NHXMH Halogen-free sheath cable

NHXMH-J – The cable for improved response in case of fire

The installation cable with the designation NHXMH-J is a halogen free sheath cable. Most sheath cables are multi-core cables in which the cores are surrounded by a resistant PVC sheath. NHXMH-J therefore can be seen as a halogen-free alternative to the PVC installation cable NYM. The core isolation of the NHXMH consists of cross-linked polyethylene (XLPE), whereas the outer sheath is made of a halogen-free polymer compound. Since the sheath cable is halogen-free, it has improved reaction properties in case of fire. This improved reaction in case of fire is achieved by the characteristics of the cable, which only allow minimal flame propagation and smoke generation. In Germany, electrical cables with improved fire behaviour are cables which must meet the test specifications of IEC 60332-3-24 (Cat. C). The halogen-free sheath cable NHXMH is the most frequently used type of cable in this country, with improved reaction in case of fire.

Where is NHXMH-J used?

The halogen-free sheath cable is preferably used in places and buildings where there is a high concentration of people and/or material values, i.e. where enormous damage could be caused to people and material in case of fire. The previously mentioned improved fire reaction of NHXMH-J ensures low smoke generation in case of fire and prevents consequential fire damage caused by gases that contain halogen. Common examples of buildings or rooms with a high concentration of people and material assets are industrial plants, airports and hotels, underground railways, railway stations, hospitals, schools and much more.

Structure of NHXMH-J

NHXMH consists of single or multi-stranded, round copper conductors. The cores are stranded in layers and the core isolation consists of polyethylene; the outer sheath is grey and consists of one halogen free polymer compound. Core identification is done according to DIN VDE 0293-308. You can find more precise information in the NHXMH-J 3x1.5 data sheet.
Summary of the structure of NHXMH-J:
1. Round copper conductor, single or multi-stranded
2. Core isolation made of cross-linked polyethylene (XLPE)
3. Core sheathing made of halogen-free filling compound
4. Grey outer sheath made of halogen-free polymer

What are the requirements for installing NHXMH-J?

Since there are many places with high concentrations of material assets, the cable can be used in many places. But which requirements have to be considered during installation? In principle, it is possible to have a permanent installation of NHXMH-J in damp and wet rooms. NHXMH can be installed above, within and below render as well as in brickwork. Besides, the possibility of installation in concrete cannot be excluded, although the cable should not be embedded directly in shaken, vibrated or compressed concrete. What about using NHXMH-J outdoors? Outdoor installation is also possible as long as the cable is not exposed to direct sunlight i.e. must be installed in a protected manner.

NHMH-J: What's the difference to NHXMH-J?

In contrast to NHXMH, (N)HMH cables are not standardised, have no improved reaction in case of fire and their PE core isolation is not cross-linked. (N)HMH cables are also halogen-free, but they are not as easily available as NHXMH or NHXH. NHMH is therefore unsuitable for use in rooms with high concentrations of persons and material values, because the cable does not meet the requirements of DIN VDE 0100-482.

NHXMH-J: Meaning of the abbreviation

The meaning of the abbreviation is illustrated using the cable NHXMH-J 3x2.5 as an example:
N: Standard cable according to VDE
HX: Isolation made of cross-linked polyethylene (XLPE)
M: sheathed cable
H: halogen-free sheath compound
-J: with green-yellow protective conductor
3: 3 cores
x: "amount"
2.5: 2.5 mm² conductor cross-section

Conclusion on NHXMH-J as a halogen-free alternative

The halogen free cable NHXMH-J does not develop any corrosive fire gases, has no fire propagation properties and minimal smoke generation – thus significantly improving reaction in case of fire. NHXMH is an environmentally conscious alternative to flexible rubber cables or plastic cables, and can be installed in many environments: Installation in render, brickwork and embedding in concrete (except for shaken and compressed concrete) can be done without problems.
All NHXMH-J type halogen-free sheath cables are manufactured at Faber according to the highest quality standards. In our online shop, you can find NHXMH-J and NHXMH-O sheath cables with one to 24 cores, e.g. NHXMH-J 03x1.5 with three cores and NHXMH-J 05x6 with five cores. All lines and cables can be ordered from Faber by the meter.

Technical data for NHXMH-J at a glance

Here you can see the technical data for the halogen-free sheath cable NHXMH-J at a glance:
• Rated voltage: 300 / 500 V
• Test voltage: 2,000 V
• Max. operating temperature: 70 °C on conductor
• Min. operating temperature: -40 °C
• Installation temperature: max. 60 °C / min. +5 °C
• Flame retardant according to VDE 0482-266-2-4
• Conforms to the Low Voltage Directive