Mounting instructions

Cable trays and lighting tracks

Technical requirements

1. Standard SFS 6000
2. ST card ST 51.13 "Cable trays, ladders and lightning tracks"
3. ST card ST 51.17 "Electric cables and fire security"
4. ST card ST 51.18.01 "Sound insulation in electric lead-through installations""
5. ST card ST 51.18.02 and ST 841.10 "Fire insulation in electric lead-through installations"
6. ST card 53.21 "Protective earthing and potential evening
7. ST card ST 841.05 "Cable tray routing"
8. ST card ST 13.51 "CAD drawing characters"

General installation instructions

Tray installation shall be carried in a way that deflection of visible cable trays or lightning track does not exceed 1/200.

In industrial premises and non-visible cable trays or lightning tracks the maximum deflection is 1/100. In practice, deflection of 1/200 means that the maximum deflection in span of 3 m is not more than 15 mm. In calculation of deflection an addition of 50% of the existing load shall be taken into account as a reserve.

Sufficient space shall be left for thermal expansion of the ends and between cable trays and lightning tracks. Coefficient of thermal expansion is 0,000012 m/ºC. Thermal expansion can be calculated with the following formula: change of temperature x 0,000012 x length. If, for instance,
there is a 100 m long cable tray and a temperature change of 40ºC, the change of length is 40 x 0,000012 x 100 = 0,048 m, i.e. 48 mm.
Cable tray joints should be adjusted to 20% of span length.

In installation of cable trays and lightning tracks loading capacity of brackets and sufficient strength of fastening and surface materials shall be taken into account.

In places where vertical trays are disposed for mechanical damage, the trays shall be protected with covers up to the height of 1,5 m.


In lead-throughs of fire walls cable trays shall be cut at the wall. At borders of fire sections the lead-throughs shall comply with the fire-resistance of the surrounding construction. Different types of fire-resistant cable lead-throughs are presented in the ST card 51.18.02.

Principles for lead-through installations of cable trays, lightning tracks and conduits are presented in the ST card 51.18.01.


Shielded cables shall be used. External factors, for instance temperature, shall be taken into account. Also effect of the maximum constant current on the temperature of the cables shall be considered. On a horizontal cable tray the wires are usually installed in neatly straighned position and unfastened. On vertical and diagonal trays the wires shall be fastened at adequate intervals by using suitable fasteners.


Apparatus placed on cable trays or lightning tracks, such as distribution boxes, shall be fastened firmly and in a manner that they are not inside the actual cable space. Installation frames shall be used when necessary.

Use of high voltage cable systems
High voltage cables can be installed on cable trays KS80 and KSF80 by using cable fasteners made for this purpose.

Product liability

In installation of cable trays following shall be noted:

1. Cable trays are intended for cable suspension only.
2. In installation of cable trays and other cable track products loading capacity and sufficient strength of fastening and surface materials shall be taken into account
3. Cable trays shall not be used as ladders or walking bridges.
4. The manufacturer is not liable for direct or indirest damages caused by incorrect use of the products.