What is the maximum number of wires that may be used in 1 installation tube?
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Wires in installation tube
When preparing to install electrical systems, it is wise to think about installation wires (YMvK) and the right installation tubes. The yellow installation tubes for indoors are also called electrical tubes. The grey installation tubes are called impact-resistant Hostalit tubes. The Hostalit tubes are mainly used for cables and outdoors. The installation tubes must be properly matched to the selected wires. A number of regulations and rules apply to the use of installation tubes.
Please note: Installation tubes must not become loose. Mount them to the surface with clamps. Vertical clamps must be attached every 40 cm. The distance between horizontal clamps is 30 cm. The distance between the clamps from the surface-mounted equipment and accessories is 10 cm.
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What sizes of installation tube are there?
Smooth installation tube sizes:
- 16 mm (inch: 5/8")
- 19 mm (inch: 3/4")
- 25 mm (inch: 63/64")
- 32 mm (inch: 1 17/64")
- 38 mm (inch: 1 1/2")
- 50 mm (inch: 1 31/32")
Flexible installation tube sizes:
- 16 mm (inch: 5/8")
- 19 mm (inch: 3/4")
- 25 mm (inch: 63/64")
- 32 mm (inch: 1 17/64")
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Number of wires per installation tube
Depending on the diameter, you may pull a maximum number of wires through an installation tube. The NEN 3174 and NEN 3530 describe the rules that apply to this. Fewer wires may be pulled through a flexible installation tube than in comparison to a smooth, non-flexible installation tube.
Tip: Use a tension spring when pulling VD wires.
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Smooth installation tube
The most commonly used smooth installation pipes have a diameter of 16 mm (inch: 5/8″) or 19 mm (inch: 3/4″).
It is possible and permitted to combine different VD threads per pipe.
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Number of VD wires per smooth tube:
Possible combinations with VD wires:
Flexible installation tube
The most commonly used flexible installation tubes have a diameter of 16 mm (inch: 5/8″) or 19 mm (inch: 3/4″). It is possible to combine different VD threads per tube.
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Number of VD threads per flexible tube:
Number of groups through 1 installation tube
You may use one group per installation tube.
If you need 2 groups, you will need a separate installation tube for each group.
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The same rule applies to junction boxes or flush-mounted boxes as to installation tubes.
A maximum of one group may be used per junction box or flush-mounted box.
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An exception is made for a stove group.
A stove group can consist of two linked 1-phase groups, which you can see as one group.
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