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

  • State Not Answered
  • Locked Locked
  • Replies 8 replies
  • Subscribers 32 subscribers
  • Views 1532 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Compliance with 411.3.3 RCDs on Socket Outlets

An_Cala

I have a scenario where we have a standard circuit arrangement. 32A Ring Circuit feeding a number of socket outlets.  An RCBO of 32A/30mA is specified at the DB.  However the outlets also have 10mA RCD's at each outlet.    Whilst there may be issues around nuisance tripping. ITs been suggested that we remove the RCBO and use a standard 32A Type B MCB at the DB.

 IMO this means the circuit would not have RCD protection,  and only the outlets ( or appliance plugged into an outlet would be protected).  So the question I have is would a 32A MCB Ring circuit when serving this arrangement be compliant with the regs?

One concern I have with this is that should an outlet ever be changed for a normal 13A SSO, then the circuit again would be non compliant.   And that in the event of an earth fault (depending on the ZS) it may not achieve the necessary disconnection times for a ring circuit. 

 

Thoughts? 

Parents
  • 0

    10 mA RCDs can be used for compliance with Regulation 411.3.3 of BS 7671, provided the RCD complies with one of the standards listed in Regulation Group 531.4.1.

    What standard do the socket-outlets incorporating RCDs comply with? If it's BS 7288, then  Regulation 531.4.1 does not recognise that standard for RCDs, and therefore removing the device at the origin of the circuit means the circuit would not, technically, comply with BS 7671.

    As a further consideration, is the RCD required for other purposes (e.g. certain requirements for special locations in Part 7, or Regulations 522.6.203 / 522.6.204)? If so, it's likely that the circuit needs to be protected, not the socket-outlet.

Reply
  • 0

    10 mA RCDs can be used for compliance with Regulation 411.3.3 of BS 7671, provided the RCD complies with one of the standards listed in Regulation Group 531.4.1.

    What standard do the socket-outlets incorporating RCDs comply with? If it's BS 7288, then  Regulation 531.4.1 does not recognise that standard for RCDs, and therefore removing the device at the origin of the circuit means the circuit would not, technically, comply with BS 7671.

    As a further consideration, is the RCD required for other purposes (e.g. certain requirements for special locations in Part 7, or Regulations 522.6.203 / 522.6.204)? If so, it's likely that the circuit needs to be protected, not the socket-outlet.

Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines