What Is a Plastic Spiral Conduit with Pull Wire? Types and Selection
A plastic spiral conduit with pull wire is a corrugated, flexible plastic cable conduit with a draw wire placed inside during manufacture to pull cable in later.
A plastic spiral conduit with pull wire is a corrugated, flexible plastic cable protection conduit with a cable pulling wire (draw wire) placed inside during manufacture. The conduit is laid along the route first; the cable is drawn in later by pulling the wire it is tied to, so no separate fish tape is needed. The wire is only a pulling guide and adds no mechanical protection, which is why it differs from spiral conduits whose bodies are reinforced with steel wire braiding.
Which conduit for which job?
| Situation | Suitable conduit |
|---|---|
| Conduit laid first, cable pulled later; dry indoor area, light mechanical stress | Plastic spiral conduit with pull wire |
| Same job, but the route is exposed to impact and crushing | Galvanized spiral conduit with pull wire |
| Panel and machine wiring where temperature resistance is needed | Polyamide spiral conduit |
| Bundling an already installed cable harness | Helical spiral wrap |
Selection criteria
- Size: The millimetre value in the product name (14–40 mm) is the nominal size of the conduit. The inner diameter must be comfortably larger than the cable bundle; on a route with many bends the pulling force rises, so consider the next size up. Confirm the inner and outer diameters on the product page.
- Coil: The 14, 16, 18 and 20 mm conduits come in 100 m coils, the 26 and 32 mm conduits in 50 m coils and the 40 mm conduit in 25 m coils; they are sold by the metre in multiples of the coil. Cover the route with one piece; a joint breaks the continuity of the pull wire.
- Flame behaviour: The product data classifies the conduit as "flame propagating". If the specification or fire safety documents call for a non-flame-propagating conduit, these conduits are not used.
- Impact resistance: The product data gives impact resistance as "light (1 kg, 100 mm)". On routes at risk of being stepped on, crushed or struck, choose a metal conduit.
- Connection: The corrugated body cannot be threaded; it is connected to junction boxes and panel entries with a push-in fitting matching the conduit size.
How to pull the cable
- When the conduit is cut to length, the pull wire is cut too. Check that the wire sticks out at both ends and bend the ends so they cannot slip into the conduit.
- Tie the cable end firmly to the wire and wrap the joint with tape to form a smooth end that will not catch inside the conduit.
- One person feeds the cable while the other pulls the wire at a steady pace; if it gets stuck, check the bends. If more cables will be added later, pull a new draw wire through together with the cable.
Common mistakes
- Treating the pull wire as an earth or support wire: The wire is only for pulling cable; the protective (PE) conductor runs separately inside the cable.
- Overfilling the conduit: Squeezed cable has its insulation damaged when pulled and cannot dissipate heat.
- Using plastic conduit with pull wire instead of metal conduit: The plastic body is in the light impact class and does not protect the cable where there is a risk of crushing.
Related standard
The IEC 61386 (TS EN 61386) series classifies conduit systems for cable management by properties such as impact resistance, bending behaviour and flame propagation. The terms "light impact", "flexible" and "flame propagating" in the product data are classes of this kind; the product names carry no declaration of conformity with the standard, so ask the manufacturer for the certificate if needed.
Plastic spiral conduits with pull wire in the Welibaba catalogue
All 7 active products in the Wired Spiral Conduits category are Mutlusan black plastic spirals with pull wire: 14, 16, 18, 20, 26, 32 and 40 mm. Price and lead time are given on quotation.
Frequently asked questions
Can the wire in the conduit be used for earthing?
No. The wire is only for pulling cable; earthing is done with the separate protective (PE) conductor in the cable.
What is the difference between plastic conduit with pull wire and galvanized conduit with pull wire?
Both have a pulling wire; the difference is the body. The plastic conduit is light and inexpensive and is in the light impact class. The galvanized steel conduit resists crushing and impact better.
In what lengths is it sold?
Mutlusan conduits with pull wire are sold by the metre in multiples of 100, 50 or 25 m coils depending on size; the coil length is given in the product name.
Which size should I choose?
The inner diameter of the conduit must be comfortably larger than the outer diameter of the cable bundle. If the route is long or has many bends, or more cables may be added later, choose the next size up.