Wiring & earthing guides
Reference articles on low-voltage installations, grouped by topic. Definitions follow IEC 60364 and BS 7671, and most guides link to the calculators that go with them.
Earthing systems
TN, TT and IT arrangements, earth electrodes, the main earthing terminal and bonding.
- Earth Electrode
- Earthed System
- Earthing Arrangements
- Electrical Earthing
- Equipotential Bonding
- Functional Earthing
- IT Earthing System
- Local Earth (Ground)
- Main Earthing Terminal
- PME (Protective Multiple Earthing) System
- TN-C Earthing System
- TN-C-S Earthing System
- TN-S Earthing System
- TT Earthing System
- Types of System Earthing for AC and DC Electrical Distribution Systems
Conductors
Line, neutral and protective conductors, and how each one is identified.
- Circuit Protective Conductor (CPC)
- Continuous Current-Carrying Capacity
- Continuous Current-Carrying Capacity of a Conductor
- Current-Carrying Conductor
- Earthed Line Conductor (LE)
- Earthing Conductor
- Electrical Conductor
- Functional Earthing Conductor (FE)
- Line Conductor (L)
- Live Conductor
- Mid-Point Conductor
- Neutral Conductor (N)
- Neutral in Electrical
- Neutral Point
- PEL Conductor
- PEM Conductor
- PEN Conductor
- Phase Conductor
- Pole Conductor (L)
- Protective Bonding Conductor (PB)
- Protective Conductor (PE)
- Protective Conductor Current
- Protective Earthing Conductor
Protection against electric shock
Basic and fault protection, touch and step voltage, and the parts and persons the standards refer to.
- Accessible Conductive Part
- Additional Protection
- Basic Insulation
- Conductive parts
- Difference Between Basic and Fault Protection
- Double or Reinforced Insulation
- Electrical Separation
- Electrically Instructed Person
- Electrically Skilled Person
- Exposed Conductive Part
- Extra-Low Voltage Provided by SELV and PELV
- Extraneous Conductive Parts
- Hazardous-Live-Part
- Live Parts
- Ordinary Person
- Protection Against Electric Shock
- Single Fault Conditions Explained
- Step Voltage
- Touch Current
- Touch Voltage
Circuit-breakers and fault currents
Trip curves, tripping times, selectivity and the fault currents a breaker has to clear.
- 1P, 1P+N, 2P, 3P and 4P Circuit Breakers
- Circuit Breaker Selectivity
- Consumer Unit
- Earth Fault
- Earth Fault Current
- How to Read Circuit Breaker Markings and Labels
- MCB Trip Curves B, C and D
- Methods for Short-Circuit Current Calculation
- Overcurrent
- Short-Circuit Current
- Shunt Trip and Undervoltage Release
- Tripping Time of a Circuit Breaker
RCDs, RCBOs and AFDDs
Residual current and arc fault protection, device types and how to read their markings.
- AFDD (Arc Fault Detection Device)
- How to Read Residual Current Device (RCD) Markings and Labels
- Leakage Current
- RCBO (Residual Current Operated Circuit Breaker)
- RCD Types (Type AC, Type A, Type F & Type B)
- Residual Current
- Residual Current Circuit Breaker (RCCB)
- Residual Current Device (RCD)
- Residual Current Unit
Overvoltage and surge protection
SPD types and installation, and the voltage disturbances they deal with.
Electrical equipment
Equipment classes, enclosures, IP codes and switchgear.
- Class 1 Electrical Equipment
- Class 2 Electrical Equipment
- Class 3 Electrical Equipment
- Degree of Protection of Enclosure (IP Code)
- Electrical Enclosure
- Electrical Equipment
- Fixed Electrical Equipment
- Hand-Held Electrical Equipment
- Permanently Connected Electrical Equipment
- Pluggable Electrical Equipment
- Portable Electrical Equipment
- Stationary Electrical Equipment
- Switchgear and Controlgear
Installations and circuits
How an installation is organised, from the origin to the final circuit, and the voltages involved.
- Electric Circuit of an Electrical Installation
- Electrical Distribution Circuit
- Electrical Distribution Network
- Electrical Distribution System
- Electrical Installation of Building
- Electrical Riser
- Final Electric Circuit (Branch Circuit)
- Low Voltage (LV)
- Main Distribution Board (MDB)
- Nominal Voltage of an Electrical Installation
- Normal Conditions
- Origin of the Electrical Installation
- Protective Measure
- Voltage
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