Re-take - Useful Information for 2394 :

[amberleaf]

Past to Present

Loose-connections .

a loose connection downstream of an RCD . may causeit to operate due to transient-voltages or capacitive-effects . Everyconnection must be properly constructed .
Regulation – 133-01-04 : ofdurable electrical continuity & adequate mechanical strength - 526-01-01 . correctly selected - 526-02 . enclosed - 526-03 . & accessible . where required - 526-04 .

Regulation - 133-01-04 :
Every electrical-joint & connection shall be of proper construction asregards conductance . insulation .mechanical strength & protection .

Regulation - 134.1.4. :
Every electrical-joint & connection shall be of proper construction asregards conductance . insulation . mechanicalstrength & protection .

Regulation - 526-01-01:
526-01 :Connections between conductors & between a conductor & equipment .
526-01-01 : Every connections between conductors &between a conductor & equipment shall provide durable electrical-continuity& adequate mechanical strength ( see Other mechanical stresses . Regulation- 522-08: Other Mechanical Stresses ( A-J )

526 : Electrical Connections .
526.1. : Every connections between conductors& between a conductor & equipment shall provide durableelectrical-continuity & adequate mechanical strength protection
Regulation - 522.8 : Other Mechanical Stresses ( A-J )

 

[amberleaf]

by Verification . Part-6 of BS-EN-61557 .

BS-EN-61557-6 . has requirements for the following( Tests ) to be applied to RCDs .

- Non-tripping ( 50% ) test . 15mA / 30mA
- Tripping ( 100% ) test .
- 5 IΔn ( 500% ) test . - ( 5 x ) X is your multiplier . 5 x 30mA = 150mA .

 

[amberleaf]

17[SUP]th[/SUP] Edition . requirements for Testingof RCDs . Has .
The following requirements in ( Terms ) of ( Verificationof Installed-RCDs )

612.8.1. Requires the . Effectiveness of ( ADS ) of supply . by RCD to be Verifiedusing ( Test-equipment ) meeting the requirements of ( BS-EN-61557-6 ) .

 

[amberleaf]

Tripping-Current-Test : The .

Purpose of this test is to ( Confirm ) thatthe residual-operating-current . of the protective-device is less-or-equal tothe rated residual-operating-current . This.
Is a ( Measure ) of the continued effectiveness ofthe ( Device ) to work as required by . BS-7671:2011: & in accordance withits ( Product-specification ) when installed for the ( Purpose of providing )ADS . in the event of a fault . it .
Does ( Not - demonstrate ) its Suitability in terms of providing .Additional-protection . ( The Test ) should be performed in both the
i) . Positive .
ii) . Negative - half-cycles .

 

[amberleaf]

Earth-fault-loop-impedance . ( Zs )
is a . Characteristic-vital to the . protection-measure( ADS ) Automatic-disconnection ofsupply . which is used for . fault-protection .

Requirements for . Earth-Fault-Loop-Impedance . tobe ( determined )
External )earth-fault-loop-impedance ( Ze ) is one of the . Characteristic of the supplyto an installation . that have to be ( determined ) in order to meet the requirements of -Regulation - 313.1 . BS-7671:2011:

Three-Methods of determining- ( Ze )
- Calculation .
- Enquiry .
- Measurement. 2394 : in our case . “ At the Origin “

Earth-Fault-Loop-Impedance . ( Zs ) “ Circuit-loop-impedance “
Regulation - 612.9. requires that . where .protective-measures are used which require a Knowledge of the .earth-fault-loop-impedance ( Zs ) the relevant-impedances are to be
- Measured .
- Determined by an alternative-method .

- Measurement of ( Ze ) gives the present-value .
Not the “Normal-range “ of values of ( Ze ) in order to . determine the “ Normal-range“ of values of ( Ze ) also necessary touse Information-obtained either by
- Enquiry
- Calculation

- Enquiry . - ( DOES) not
- Calculation - ( DOES ) not
( DOES ) not verifythat the . intended-means of earthing is ( Present) or that the value of ( Ze ) is withinthe . expected-normal-range .

 

[amberleaf]

Usefuljunk - Crimp-Lugs .

Maximum. Elec-rating .

10mm[SUP]2 [/SUP] - 62 amp .
16mm[SUP]2 [/SUP] - 88 amp .
25mm[SUP]2 [/SUP] - 115 amp .
35mm[SUP]2 [/SUP] - 160 amp .
50mm[SUP]2 [/SUP] - 215 amp .
70mm[SUP]2 [/SUP] - 235 amp .
90mm[SUP]2 [/SUP] - 255 amp .

 

[amberleaf]

Typical causes of Unwanted-Tripping . RCD(s)

- Loose-connections .
- Incorrect-applications . ( Correctly located interminals & tight - correct polarity )
- Wet-plaster / Condensation .
- Moisture-ingress . Appliances . sockets .
- No-discrimination between RCDs .
- Cross-neutral on Split-Loads .
- Neutral to Earth-fault .
• Householder - DIY . faults .Nails / picture-hooks . ( Cutting through a cable )
• Faults on the wiring areoften caused by . Nails or Screws driven between the ( Neutral &Earth-conductors ) “ Common “
- Heating-elements - Cooker . ( Leakage-current )
- Reversed Neutral & Earth-connections .
- Neutral-conductor touching anEarthed-mounting-box .

 

[amberleaf]

Certification & Reporting .

