TRATOS® 6491B – H07Z

LSZH Conduit Wire

Energy Cables / DNO Approved Cables / LV Energy Cables DNO / Building Wires LV cables DNO
Energy Cables / Low Voltage Cables - LV / LV Energy Cables BS

Cable Made In Britain - Manufactured in the UKAs the actual manufacturer of 6491B cables, not simply a distributor, Tratos has total control of the design, quality and manufacturing process from the purchase of the raw materials through to final testing and despatch to our customers. Having control of the manufacturing process Tratos have developed this cable to have the optimum balance of properties, special fire performance, toughness to withstand pulling into conduit and trunking combined with a smooth, low coefficient of friction, surface to ease installation and prevent jamming. 

Now officially identified by the designations H07Z-U and H07Z-R, 6491B cables are also known by an old CMA Code 6491B. Cables designated “-U” have class 1 conductors, “-R” have class 2 conductors” flexible class 5 conductors designated “-K” are available on request. Tratos manufacture a complete range of cables with special fire performance for building and construction applications that are both safe and reliable when correctly selected, installed and properly used.


  • BS EN 50525-3-41 – Design
  • BS EN 60228 – Conductor
  • BS EN 50363-3 – Insulation
  • BS EN 60332-1-2 – Test on single vertical cable
  • BS EN 61034-2 – Smoke emission
  • BS EN 50525-1 – Assessment of halogens for all non-metallic materials 
  • H07Z-R 1.5 mm2 to 6 mm2

Contact us:

Tel: +44 20 3148 5178


Please don’t hesitate to contact us if you need additional information about our products.


 Brochure Tratos Energy DNOs BS7870


Suitable for power and lighting circuits and building wiring. Installed in surface mounted or embedded conduits, cable trunking or similar closed systems and for fixed protected installation in or on lighting fittings and inside appliances, switchgear and control gear. In particular for installation where fire, smoke emission and toxic fumes create a potential threat.


  • Conductors: BS EN 60228 Class 1 (H07Z-U) or Class 2 (H07Z-R) plain copper 
  • Insulation: Type EI5 polyolefin cross-linked, low smoke, zero halogen (LSZH) material to EN 50363-5
  • Insulation Colour: black, blue, brown, grey, orange, pink, red, turquoise, violet, white and green-and-yellow.


Technical Specifications

  • Low voltage power
  • Rated voltage 450/750 V
  • NOTE 1 Cables rated 450/750 V may be used at 600/1 000 V when this cable is used in fixed installations with mechanical protection, within switchgear and control gear – see BS EN 50525-1.
  • Maximum continuous conductor operating temperature 90 °C.
  • Minimum installation temperatures 5 °C.
  • Minimum operation temperature once installed – 15 °C.
  • Maximum short circuit conductor temperature 250 °C, maximum duration of the fault current 5 s.

The tension applied to a cable should not exceed the values of tensile stress per conductor given below. This is subject to a total maximum tensile force of 1000 N.

  • 50 N/mm2
     during installation;
  • 15 N/mm2 for static tensile stress.

Minimum bending radius:

  • ≤8 mm 4D
  • >8 mm ≤12 mm 5D
  • >12 mm 6D


Contact us

Please, don’t hesitate to contact us for additional information on our company or our products.

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