O.S.G. . p/19 Type of Protective Device . The Consumer Unit ( or DistributionBoard ) ( DB ) containsdevices for the Protection of the Final Circuit . AGAINST
Function (i) & (ii) are carried out usually by One Device . Circuit Breaker . Function (iii) may beCarried out by the CircuitBreaker provided for function (i) & (ii) . or by an RCD .
An RCBO . being a Combined – Circuit Breaker& RCD . Will carry out Functions .(i) – (ii) & (iii) ◄◄ :hurray:
Conforms to a Design . BritishStandards – 2008 :20:
Prospective Fault Current ( PFC ) is the ►►Highest of the ►► ( PEFC ) & ( PSCC ) ◄◄ it is the Greater of these Two. Prospective Fault Currents . :uhoh2:
Remember the Difference in wording between ( Guidance ) & ( Regulation ) :dots:
O.S.G. 10.2.2. – States . That with the Supply Connected . i) Check polarity withthe Supply Connected . Using an approved voltage indicator . ii) Earth Electrode résistanceusing a Loop Impedance tester GN-3 . p/48 . Switch OFF Supply before Disconnecting the Earth . A Loop Impedance tester is connected between the Line conductor at the Source of the TT Installation & the Earth Electrode . & a test performed . The Impedancereading taken is Treated as the Earth Electrode résistance BS-7671:2008 . Ra - I∆n ≤ 50V. iii) Earth Fault Loop Impedance . i) GN-3 . p/49 . Toverify that there is an Earth Connection .
iv) Prospective Fault Current Measurement . if not determined by Enquiry of the Distributor . Prospective Fault Current ( PFC ) is the ►►Highest of the ►► ( PEFC ) & ( PSCC ) ◄◄
GN-3 . p/52 Prospective Fault Current . Regulation 612.11. requires that the Prospective Fault Current (Ipf ) under both Short-Circuit & Earth Fault Conditions . be Measured . Calculatedor Determined by another method . At the Origin & at other relevant pointsin the Installation .
GN-3 . 434.5.1. States that the Breaking capacity rating of Each Protective Device shallbe NOT Less than the Prospective Fault Currentat its point of Installation The “ TERM “ Prospective Fault Current “ includes “the Prospective Short-Circuit Current & the Prospective Earth Fault Current . it is the Greater ofthese TwoProspective Fault Currents . Which should be Determined & Compared with the breaking capacity of the Device .
v) Functional Testing . including RCDs & Switchgear
-&-s : 2392-10 . As Testers . Sorry “ Inspectors “ On a NEW Installation you Must Not Carry Out Live Tests until you have ( Verified ◄◄) the Earth Continuity◄◄& Other Dead Tests – “ Polarity “
2392-10 . ( T ) Some times when you see it written . You get a better Picture . Yeah . Amber . :icon_bs: :uhoh2:
610.1. Every Installation shall . during its Erection& on Completion before beingput into Service . be Inspected & Tested to Verify . as far as is reasonably Practicable . that the requirementsof the Regulations have been met .
610.2. Sections . 131 .311 to 313 & 514.9.1. ( for information required for a Fundament Principles ) 610.3. The Verification shall include comparison of the “ Results “ with the relevant criteria to Confirm that therequirements of the Regulations have been Met . 610.4. For an Addition orAlteration to an Existing Installation . it shall be Verified that the Addition or Alteration complies with the Regulations .& does not Impair the Safety of the Existing Installation .
610.5 – The Verification shall be Made by A Competent Person . 610.6. On Completion ofthe Verification .According to Regulations . 610.1. to 610.5. a Certificate orCertificates . shall be Prepared .
Section 611 – Inspection : 611.1. – The Inspection shall procedure Testing & shallnormally done with that part of the InstallationUnder Inspection . ( Disconnected◄◄ ) from theSupply .
611.2. – The Inspection shall be made to Verify that theInstalled Electrical Equipment is . In Compliance withSection 511 – This may be Ascertained byMark or be Certification furnished bythe Installer or by the Manufacturer ) &
Correctly selected & erected in Accordance with theRegulations . &
Not Visibly damaged orDefective . so as to Impair Safety .
612 – Testing : ▼▼ The tests of the Regulation 612.2. to 612.13 . Where relevant . Shall be carried Out & theresults compared with the relevant criteria .
612 – Testing : ▼▼ PAGE– 157 . -&-s big time The tests of Regulation 612.2. to 612.6. . Where relevantshall be carried Out ( in that Order◄◄ ) before TheInstallation is Energised .
Where the Installation incorporates an Earth Electrode . Thetest of Regulation 612.7. shall also becarried out ( Before ◄◄) TheInstallation is Energised .
612 – Testing : ▼▼ PAGE– 157 . -&-s big time . If any Test Indicates aFailure to comply . that Test . & any preceding tests . The results of whichmay have been Influenced by the Fault has been Rectified .
Chapsplease hit the Thank you Button . I don’t know if you want any more of thisStuff . ???????????? Amber :dots:
2392-10 : We use this Dayin Day out . Yeah . “ ConsumerUnit “ :icon_bs: Section 514 : Identification& Notices .
