Electrical
installation,
explained.
A complete Danish reference work on electrical installation — from Ohm's law and voltage drop to cable sizing, circuits and protection against shock and overcurrent. Read the articles. Use the calculators. Ask the assistant. Same account as technical insulation.
14
Calculators
34
Articles
∞
Questions
5-core cable cross-section (L1·L2·L3·N·PE), a simple circuit U = R·I, an analogue 230 V meter and the lightning bolt for voltage. Copper marks the live conductors.
§ 01 — What you can do here
Read, calculate, choose — or ask.
Eight tools from post to installation — for apprentices, fitters and installers.
Tools in the trade
§ 02 — About the trade
Electrician
The electrical trade covers the installation, connection, fault-finding and verification of electrical systems — from a consumer unit in a home to motor controls, EV chargers and solar PV. The trade spans power and low-voltage work, so control engineering, data cabling and building automation are part of it. The work is regulated: installations follow the DS/HD 60364 series, and work on other people's installations requires an authorisation.
Questions about the trade
What does an electrician do?
An electrician installs, connects, troubleshoots and maintains electrical systems in homes, commercial buildings, industry and on construction sites. The daily work is containment and cabling, consumer units, socket outlets and lighting — but also motor installation and motor protection, control engineering and PLCs, structured data cabling, EV chargers and solar PV. Every job carries a technical decision: which cable cross-section, which breaker characteristic, which RCD type. And every new or altered installation must be verified by inspection and testing before it is energised.
What rules apply to electrical installations in Denmark?
DS/HD 60364-serien er den samlede tekniske norm for elektriske installationer i Danmark og udgives samlet i Håndbog 183. Installationsbekendtgørelsen BEK nr. 1082 af 12. juli 2016 henviser til normen: følges den, anses sikkerhedskravet for opfyldt, og vælger man en anden løsning, skal det dokumenteres. Over bekendtgørelsen står elsikkerhedsloven. Ved siden af DS/HD 60364 gælder to andre regelsæt samtidig: Fællesregulativet med netselskabernes krav i tilslutningspunktet, og bygningsreglementet BR18. Selve retten til at udføre arbejdet er også reguleret — el-installationsarbejde på andres anlæg kræver autorisation, som gives til virksomheden og forudsætter en fagligt ansvarlig og et godkendt kvalitetsledelsessystem (KLS).
How do you select a cable cross-section?
Et kabeltværsnit skal opfylde tre krav på én gang, og det største af de tre bestemmer. Belastningsevnen er den strøm, lederen kan føre kontinuerligt uden at overskride sin tilladte driftstemperatur — 70 °C for PVC-isolering, 90 °C for PEX og EPR — og tabelværdien korrigeres for installationsmetode, ophobning og omgivelsestemperatur efter DS/HD 60364-5-52. Spændingsfaldet holdes typisk inden for de anbefalede grænser i DS/HD 60364-5-52's anneks G: 3 % for belysning og 5 % for øvrigt forbrug ved forsyning fra det offentlige net. Og kortslutningskravet siger, at lederen skal kunne tåle fejlstrømmen i den tid, beskyttelsen bruger på at koble ud — den adiabatiske kontrol med k-værdier fra DS/HD 60364-4-43, tabel 43A.
What protects against electric shock?
Protection against electric shock rests on two layers: basic protection, which prevents contact with live parts, and fault protection, which disconnects the supply automatically when a fault occurs. Automatic disconnection is described in DS/HD 60364-4-41, which sets both the disconnection times and the requirement for the fault loop impedance. The residual current device — RCD or HPFI — supplements it, and the type must match the load: DS/HD 60364-7-722 prohibits type AC for EV chargers, where type A is the minimum and type B is required when the charger does not itself block smooth DC fault currents.
How do you become an electrician?
Elektriker er en erhvervsuddannelse med et grundforløb på erhvervsskolen og et hovedforløb med skiftende oplæring og skoleophold, samlet omkring 4,5-5 år, afsluttet med svendeprøve. Der er to specialer, elektriker 1 og elektriker 2, og svendeprøven består af to delprøver. Fra 1. august 2026 gælder BEK nr. 460/2026, og kompetencemålene står nu i uddannelsesordningen. Sikkerhed fylder fra første dag — de fem sikkerhedsregler efter DS/EN 50110-1 og korrekt brug af en topolet spændingsprøver er grundstof i faget, ikke overbygning.
