Study guide
4.4 Electrical Installation Certificates & EICR Coding
AM2 / AM2S Electrical Installation Assessment Applied Knowledge
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1 Chapter 1: Safe Isolation & Risk Assessment
1.1 Safe Isolation Procedure & GS38 Standards 1.2 Site Risk Assessment & Control Hierarchy 1.3 Single-Phase, Three-Phase & Distribution Board Isolation
2 Chapter 2: Health & Safety Legislation & Site Working
2.1 Electricity at Work Regulations 1989 2.2 HASAWA 1974, RIDDOR 2013 & PUWER 1998 2.3 Working at Height, Manual Handling & COSHH 2.4 Low Voltage Systems & Permit-to-Work Controls
3 Chapter 3: Inspection, Testing & Certification (Dead Testing)
3.1 BS 7671 Part 6 Inspection & Testing Sequence 3.2 Continuity of Protective Conductors & Ring Final Circuits 3.3 Insulation Resistance & Polarity Testing
4 Chapter 4: Inspection, Testing & Certification (Live Testing & Certification)
4.1 Earth Fault Loop Impedance (Ze & Zs) Testing 4.2 Prospective Fault Current (PFC/PSCC) & Polarity 4.3 RCD Testing & Functional Checks 4.4 Electrical Installation Certificates & EICR Coding
5 Chapter 5: Fault Diagnosis & Rectification
5.1 Systematic Fault Diagnosis & Safety Precautions 5.2 Identifying Common Electrical Fault Types 5.3 Half-Split Technique & Test Equipment 5.4 Fault Rectification & Post-Repair Verification
6 Chapter 6: BS 7671 Application & Cable Selection
6.1 Cable Sizing & Correction Factors 6.2 Voltage Drop Limits & Protection Selection 6.3 Conductor Identification & Wiring Containment Systems 6.4 CPC, Main Protective & Supplementary Bonding
7 Chapter 7: Building Regulations & Special Locations
7.1 Building Regulations Part P & Competent Person Schemes 7.2 Special Locations & Bathroom Zones 7.3 Earthing Systems (TN-S, TN-C-S/PME, TT) & Consumer Units
4.4 Electrical Installation Certificates & EICR Coding
Key Takeaways Explain This Topic AI
An Electrical Installation Certificate (EIC) is required for all new installations, additions, and complete rewires.
A Minor Electrical Installation Works Certificate (MEIWC) is used for minor additions that do not involve the provision of a new circuit.
Condition codes (C1, C2, C3, FI) are strictly used in Electrical Installation Condition Reports (EICRs) to classify the severity of identified defects.
A C1 or C2 code results in an 'Unsatisfactory' EICR outcome, whereas C3 is an advisory code for improvement.
Last updated: July 2026
Statutory and Legal Context of Electrical Certification
In the United Kingdom, electrical certification is not merely administrative paperwork; it is a vital legal record required under Regulation 11 of the Electricity at Work Regulations 1989 (EAWR) and Building Regulations Part P. Certification assigns professional responsibility to the designer, installer, and tester of an installation, confirming that work complies fully with BS 7671. Failure to provide accurate certification can invalidate building insurance, breach statutory law, and expose contractors to severe legal liability in the event of an electrical injury or fire.
Types of Initial Verification Certificates
BS 7671 prescribes two primary certificates for documenting new electrical installations, alterations, and additions:
1. Electrical Installation Certificate (EIC)
The Electrical Installation Certificate (EIC) is the comprehensive document used for major electrical projects. An EIC is legally required for:
Construction of a completely new electrical installation.
Complete rewire of an existing property or commercial unit.
Addition of a new electrical circuit (e.g., installing a new dedicated EV charging circuit, solar PV circuit, or shower circuit from the distribution board).
Replacement of a Consumer Unit or distribution board.