514.8. – Identification of the Protective Device . Circuit Protective Devices are required to be Arranged & Identifiedso that the Circuit Protected may be Easily Recognised .
Workingmy why around 17[SUP]th[/SUP] Edition :hurray:
Making you Aware .
538.4. Residual Current Monitor ( RCM )
An– RCMpermanently monitors any leakage current . in the downstreamInstallation or part of it . such a device is NOT intended to provide protection against Electric Shock
538.4.1. InSupply Systems . RCMs may be installed toreduced the risk of operation of the protective device in the event of excessiveleakage current of the Installation or the connected appliances .
The RCM is intended toalert the User of the Installation before the protective device isactivated .
Wherean RCM is installed Upstream of the RCM . it is recommended that the RCM has arated residual operating current . NOT EXCEEDINGa THIRD of that of the RCD
Regulation– 132.13 . Documentation for the Electrical Installation. Requiresthat documentation . required by regulation – 514.9. & part 6 . isprovided for Every Electrical Installation .
Regulation– 134.1.1. Erection & InitialVerification of Electrical Installations . Requiresthat good workmanship shall beundertaken by Competent Persons & further requires the “ ManufacturesInstructions shall be followed . Etc .
Terequired Tests to be for “ Initial Verification“ New /Installation . Thetests should be carried out in a prescribed Sequence . Some prior to the Circuits being “ Energized “
Tests– Prior tothe installation being “ Energized “ Dead / Testing :6: 612.2.- Continuity of protective conductors . 612.2.2.- Continuity of rind final circuit conductors . 612.3.- Insulation résistance – ( IR ) 612.4.- Protection by SELV . PELV . or by electricalseparation 612.4.5.- Basic protection by a barrier or an enclosureprovided during erection . IP2X or IPXXB .or IP4X or IPXXD . 612.5.- Insulation résistance / impedance of floors & walls . 612.6.- Polarity . 612.7.- Earth electrode .
Testsfollowing the Installation being “ Energized “ :6: 612.9.- Protection by AutomaticDisconnection of the Supply- Earth Fault LoopImpedance . 612.10.- Additional protection ( RCDs ) 612.11.– Prospective faultcurrent . ( PFC ) 612.12.– Check of Phase sequence . 612.13.– Functional testing . – 2392-10 . LastTest to do . 612.14.– Verification of voltage drop . 2392-10- Verification of voltage drop is not normally required during Initial Verification . New / Installation .
526.1 – For every connectionbetween conductors . or between conductor & other equipment shall provide durableelectrical continuity & adequate mechanical strength & provide protection .
TheEarth Loop Impedance can be calculated before making the equipment live . by adding the ( R1 + R2 ) to the Earth Loop Impedance to the point of Supply . This would satisfy the First requirement of Regulation 14 –Electricity at Work Regulation 1989 .
“ Which Requires “ There must be good reason for thecircuits to be ( Live ) whilst work is carried out on them .
Working On or Near Live Conductors . Regulation 14 – Noperson shall be engaged in any work activity on or near any ( Live Conductor) other than one suitably covered with Insulating Material so as to preventDanger . That Danger may arise unless .
a)it is unreasonable in all the circumstances for it to be Dead . & b)it is reasonable in all the circumstances for him to be at work on or near itwhile it is Live . & c)suitable precautions ( including where necessary the provision of suitableprotective equipment ) are taken to prevent Injury.
Sanctionfor ( Live ) Functional Checking .
Thesatisfy regulation 14 – You have . Sound SafeSystem of Work Onlymake circuits ( Live ) wherenecessary . for the Testing . making sure which is Live & which isDead .
Workat a distance if possibly . Takenecessary precautions .
Sorry for nitpicking, but isn't copper is a better conductor than gold. Gold is better for using in contacts, as it is more resistant to oxidization. Silver has less resistance than copper.
Thanks for the posts, these are great for revision, and I couldn't resist but to comment, as I thought this myself before I lost the argument. lol
EarthFault Loop Impedance . will also need to be measured with the terminals’ disconnected .
To do this Live canbe a little bit awkward . To avoid the complication .The measurements of ( R1 + R2 ) are simply added to the Earth Loop Impedance ofthe Panel & NOTmeasured Live .
TheIlluminated Switched Probe accessory replacesthe RED 4mmtest lead . Itcan be used anywhere that the 4mm lead set is specified in this user guide . &it will add Extra Résistance to a Loop Test measurement . ◄◄
TheImpedance of the Earth Fault Current Loop starting & ending at the point ofEarth Fault . ThisImpedance is denoted by ( Zs ) TheEarth Fault Loop comprises the following . starting atthe point of Fault .
- Thecircuit protective conductor . - Theconsumer’s earthing terminal & earthing conductor - For. TN Systems . the metallic return path . - For. TT & IT Systems . the earth return path . -The path through the earthed neutral point of the transformer . - Thetransformer winding . - TheLine conductor from the transformer to the pointof fault .
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