A little cable lore: what are wires, cables, conductors and stranded wires??
In order to understand well the specific characteristics of the NYM cable, you should know some basic concepts. Therefore we provide small cable knowledge ahead:
A so-called NYM cable is first of all a current-conducting cable. No more, but also no less. In electrical engineering and information technology, the term cable is generally used to describe a sheathed single conductor (wire, core) or also a composite of several single conductors (wires, cores), which is flexible. In the case of multicore cables, each conductor in the cable sheath is in turn sheathed, the specialist also calls it insulated.
3-core NYM cable with conductor colors according to VDE 0293-308:2003-01 (graphic: widar23 – wikimedia / CC BY-SA 4.0)
Depending on the number of cores in the cable, it is then called accordingly single core cable or multicore cable. The cable either serves to
- power transmission (power cable) or for the
- information transmission (data cable or signal cable).
Here also the difference between the two terms cable and wire are clear:
With cable is actually the current or data. data conductor, while one speaks of a cable if this conductor (the line) is sheathed, i.e. insulated. A conductor can be a simple wire, usually made of the metal copper (followed in use by aluminum), which is also called a solid conductor, or a so-called stranded wire. These are very fine wires, which are twisted to one.
For fixed conductors for electrical installations single-wire conductors are preferably used, while movable conductors must be made of stranded wires. The strands are subject to the VDE 0295 standard, which classifies them according to cross-section and flexibility:
- cable class 1: solid conductors for single and multi-core cables for fixed installation
- Cable class 2: multi-wire conductors for single and multi-core cables for fixed installation
- cable classes 3 and 4: not assigned
- Cable class 5: fine stranded copper/aluminum conductor for single and multi-wire flexible cables
- cable class 6: fine-wire copper/aluminum conductors for single and multi-wire highly flexible cables
What is special about NYM cable??
The NYM cable is therefore a special cable, since it has a sheathing of owns. it is therefore also called sheathed cable called. The cable sheath is made of plastic, usually polyvinyl chloride. (PVC).
And this is what the capital letters NYM stand for in the type designation of the NYM cable:
- The N stands for: standardized cable
- The Y stands for: plastic insulation
- The M stands for: sheathed cable
- The J stands for: internationally marked green-yellow protective conductor
Accordingly, a NYM cable is a cable with standardized conductor. That is, there are standards that regulate the design of the NYM cable. This includes the two NYM cable standards:
- DIN VDE 0295
- IEC 60228
The standard DIN VDE 0295 corresponds to the international standards IEC 228 and HD 383.
cable colors (conductor colors)
In the so-called stripped state, a NYM cable shows what it is made of: vdifferent colored insulated cables. The colors are not arbitrarily chosen, but speak for the purpose of the respective conductor:
|black or brown (gray)||outer conductor – phase (L)||a so-called outer conductor is current-carrying and serves to supply the consumer.|
|Blue||neutral conductor (N)||the so-called neutral conductor is connected to the neutral point (center) of the low voltage network. it carries the current from the consumer back to the power source.|
|green-yellow||protective conductor (PE)||the so-called protective conductor is used to dissipate dangerous contact voltage at the conductive metal housing against ground.|
color designation of a 3-core cable: a green-yellow plastic insulation symbolizes the protective conductor, the brown cable is the outer conductor (colloquially phase) and the blue cable is the neutral conductor. (graphic: energy experts.Org)
NYM cable types
NYM cables are with three, four or five wires and different cable cross sections in the trade. If a NYM-cable has the suffix -J, it is a NYM-J-cable, i.e. one with a green-yellow protective conductor.
NYM-cable is available with
- One core, these are then grounding cables with cross sections of idr 4, 6 and 10 mm 2 ),
- Three you can buy wires with cross-sections of 1.5 and 2.5 square millimeters (mm 2 ),
- Fourcore NYM cables are available with cross-sections between 16 and 35 mm 2
- And fivecore NYM sheathed cable with cross sections between 4 and 10 mm 2 .
- There are also special NYM cables with 7 or 12 wires with diameters from 1,5 to 2,5 mm 2 .
NYM cable you buy either individually by the meter or cheaper as a practical bundle of for example 50 meters cable length each.
|NYM-J (grounding cable)||1 x 4 mm 2||0,89 €|
|NYM-J (grounding cable)||1 x 6 mm 2||1,19 €|
|NYM-J (grounding cable)||1 x 10 mm 2||1,79 €|
|NYM-J (grounding cable)||1 x 16 mm 2||2,89 €|
|NYM-J||3 x 1,5 mm 2||0,79 €|
|NYM-J||3 x 2.5 mm 2||1,29 €|
|NYM-J||3 x 4 mm 2||2,09 €|
|NYM-J||3 x 6 mm 2||2,89 €|
|NYM-J||4 x 1,5 mm 2||1,19 €|
|NYM-O||4 x 10 mm 2||5,69 €|
|NYM-J||5 x 1.5 mm 2||1,29 €|
|NYM-J||5 x 2.5 mm 2||2,19 €|
|NYM-J||5 x 4 mm 2||3,19 €|
|NYM-J||5 x 6 mm 2||3,99 €|
|NYM-J||5 x 10 mm 2||5,99 €|
|NYM-J||5 x 16 mm 2||9,89 €|
|NYM-JZ||7 x 1,5 mm 2||2,09 €|
|NYM-OZ||7 x 1,5 mm 2||2,19 €|
|NYM-JZ||7 x 2.5 mm 2||3,39 €|
|NYM-JZ||12 x 1.5 mm 2||3,49 €|
Use and handling of NYM-cable
Thanks to the PVC sheathing, the NYM-cable is for industrial use as well as for domestic use suitable. You can use the NYM cable
- Under plaster or
- Lay on plaster.
NYM cable can even be used outdoors – provided it is protected from direct sunlight.
NYM cables are like this in many areas of electrical installation used to supply power to consumers, for example lamps or sockets. Even electrical appliances with high power consumption, such as an electric stove, can be connected to the mains with this. Has a NYM cable a large cross section it can also be used for sub-distribution within electrical installations serve.
Do you want NYM-cable in already laid cable ducts lay? then a pull-in tape, for example made of perlon, helps. this is more comfortable with a commercial cable pulling set with fiberglass rod with pressed end sleeves, pulling aid, special glue as well as cable pulling stocking.