the same purpose. That said, I am perfectly happy that when I use equipment outdoors, I am adequately protected by my BS 7288 SRCD.

This debate seems set to rumble on and on.

BS 7288 paragraph 1 Scope: "SRCDs are only intended to provide supplementary protection downstream of the SRCD." The problem, as I have mentioned in this forum previously, is that "supplementary protection" is not defined.


So what are the differences between a BS EN 61008/61009 device and a BS 7288 one? They are different. BS 7288 paragraph 0 Introduction: "Although the BS EN 61008 and BS EN 61009 series may be applicable to “residual current devices integrated in socket-outlets” it is acknowledged that due to the specific use and location of a socket-outlet, at the boundary of the fixed installation and immediately upstream of electrical equipment powered through a plug inserted into the socket-outlet, these devices require different features."


(1) The SRCD may be operated (by ordinary persons, although it doesn't say that) several times a day.

(2) Isolation is not required because that is achieved by pulling the plug. So if you just switch off at the RCD and don't pull the plug, the load is not isolated. By contrast, the operation of a BS EN 61008/9 device does provide (at least single pole) isolation and may be locked off.

(3) "The absence of permanently connected long conductors downstream of the RCD, together with a limited number of powered appliances, justifies reduced EMC levels." So the BS 7288 SRC is not as robust as a BS EN 61008/61009 device with respect to electromagnetic disturbances.


So there we have it. The devices are different and they are not approved for the same purpose. That said, I am perfectly happy that when I use equipment outdoors, I am adequately protected by my BS 7288 SRCD.