( r[SUP]1[/SUP] . r[SUP]n [/SUP] . r[SUP]2 [/SUP] ) youhave confirmed . Continuity . & Polarity . by “ Continuity-method “

Schedule of Test-Results .
The . Schedule reminds us .Ring-final-circuit-continuity ( Ω ). ( r[SUP]1[/SUP] . r[SUP]n [/SUP] . r[SUP]2 [/SUP] ) Little - r/s . 10 . 11 . 12 .

( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) do we need a reason .
( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) is for initiallyverifying that both the Line-conductor & Circuit-protective-conductor . arepresent at points of any Utilisation .

Testing ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) Radial-circuit . the measurement can bedetermined by testing across . Line & Circuit-protective-conductor - ( CPC)

 

[amberleaf]

Useful junk . What is Part - 1 .

This is in BS-7671:2011: p.34 . “ Definitions “ RCCB. RCBO. “

Guide to Low-voltageresidual-current-operated-circuit-breaker
BS-EN-61008-1 . RCCBs - Part-1 . general-rules
( General-rules )Residual-current-operated-circuit-breakers ( Without )Integral-Overcurrent-Protection for household & similar uses .
Not-designed to performthe functions of protection against . Overload or Short-circuit .

Guide to Low-voltage circuit-breaker-standards .
BS-EN-61009-1 . RCBOs - Part-1 . General-rules
( General-rules ) Residual-current-operated-circuit-breakers. ( With ) Integral-Overcurrent-Protection forhousehold & similar uses . designed to perform the functions of protection against . Overloador Short-circuit .

 

[amberleaf]

Simple things we take for granted
Probe-contact-résistance . when we are testing . ( Pressure-applied ) it’sall in the Contact .

Crocodile-clips . when attaching the clips for ( Nulling & Measurement )

 

[amberleaf]

p.28 . Extraneous-conductive-parts .
Conductive-Parts : ≈ .
- Liable tointroduce a potential .generally .Earth-potential .
- Not . forming-part of the Installation .

 

[amberleaf]

p.34 . Simultaneously-accessible-parts :
- Conductors or Conductive-parts .
Which can be ( Touched-simultaneously )
- by a person or . locations specifically intendedfor them . by Livestock .

 

[amberleaf]

2394: Do we need reasons :
“ Confirming“ Where the supply is provided with an Earth-Connection from the DNO .Distribution-Network-Operator .
- Intended means of Earthing is defective .
- Even non-existent .
Reason : ( Ze ) by measurement also verifies the intended means of Earthingis Present .

 

[amberleaf]

-&-s : State . Verification of Polarity . ( Accessories )
( Accessories ) bydefinitions p.23 .
A device . other than current-using-equipment . (Associated with such equipment ) or with the Wiring of an Installation .

 

[amberleaf]

Installation can be (Any ) abbr : Installation
p.27: Electrical-Installation- “ Assembly of associatedelectrical-equipment having co-ordinated characteristics to fulfil aSpecific-purpose “

 

[amberleaf]

Direct measurement of ( Zs )
Q) . What is direct measurement ? A) . Direct-measurement ofEarth-fault-loop-impedance is achieved by use of an Earth-loop-impedance-tester.
This Instrument operates from the ( Main-supply ) making ita Live-Test .

- Instrument is fitted with a standard-13A plug.for connecting to the Installation directly through a normal-socket-outlet .

 

[amberleaf]

Thisbring home how Important it is to Test.

Zs. ( Accessory ) Socket-outlet(s) perform the test on the Outlet which is furthest fromthe Origin of the circuit .
Not-known !! . Test all . Socket-outlets inthe circuit & record thehighest-value .

 

[amberleaf]

State Three -documents on which the value of prospective fault current should be recorded .- at this point . look in page 391 . 397 .

( EIC ) - p.391 . Nature of Supply Parameters. Prospective fault current ( Ipf ) . “ 1.17 - kA “
Note - (2) . by enquiry or . by Measurement .

( EICR ) p.396 . Nature of Supply Parameters .Prospective fault current ( Ipf ) .
Note - (2) . by enquiry or . by Measurement .

GN-3 : p.57 .
Recording the Prospective fault Current . ( Ipf)
Both the ( EIC ) & the ( EICR ) contains a boxheaded . Nature of Supply Parameters , which requires the ( PFC ) at the origin to be recorded
This value to be recorded is the greater of etherthe . Short-circuit current ( Between live conductor ) or the Earth-faultcurrent ( between line conductor(s)& the main-earthing-terminal )

If it isconsidered necessary to record values at other relevant points , the can berecorded on the . Schedule of Test Results
Where . the protective-devices used at the originhave the necessary rated breaking capacity . & devices with similarbreaking capacity are used throughout the installation . it can be assumed thatthe Regulations are satisfied in this respect for all distribution boards .

 

[amberleaf]

Two-methods for measuring RCDs .

BS-EN-61557-6 . fitted with a ( standard-13A plug-top) by plugging the instrument into asuitable-socket-outlet . protected by the RCD under test.
(Appliances should be disconnected prior to Testing )

BS-EN-61557-6 . Tests are made on the ( Load-side ) of the RCDbetween the Line-conductor of the protected-circuit & the associated ( CPC) Circuit-protective-conductor

RCD-test-instrument(s)require a few . milliamperes to operate . this is obtained from the Line &Neutral of the circuit under-test .

 

[amberleaf]

Verificationof Test-results . 2394 :

Scheduleof Test-results : is a ( Written-record ) of the results obtained when carrying out theTests required by . Part-6 of BS-7671:2011: