Re-take - Useful Information for 2394 :

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( r[SUP]1[/SUP] & R[SUP]1[/SUP] ) r[SUP]1[/SUP] , r[SUP]2[/SUP] & r[SUP]N[/SUP] are the end-to-end ring-final-circuits readings .
R[SUP]1 [/SUP]) is the maximum measured résistance of the line-conductor for a circuit .
R[SUP]2 [/SUP]) is the maximum measured résistance of the circuit-protective-conductor for a circuit .

( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) is the test reading value of the two résistance added together

 

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:rant: On rant mode , regulation 421.200

100A disconnector(s) are a higher risk of overheating they carry a heavier load . (( why not improve them )) Manufactures

Main isolation disconnectors with just one-terminal screw for a 25mm[SUP]2[/SUP] cable (( cause for concern ))
We used them in the past , 2 screw terminals used for 100A ( Switches ) disconnectors , cooker switches

Has regulation 421.200 been influenced by fire safety alone !
Are plastic consumer units being blamed for other types of electrical fires !

One aspect of an installation that is rarely upgraded ( except in extreme cases ) is the electricity supply intake equipment on the DNO side of the meter
Many of the cables , connections and cut-outs have been in place and rarely touched since they were first installed up to 60 years . plus

 

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(1) The safe isolation procedure .. ( You isolate to Stop )

(( Before starting ))
(2) remember to seek permission from a relevant responsible person , because there might be certain vital services that must not be interrupted at any time , There might be a permit to work system in place to which you will need to comply .

(3) Identify the point of isolation for the system or circuit , lock-off , place warning label , keep the key to the lock with yourself .
(4) Select the correct and mains approved test equipment , ensure that it works correctly by testing on the proving unit .
(5) Test the outgoing side of the means of isolation (( Main switch , circuit-breaker , fuse )) etc to make sure it is dead , (( Depending on the type of supply )) you will need to complete the following tests .
(6) Single-phase installations test to confirm that there is no voltage between :- Line and Neutral , Line and Earth , Neutral and Earth .
(7) Phase installations test to confirm that there is no voltage between , L1 & L2 , L1 & L3 , L1 and Neutral , L1 and Earth , L2 and L3 , L2 and Neutral , L2 and Earth , L3 and Neutral , L3 and Earth , Neutral and Earth .
(8) Re-test the test equipment on the proving unit .
(9) When isolating the main source of energy it is also essential to isolate any secondary sources such as ( standby generators , uninterruptible power supplies ( UPS ) and microgenerators )

Step 1 .
• Identify the point of isolation for the system or circuit . ( Electricity takes the path of least résistance )
• Lock off. ( Prevention )
• Place warning label (( Warning Electrician Working & Do Not Switch On ))
• Keep the key to the lock with yourself.

Step 2 .
• Select the correct and main approved test equipment .
• Ensure that it works correctly by testing on the proving unit.

Step 3 .
Objectives • Test the outgoing side of the mean of isolation ( Main switch , Circuit-breaker Fuse ) To make sure it is Dead .
• Depending on the type of the supply you will need to complete the following tests:
• Single-phase installations test to confirm that there is no voltage between :
Line & Neutral
Line & Earth
Neutral & Earth

• Three-phase installations test to confirm that there is no voltage between :
L1 & L2
L1 & L3
L1 & Neutral
L1 & Earth

L2 & L3
L2 & Neutral
L2 & Earth

L3 & Neutral
L3 & Earth
Neutral & Earth

Step 4 .
Re-test the test equipment on the proving unit

2394 your Q/As Safe isolation . When isolating the main source of energy it is also essential to isolate any (( Secondary sources )) such as :
- Standby generators . refer (9)

Re-cap “ The human body is a conductor “
Electricity must have a complete path . You only get one change to prove (( Safe Isolation )) Electricity flows through Conductors . Water , Metal . The Human body .

Circuit-breakers provided to protect Equipment not people .
Fuses , are designed for self destruction , under fault conditions .

 

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As a Skilled person, Firstly this is a template for learning curve , Excises only . What Codes , are appropriate . ?? & recommendations’
No answers will be given “ As an Inspector “

Observation

Regulation 612.10. RCD does not operate in the required time

612.1. Unable to gain access to carry out all tests. Due to the condition and/or method of installation of the electrical equipment the inspector cannot be confident that it is safe for continued use, therefore further investigation is recommended

612.1. Unable to shut-down due to client operational limitations to carry out all tests. it is the inspector’s opinion that there is no apparent risk for continued use and therefore, as agreed with the client that this observation is categorized as a limitation ( Limit ) subject to safe isolation procedures are put in place before any maintenance on electrical equipment is carried out .

612.3.2. Low insulation résistance reading(s) recorded

612.9. Unable to shut-down due to client operational limitations to carry out earth-loop-tests , readings entered are from carrying out an ( r[SUP]2 [/SUP] ) test only , with a wandering lead fed from another live source to prove earth-continuity , therefore , unable to ascertain whether the earth-loop-impedance is low enough to operate the protective device in the required time . it is the inspectors opinion that there is no apparent risk for continued use and therefore, as agreed with the client , this observation is categorized as a limitation ( Limit ) subject to safe isolation procedures are put in place before any maintenance on electrical equipment is carried out .

612.9. Unable to gain access to carry out earth-loop-tests , readings entered are from carrying out an ( r[SUP]2 [/SUP] ) test only , with a wandering lead fed from another live source to prove earth-continuity , therefore , unable to ascertain whether the earth-loop-impedance is low enough to operate the protective device in the required time . it is the inspectors opinion that there is no apparent risk for continued use and therefore, as agreed with the client , this observation is categorized as a limitation ( Limit ) subject to safe isolation procedures are put in place before any maintenance on electrical equipment is carried out .

Regulations 612. Protective device(s) removed, unable to carry out live tests
612. Testing .

Regulation 612.6. Unable to gain access to confirm whether polarity is correct , Due to the condition of the electrical equipment and/or method of installation the inspector cannot be confident that it is safe for continued use , therefore further investigation is recommended

Regulation 612.6. Unable to shut-down due to client operational limitations to confirm whether polarity is correct , it is the inspector’s opinion that there is no apparent risk for continued use and therefore , ( As Agreed with the Client ) This observation is categorized as a limitation ( Lim ) subject to safe isolation procedures are in place before any maintenance on electrical equipment is carried out .

Regulation 612.3.1. Unable to gain access to carry out insulation résistance test(s) Due to the condition of the electrical equipment and/or method of installation the inspector carrying out this inspection cannot be confident that it is safe for continued use, therefore further investigation is recommended

Regulation 612.3.1. Unable to carry out insulation résistance test(s) due to risk to (( Electronic components on the circuit )) it is the inspectors’ opinion that there is no apparent risk for continued use and therefore , as ( Agreed with the Client ) this observation is categorized as a limitation ( Lim )

Regulation 612.2.1. & 612.9. Unable to gain access to confirm whether the protective conductor is ( Continuous throughout circuit(s) Due to the conditions of the electrical equipment and/or method of installation the inspector cannot be (( Confident that it is safe for continued Use )) therefore further investigation is recommended

Regulation 612.2.1. & 612.9. Unable to shut-down due to ( Client ) operational limitations to confirm whether the protective-conductor is continuous throughout circuit(s) therefore unable to carry out an earth-loop-impedance test(s) it is the inspectors’ opinion that is no apparent risk for continued use and therefore, as (( Agreed with the Client )) this observation is categorized as a limitation ( LIM ) subject to safe isolation procedures’ are in place before any maintenance on electrical equipment is carried out .

Regulation 612.9. Unable to gain access to carry out earth-loop tests . Due to the condition of the electrical equipment and/or method of installation the inspector cannot be confident that it is safe for continued use, therefore further investigation is recommended

Regulation 612.9. Unable to shut-down due to client operational limitations to carry out earth-loop tests, it is the inspectors’ opinion that there is no apparent risk for continued use and therefore, as agreed with the client , this observation is categorized as a limitation ( LIM ) ) subject to safe isolation procedures’ are in place before any maintenance on electrical equipment is carried out .

 

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My own Option
You don't put a round peg in a square hole, however it would seem no one taught the manufacturers ? ( CCU ) 25mm[SUP]2[/SUP] Tails

 

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Periodic Inspection & Testing . You.re Q , is it fit for Continuous Use .

Re-cap , Scope : GN-3
it is essential that the inspector and the person ordering the inspection agree the extent of the installation to be inspected beforehand, and any criteria regarding the limit of the inspection. The details should be recorded on the Certificate .

Regulation 612.8.1. Unable to gain access to verify all details of the protective device. Due to the condition of the electrical equipment and/or method of installation the inspector cannot be confident that it is safe for continued use, therefore further investigation is recommended

Regulation 612.8.1. Unable to shut-down to client operational limitations to gain access to verify all details of the protective device. it is the inspectors’ opinion that there is no apparent risk for continued use and therefore, as agreed with the client, this observation is categorized as a limitation ( LIM )

 

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Regulation 612.2.2.
(( Continuity )) A test shall be made to (( Verify the continuity of each conductor )) including the protective-conductor, of every ring final circuit .

Regulation 612.2.2.
Continuity reading high on ring-final-circuit ( R[SUP]2[/SUP] ) suspect loose termination or broken ring-connection . You.re call As a Inspector

 

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Regulation 612.2.2.
(( Continuity )) A test shall be made to (( Verify the continuity of each conductor )) including the protective-conductor, of every ring final circuit .