Based on: DS/HD 60364-serien (Håndbog 183) · DS/HD 60364-4-41 · DS/HD 60364-4-43 · DS/HD 60364-5-52 · DS/HD 60364-5-54 · DS/HD 60364-7-722 · DS/EN 50110-1 · BEK nr. 1082 af 12. juli 2016 · Fællesregulativet
§ 03 — Read now
Featured articles
Featured articles
All articles →§ 04 — Tools
Work it out.
Enter the length, current and conductor material — find the smallest cross-section that keeps the voltage drop below your limit, and the nearest standard cross-section. Then verify the current-carrying capacity and short-circuit performance against DS/HD 60364-5-52.
Open calculators→Example · Cable cross-section by voltage drop
Single-phase · 230 V
§ 05 — Trade in Action
How it looks craftsmanship.
Three classic working tasks from the profession — drawn as blueprint: transformer group, motor starter and lighting plan.
Work processes
Transformer group main connections
The electrician connects the transformer group's primary and secondary windings to the terminal box — with main switch, blue neutral conductor and green-yellow PE conductor to the earth electrode.
Motor starter — direct-on-line (DOL)
The electrician connects a 3-phase motor with contactor: the power circuit carries current from the panel through fuse to the motor winding, while the control circuit with start, stop and thermal relay controls the coil.
Lighting plan with isolux curves
The electrician places luminaires in a grid over the workshop and draws isolux curves so each work surface reaches the desired lighting. Lux levels are indicative — actual lux is calculated separately.
Your trade in numbers
The buildings you work on.
Electric heating, heat pumps and the homes that need power.
283,481
Heating installation code 7 «Electric heating»
306,719
Heating installation code 5 «Heat pump»
1,656,085
Buildings used as homes (BBR group «bolig», residential)
Across Denmark, counted in BBR.
Source: BBR + DAR (Datafordeler) — bygningsindeks; grundareal fra Matriklen, jordforurening fra Danmarks Miljøportal (DKJord), fredning/SAVE fra Slots- og Kulturstyrelsen (FBB), energimærker fra Grundfasts energimærke-korpus via Grundfast · fetched
See the numbers for your municipalityElectrical installation across the country
§ 06 — Next step
One question
in Danish.
The AI assistant can size cables, explain protection, calculate power and help with real-world cases in electrical installation. Write to it as you would to a colleague.
Safety
Come home in the same state
Strøm giver ingen advarsel. Der er ingen lyd, ingen lugt og ingen farve, der fortæller dig, at klemmen er spændingsførende — og en fejl på et halvt sekund kan stoppe dit hjerte eller brænde dit ansigt. Derfor er hele elektrikerfaget bygget op om ét princip: du tror ikke, du måler. Oveni kommer alt det andet, du laver på en dag: stiger, lofter, betonstøv og gamle huse.
Safety course
41 modules · 379 min · 5 hazards that can kill
§ — Where can you read about Electrician?
Find a school near you.
Electrician is offered at 32 places in the country. The list is informational — always check the latest and complete offering on the Education Guide's vocational education map.
Schools offering the programme
Hovedstaden
04- NEXT Uddannelse København — København
- TEC — Frederiksberg
- U/NORD — Hillerød
- Campus Bornholm — Rønne
Sjælland
07- CELF — Nykøbing Falster
- EUC Sjælland — Køge
- Roskilde Tekniske Skole — Roskilde
- ZBC (Zealand Business College) — Næstved
- ZBC — Slagelse
- EUC Sjælland — Næstved
- EUC Nordvestsjælland (NEG) — Holbæk
Syddanmark
07- HANSENBERG — Kolding
- EUC Lillebælt — Fredericia
- EUC Syd — Sønderborg
- Rybners — Esbjerg
- Syddansk Erhvervsskole (SDE) — Odense
- Syddansk Erhvervsskole (SDE) — Vejle
- Svendborg Erhvervsskole (SESG) — Svendborg
Midtjylland
10- AARHUS TECH — Aarhus
- College360 — Silkeborg
- Den Jyske Håndværkerskole — Hadsten
- Learnmark Horsens — Horsens
- Skive College — Skive
- Tradium — Randers
- Uddannelsescenter Holstebro (UCH) — Holstebro
- Viden Djurs — Grenaa
- Mercantec — Viborg
- Herningsholm Erhvervsskole — Herning
Nordjylland
04- EUC Nord — Hjørring
- EUC Nordvest — Thisted
- TECHCOLLEGE — Aalborg
- EUC Nord — Frederikshavn