An EIC comprises multiple structured sections, including installation address, client details, system earthing arrangements ( T N − S , T N − C − S , T T TN-S, TN-C-S, TT TN − S , TN − C − S , TT ), maximum demand, and design specifications. Crucially, it incorporates formal signed declarations for:
Design: Signed by the electrical design engineer.
Construction: Signed by the installation electrician.
Inspection & Testing: Signed by the qualified inspector.
On smaller domestic jobs, one competent electrician may sign all three declarations. The EIC must always be accompanied by a Schedule of Inspections and a Schedule of Test Results.
2. Minor Electrical Installation Works Certificate (MEIWC)
The Minor Electrical Installation Works Certificate (MEIWC) is a single-page certificate used for minor alterations or additions to existing circuits that do NOT involve the installation of a new circuit. Examples include:
Adding a socket outlet to an existing ring or radial circuit.
Adding a light fitting or switch to an existing lighting circuit.
Replacing an accessory like-for-like where circuit characteristics change.
A MEIWC cannot be used for consumer unit changes or new circuits. It records essential circuit details, protective device ratings, and key test results ( ( R 1 + R 2 ) (R_1 + R_2) ( R 1 + R 2 ) , insulation resistance, Z s Z_s Z s , and RCD trip times) to prove the alteration hasn't degraded circuit safety.
Periodic Inspection: The Electrical Installation Condition Report (EICR)
While EICs and MEIWCs certify new construction against current standards, an Electrical Installation Condition Report (EICR) evaluates an existing installation to determine whether it remains safe for continued operational service. An EICR is an in-depth health check performed periodically (e.g., every 5 years for private rented domestic properties, 3 years for industrial sites, or 1 year for educational premises).
An inspector conducting an EICR does not expect an older installation to meet modern regulations in every cosmetic detail. Instead, the inspector evaluates whether deviations present real safety hazards.
The EICR Classification Coding System
When non-compliances, defects, or safety hazards are identified during an EICR, the inspector must assign a standardized classification code defined in BS 7671 Appendix 6:
Code C1: Danger Present
Definition: Risk of injury is immediate and present. Persons using the installation are at direct risk of electric shock, burns, or fire.
Examples: Bare live conductors accessible to touch (e.g., broken socket faceplate exposing 230V terminals); live exposed metalwork due to earth fault; severe active arcing.
Mandatory Action: The inspector must immediately notify the client verbally and in writing, take immediate action to isolate the dangerous circuit if authorized, and issue a Danger Notification notice.
Overall Result: Automatically yields an UNSATISFACTORY EICR.
Code C2: Potentially Dangerous
Definition: Not immediately dangerous at the moment of inspection, but possesses defects that will become dangerous upon a single foreseeable event or fault.
Examples: Absence of earthing to metal light fittings or metallic enclosures; Z s Z_s Z s exceeding maximum limits preventing ADS; thermal damage / scorching to consumer unit main switch; undersized CPC unable to withstand fault current.
Mandatory Action: Urgent remedial action is required to rectify the defect.
Overall Result: Automatically yields an UNSATISFACTORY EICR.
Code C3: Improvement Recommended
Definition: Non-compliance with current BS 7671 standards that does not pose immediate or potential danger, but where improvement would enhance safety.
Examples: Lack of RCD protection on a socket circuit in a commercial building installed to an earlier regulation edition (where Z s Z_s Z s and bonding comply); older wiring color codes (red/black) without safety hazard; missing circuit labels.
Mandatory Action: Remedial work is recommended but not legally mandatory for safety.
Overall Result: Does NOT cause an unsatisfactory result; an installation with C3 codes receives a SATISFACTORY EICR.
Code FI: Further Investigation Required
Definition: Observations indicate a potential hazard, but full assessment requires further investigation outside the agreed inspection scope.
Examples: Unidentified cables entering an inaccessible ceiling void carrying heavy loads; unverified supply earthing origin.
Overall Result: Automatically yields an UNSATISFACTORY EICR until investigated.