Hager VML908CUSPD 8 Way Surge Protection Consumer Unit - Staff Review
"The VML908CUSPD high integrity consumer unit has been developed to answer the two major changes introduced by the 18th Edition Wiring Regulations which came into force on 1st January 2019, regarding 'diversity' and 'surge protection'.
It offers two x 100amp RCDs in direct response to section 536.4.202 which states '
“ ... overload protection shall not solely be based on the use of diversity factors of the downstream circuits." Whilst this regulation does not outlaw the use of diversity it does suggest that in order to avoid a risk assessment, the RCD should be nearer the total value of the downstream circuits
Chapter 44 of the 18th Edition deals with electrical surges and advises that contractors will need to install SPDs to protect against transient overvoltages in situations where there may be serious consequences. These are listed as loss of life or serious injury, interruption to public services, interruption of commercial activity, damage to cultural heritage, or impact on sites with large numbers of people. At all other sites (apart from single dwellings in some situations) a simplified risk assessment will determine the need for SPDs. The Type 2 SPD therefore negates the need for a risk assessment whilst complying with the requirement.
|Russell - December 2018