Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • Replies 16 replies
  • Subscribers 39 subscribers
  • Views 338 views
  • Users 0 members are here
Options
You may also be interested in

In the UK is your Domestic dwelling correctly protected by the SPD fitted in the CU/DB

Sergio Fernandez

BS7671 regulation 534.4.5, mandates that SPDs be protected against overcurrent via an MCB or Fuse
I think there are some other regulations which also state MCB/fuse protection is a requirement like


BS7671 reg 534.4.4.1.5
BS7671 reg 533.2.1
4BS7671 reg 34.5.1
BS7671 reg 712.534.101

This in my opinion goes against claims like the following and probably needs to be made clearer to the manufacturers, I would also suggest that BS7671 and GN (Guidance Notes) make this more clear for the Designer and Installer.
proteusswitchgear.com/.../

There are other manufactures also stating "No requirement for MCB" Proteus just happened to be the first my internet search engine came up with.


As always please be polite and respectful in this purely academic debate.

Come on everybody let’s help inspire the future.

Parents

  • Whether a consumer OCPD is or is not required according to BS 7671 would depend on whether the DNO agrees the service cutout rated 100 A or less can be used for this purpose (See Regulation 434.3 for fault current protection in general).

    The key issue for the consumer if an SPD OCPD is not provided at the CU, is that if the SPD fails to short-circuit, the whole installation loses power.

    However, some SPDs have OCPD built-in, in addition to specifying a "backup" OCPD for the full 16 kA protection required. It is important for the installer to know if the SPD has an additional OCPD built in ... if not, a separate external one at the CU would at least be advisable for continuity of supply.

Reply

  • Whether a consumer OCPD is or is not required according to BS 7671 would depend on whether the DNO agrees the service cutout rated 100 A or less can be used for this purpose (See Regulation 434.3 for fault current protection in general).

    The key issue for the consumer if an SPD OCPD is not provided at the CU, is that if the SPD fails to short-circuit, the whole installation loses power.

    However, some SPDs have OCPD built-in, in addition to specifying a "backup" OCPD for the full 16 kA protection required. It is important for the installer to know if the SPD has an additional OCPD built in ... if not, a separate external one at the CU would at least be advisable for continuity of supply.

Children
No Data

Community Rules & Guidelines