Pulling electrical wires: plan the route and quantities

This guide covers surveying and quantity planning. Work on connected wiring, conductor selection and final verification need an assessed installation design. Do not pull existing wires to discover where they lead.

Record each route separately

Draw the start and finish on a floor plan. Mark whether the conduit is new and empty or part of an existing installation. Add visible junction boxes, bends and obstructions. Leave an unknown section marked unknown; do not open electrical boxes merely to finish the drawing.

Measure along the intended wall and ceiling route, including vertical sections. The straight-line distance between two points will rarely be the ordering length. Note any section that cannot be inspected until another trade has completed its work.

The electrician determines the cable or conductors, conduit suitability and installation method. Prysmian's cable-selection guidance considers load, installation method and length among other factors. A quantity estimate does not make that design decision.

Keep a separate line for every specification

Suppose measured sections are 4.2, 2.8 and 1.5 metres: a total of 8.5 metres. If an allowance of 0.3 metres at each end has been agreed for this route, the base quantity is 9.1 metres. A user-selected 10% purchasing contingency produces an estimate of 10.01 metres.

That percentage is an example, not an electrical standard. If three different conductors are specified, record three separate 10.01-metre lines. A single line saying “30.03 metres of wire” omits the information needed to buy it. Round to retail quantities only after the exact product is known.

The Dutch term installatiedraad refers to installation wire; trekveer is the pulling tool. Check conductor cross-section in mm², colour, conductor class, insulation and product reference. Conduit outside dimensions use mm. Pipelife's electrical systems include different conduit families; nominal dimensions alone do not establish how readily a route can be pulled.

What to have ready

For surveying, use a tape measure, pencil, floor plan and available installation records. The eventual work may need the specified wires, an appropriate pulling tool, conduit fittings, boxes, connectors and verification equipment. Their quantities depend on the design, so there is no universal shopping kit for this job.

A blockage is a reason to investigate. It can indicate a tight bend, restricted space, damage or unsuitable material. Pulling harder can damage insulation without resolving the cause. Do not improvise with lubricants unless the relevant product manufacturers allow them.

Agree who will inspect the route before walls are closed and who will verify the completed installation. Keep an updated route drawing with the property records.

Common questions

Can I use existing wiring as a draw wire?

A general guide cannot establish whether that is appropriate. Its function, condition, connected equipment and isolation arrangements need assessment first.

Can I combine shorter reels?

You can add their lengths for stock records, but a continuous run still needs sufficient suitable cable on one reel. Do not introduce joints simply to use up leftovers.

Should I buy larger conduit just in case?

A different size also changes fittings and space requirements. Ask for the specified conduit system before buying.

Discuss your cable route with CAS if you would like the pulling, connections and checks included in the work. Describe which sections are new and which remain uncertain.