Overview
Choosing the cable for electrical wiring is one of the key stages in designing an electrical installation. The wrong choice can lead to overheating, insulation damage and fire. In Russia, three main cable types are used for fixed wiring: VVGng, VVGng-LS and NYM.
VVGng (flame-retardant)
A cable with copper conductors and insulation and a sheath made of reduced-flammability PVC compound. The "ng" marking means the cable does not propagate flame when laid in bundles (GOST 31565-2012, category A).
- Application: single-run laying in cable trunking, conduits and chases
- Limitation: for bundled laying in public buildings, VVGng-LS is required
- Temperature range: from -50°C to +50°C
VVGng-LS (Low Smoke — reduced smoke emission)
It differs from VVGng in the composition of its insulation — when burning it emits a minimum of smoke and toxic gases. This is critically important for evacuating people during a fire.
- Application: mandatory in public buildings, shopping centers, hospitals, educational institutions and places of mass occupancy (SP 256.1325800.2016)
- Recommendation: recommended for apartments and residential houses as the modern standard
NYM
A cable to the German standard (an analog of VVGng), with intermediate filling of chalk-filled rubber between the conductors. This makes it easy to strip and adds fire resistance.
- Application: indoor fixed wiring, both surface and concealed laying
- Advantages: ease of installation, round cross-section, triple insulation
- Limitation: not intended for laying underground or outdoors without UV protection
Comparison Table
| Parameter | VVGng | VVGng-LS | NYM |
|---|---|---|---|
| Flame-retardant | Yes | Yes | Yes |
| Reduced smoke emission | No | Yes | No |
| Cross-section shape | Flat | Flat | Round |
| Ease of stripping | Medium | Medium | High |
| Price | Low | Medium | High |
| Standard | GOST 31996-2012 | GOST 31996-2012 | IEC 60227 |
Choosing the Cross-Section
The cable cross-section is chosen by the permissible continuous current, taking the laying method into account (PUE, tables 1.3.4–1.3.6):
- 1.5 mm² — lighting (up to 16 A)
- 2.5 mm² — socket groups (up to 25 A)
- 4.0 mm² — electric range, water heater (up to 32 A)
- 6.0 mm² — apartment supply line (up to 40 A)
- 10 mm² — house supply line (up to 63 A)
What to Choose for an Apartment
For modern apartments, VVGng-LS is recommended as the optimal choice in terms of safety and price. NYM can be used for surface laying or when ease of installation matters. VVGng is acceptable but is gradually being superseded by the LS version.
The full range of cable products is in our catalog.