That is not true and is niceic wishful thinking, in fact there is no mention of srcd's in the dpc of amendment 2
As an aside, this is the position of srcd's
So what does BS 7288 say?
The residual current device at socket-outlet level is normally intended to be installed by skilled or instructed persons. It can be operated several times per day. The isolation function is not necessary since pulling out the plug from the socket-outlet is recognized as providing effective isolation. The absence of permanently connected long conductors downstream of the RCD, together with a limited number of powered appliances, justifies reduced EMC levels. Residual current devices covered by this standard are intended for additional protection in case of direct contact only. These particular features having been considered, it was recognized that a dedicated standard for socket-outlet residual current devices (SRCDs) was necessary.
This part of the introduction to the document highlights that these devices provide additional protection for direct contact only. The device itself does not achieve sufficient isolation in it's operation as it is considered that isolation can be verified with simple removal of the plug or isolation of the fcu.
Isolation is a requirement for additional protection as suggested in 415.1 of BS 7671, yet BS 7288 considers removal of the plug as isolation. This difference in consideration allows for devices to be installed in SRCDs with a much smaller clearance gap within their devices.
Manufacturers may also claim that their device complies with BS 7671, but BS 7671 has nothing to do with the construction of equipment or devices, just their selection and installation. So it is important to identify if your SRCD or other accessory, such as an FCU actually comply with the requirements of the standards mentioned within BS 7671 in Regulation 531.3.6.
So what does BS 7288 say?
This British Standard applies to residual current-operated devices (RCD) incorporated in, or specifically intended for use with, single pole and neutral and single pole and switched neutral and double pole socket-outlets, with provision of earthing of the socket-outlet for household and similar uses (SRCD:socket-outlet residual current devices). SRCDs, according to this standard, are intended to be used in single phase systems such as phase to neutral. SRCDs are only intended to provide supplementary protection downstream of the SRCD. SRCDs are intended for use in circuits where the fault protection and additional protection are already assured upstream of the SRCD.
SRCDs are neither intended to provide an isolation function nor intended to be used in IT systems.
It is clearly mentioned here that SRCDs are only to be considered for supplementary protection to the equipment connected downstream and fault protection and additional protection, as required under Regulation 415.1, shall be provided by another device upstream
The comment of additional protection is key and as we have already mentioned, BS 7288 mentions that additional protection is required upstream.
The problem is the contact separation within the BS 7288 devices is inadequate, and thus cannot meet the requirements for safe disconnection.
For compliance with the requirements of BS 7671 and other associated standards, to allow them to be used for isolation and emergency disconnection, and automatic disconnection in the event of a fault will require an update to BS 7288 and a modification to every product.
It does not look like this is forthcoming at the moment.
Thus BS 7288 devices must have an upstream 61008/9 or 62423 to meet the requirements of BS 7671.
Therefore it is not a deviation to install a BS 7288 device for additional protection, it is an outright non-compliance with BS 7671.