Paul Hanrahan asks this question about a three-phase supply arrangement and possible nuisance tripping. His question is answered by Legrand (Theme – Distribution Equipment):
|
| Protect each with a 30mA 1-phase RCD? |
|
This Q & A is one of thousands posted in our Technical Expertise area, and answered on a daily basis by our Voltimum Experts.
Question:I have a three-phase and neutral incoming supply. It is protected by a 500mA three-phase and neutral RCD. I have three separate single-phase fuseboards in the property and I want to know that whether I should protect each fuseboard with a 30mA single-phase RCD.
Could this prevent nuisance tripping, because the neutrals will be common?
Answer: Answer: Refer to the Wiring Regulations BS 7671:2008.
You really need to refer to the Wiring Regulations, but from what you have told us - i.e. the upstream three-phase protective device being 500mA and the downstream single-phase boards having 30mA protection, it will prevent nuisance tripping of the three-phase board.
Theoretically, this arrangement looks fine - however the general wiring of the installation will also need to be considered.
To see many more Q & A in Voltimum UK's Experts Area, please click on the link: www.voltimum.co.uk/consult.php?universe=consult.index.questions
|
BookmarkThis
Back