It's TN-C-S system. If not by using table 41.5 then how do you work this out? Reg 411.4.204 specifically mentions table 41.5Do you know the earthing system because that is in reference to a TT system.
Discuss How to determine the RCD rating in order to comply with 411.4.204 in the Electrician Courses : Electrical Quals area at ElectriciansForums.net
It's TN-C-S system. If not by using table 41.5 then how do you work this out? Reg 411.4.204 specifically mentions table 41.5Do you know the earthing system because that is in reference to a TT system.
That all of them are compliant?Yes it does but ignore that equation above it is for TT systems.
Table 41.5 has devices ranging from 30 to 500ma with maximum Zs values ranging from 1667 to 100 ohm these all far exceed your 1.69 so what does this tell you.
Well yes in terms of providing fault protection. What you need to decide is whether the circuit needs additional rcd protection on top of fault protection.That all of them are compliant?
The question isn't asking if the circuit needs RCD protection. It's asking what RCD rating is needed to comply. Can someone please just explain to me how to work out what rating is required?Well yes in terms of providing fault protection. What you need to decide is whether the circuit needs additional rcd protection on top of fault protection
An RCD has been installed in a single phase circuit due to the measured Zs exceeding the permitted value for the installed circuit breaker.Can you show the actual question.
How did you ascertain that this was a ring final circuit then? If it was then it would be supplying socket-outlets, and would require additional protection. I don't see any of that mentioned in the question.An RCD has been installed in a single phase circuit due to the measured Zs exceeding the permitted value for the installed circuit breaker.
The circuit is wired using thermoplastic 70c flat profile twin and cpc cable with 2.5mm live conductors and 1.5mm cpc to a length of 58m
The measured Ze at the origin of the circuit and TN-C-S installation is 0.33ohms. The circuit is protected by a 20A type C circuit breaker to BS EN 60898.
Determine the residual current rating of an RCD in order to comply with Regulation 411.4.204.
That was just an assumption I made. Again, the question is NOT asking whether the circuit needs additional protection. The question has already determined that the circuit requires RCD protection. I need to know how to determine what RCD rating is needed to comply with regulation 411.4.204How did you ascertain that this was a ring final circuit then? If it was then it would be supplying socket-outlets, and would require additional protection. I don't see any of that mentioned in the question.
Reply to How to determine the RCD rating in order to comply with 411.4.204 in the Electrician Courses : Electrical Quals area at ElectriciansForums.net
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