Voltix Blog
Electrical wiring guides & calculator tutorials
Clear, practical explanations of the calculations electricians run every day - voltage drop, conductor sizing, conduit fill and the differences between NEC, BS 7671 and AS/NZS. Each guide is written for working professionals and pairs with our free online calculators.
10 May 2026 · 8 min read
Voltage Drop: What It Is, How to Calculate It, and NEC/BS 7671 Limits
Voltage drop is one of the most common compliance checks on site. Here is exactly what it is, why it matters, and how to calculate it under both NEC and BS 7671.
Read guide12 May 2026 · 9 min read
NEC Wire Sizing Guide: How to Size Conductors to NEC 310.16
Sizing conductors correctly under the NEC means more than reading one column of a table. Here is how temperature ratings, derating and the 80% rule fit together.
Read guide15 May 2026 · 9 min read
BS 7671 Cable Sizing: A Step-by-Step Guide for UK Electricians
Ib, In, Iz - the three currents at the heart of BS 7671 cable sizing. This guide walks through each correction factor with a worked domestic example.
Read guide18 May 2026 · 7 min read
NEC Conduit Fill: What the 40% Rule Really Means and How to Calculate It
Everyone quotes the '40% rule' but few explain when it applies. Here is what NEC Chapter 9 actually requires and how to calculate fill for mixed wire sizes.
Read guide22 May 2026 · 12 min read
NEC vs BS 7671 vs AS/NZS: How the Three Electrical Standards Compare
Three standards, three philosophies. This comparison maps NEC, BS 7671 and AS/NZS against each other so you can switch between them with confidence.
Read guide7 June 2026 · 9 min read
Earth Fault Loop Impedance: What It Is and How to Check It
If Zs is too high, your protective device will not trip in time during a fault. Here is everything you need to know to check it correctly.
Read guide9 June 2026 · 8 min read
Cable Derating Factors: When and How to Apply Them
Ignoring derating factors is one of the most common cable sizing mistakes. Here is when to apply them and how to do it correctly under your wiring standard.
Read guide10 June 2026 · 7 min read
Ohm's Law for Electricians: Practical Applications on Site
Ohm's Law is not just theory — it drives your fuse selection, voltage drop checks, and fault current calculations on every job. Here is how to use it in practice.
Read guide11 June 2026 · 10 min read
AS/NZS 3000 Wiring Rules: A Practical Guide for Australian Electricians
AS/NZS 3000 is the rulebook for every domestic and commercial installation in Australia and New Zealand. Here is what every electrician needs to know.
Read guide12 June 2026 · 9 min read
NEC Residential Load Calculation: Step-by-Step Service Sizing
Getting the service size right on a residential job starts with a proper load calculation. Here is how to do it step by step under NEC Article 220.
Read guide13 June 2026 · 8 min read
RCD Requirements Under BS 7671: What You Must Protect and Why
RCD requirements under BS 7671 have expanded significantly in recent editions. Here is a clear breakdown of what you must protect and how to get it right.
Read guide14 June 2026 · 9 min read
Three-Phase Power for Electricians: Calculations Made Simple
Three-phase calculations trip up a lot of electricians. Here is a clear, practical guide to line voltage, power factor, and sizing three-phase circuits correctly.
Read guide15 June 2026 · 8 min read
Protective Conductor Sizing: BS 7671, NEC and AS/NZS Rules
An undersized earth wire will not survive a fault current — it could burn out before the protective device trips. Here is how to size it correctly under your standard.
Read guide16 June 2026 · 10 min read
Motor Circuit Protection Under NEC Article 430: A Practical Guide
Motor circuits have their own sizing rules that are different from everything else in the NEC. Here is how Article 430 works in practice.
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