Regulation 612.2.2.
Continuity reading high on ring-final-circuit ( R[SUP]2[/SUP] ) suspect loose termination or broken ring-connection . You.re call , As a Inspector

514.9.1. Circuit(s) description missing / no circuit chart , unable to trace circuit(s) therefore unable to carry out test(s)
514.9.1. Circuit(s) description incorrect , unable to trace circuit|(s) therefore unable to carry out test(s)
612.8.1. Details of the protective device missing or not visible , therefore unable to test for compliance ?

 

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612.1. Unable to gain access to carry out full testing due to the presence of ( Asbestos ) Due to the condition of the electrical equipment and/or method of installation the inspector cannot be confident that it is safe for continued use, therefore further investigation is recommended .

612.1. Unable to shut-down due to client operational limitations to carry all tests, it is the inspectors’ opinion that there is no apparent risk and therefore, as agreed with the client , this observation is categorized as a limitation ( LIM ) subject to safe isolation procedures are in place before any maintenance on electrical equipment is carried out .

 

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Unable to gain access to verify type and size of (( DNO fuse )) 612.1.

612.6. Polarity incorrect .
612.10. RCBO does not operate in the required time .
612.10. Time delay on RCBO operating in a time exceeding the setting of the device .
415.1.1. Where an RCBO has been installed and is used for additional-protection the RCBO failed to operate at less or equal to 40mS at a residual current of 5 IΔn

 

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612 (( Testing ))

 

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Recommendation Codes applied to Observations - 2008. Learning Curve .

• Exposed live parts that are accessible to ( Touch ) such as where live conductors have no ( or damaged ) insulation
• Incorrect polarity , or protective device in neutral conductor only .

• A 30/32A ring-final-circuit discontinuous or cross-connected with another circuit .
• Unable to trace final circuit(s)

• Insulation résistance of less than 1MΩ between live conductors connected together & Earth , when measured at the ( CCU ) with all final-circuits connected

 

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What’s in a Regulation

Regulation 132.10.
I do feel some improvement can be made on some Regulations . as so far as in the (( Wording ))

132.10. Disconnecting devices
It must be possible to isolate-circuits or equipment for:
- Inspection
- Testing
- Fault detection
- Maintenance & repair

Any devices must comply with Chapter 53 of BS-7671:

132.10. Disconnecting devices
To be provided for:
- Inspection
- Testing
- Fault detection
- Maintenance & repair

132.10 Disconnecting devices
Disconnecting (( devices )) shall be provided so as to (( permit switching )) and/or (( Isolation of the electrical installation ))
Circuit(s) or Individual items of equipment as required for operation (( so what does the regulations say ))

For what reasons
- Inspection ..
Disconnecting (( devices )) shall be provided so as to (( permit switching )) and/or (( Isolation of the electrical installation ))

- Testing
Disconnecting (( devices )) shall be provided so as to (( permit switching )) and/or (( Isolation of the electrical installation ))

- Fault detection
Disconnecting (( devices )) shall be provided so as to (( permit switching )) and/or (( Isolation of the electrical installation ))

- Maintenance & repair
Disconnecting (( devices )) shall be provided so as to (( permit switching )) and/or (( Isolation of the electrical installation ))

132.10. Disconnecting devices for isolation and/ or switching
Disconnecting devices for switching and/or isolation shall be provided in a readily accessible place so that

The Electrical installation
All Individual circuits and
All Items of equipment

are as far as possible unable to present danger as required for:
- Operation
- Inspection
- Testing
- Fault detection
- Maintenance and repair

 

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132.15. Isolation and switching
Part 4 of the IET Regulations deals with the application of protective-measures for safety and Chapter 53 with the regulations for switching devices or switchgear required for protection, isolation and switching of a consumer’s installation.

( CCU ) The consumer’s main switchgear must be readily accessible to the consumer and be able to :
- Isolate the complete installation from the supply
- Protect against overcurrent
- Cut of the current in the event of a serious fault occurring


132.15.1. Effective means ,
Suitably placed for ready operation . shall be provided so that all (( voltages may be cut off )) from every installation .
- from every-circuit therefore and / or from all-equipment .
- as may be necessary to prevent or remove danger

132.10 should not mention isolation, only disconnection or switching.

132.15.1 and .2 are meant to be covering isolation, so the removal of all voltage i.e. there is sufficient gap to prevent danger.
132.15.2 is a repeat of 132.15.1 but instead of everything they only mention fixed motors

The wording is all mixed up. in some Regulations

 

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Wiring regulation 134.1.1 states that manufactures-instructions must be followed when installing electrical equipment......

Quote : Cooker .. ( Isolation )
Electrical connections
The cooker must be supplied via a suitable (( double pole isolating switch )) having a contact separation of at least 3mm in all poles placed in a readily accessible position adjacent to the cooker.

Functional switching .. An operation intended to switch “ On or Off
Functional switching ( Control )