House Electrical Cable Guide: NYA vs NYM vs NYY, Sizes and PUIL Colour Code
Choosing a safe house electrical cable starts with the SNI mark, the right type (NYA, NYM or NYY) and the correct conductor size.
Cable is the hardest part of an installation to replace
Once walls are plastered and ceilings are closed, electrical cable is almost impossible to replace without demolition. Choosing the right SNI-certified cable at the start of a renovation is therefore much cheaper than fixing short circuits later. Here is what homeowners, contractors and building-material shops should know.
1. SNI for cables is mandatory
Minister of Industry Regulation No. 56 of 2024 (enacted 15 October 2024, promulgated 18 October 2024, effective six months after promulgation) makes SNI for cables mandatory and replaces Regulation 84/M-IND/PER/10/2014. The mandatory standards are:
- SNI 04-6629.3-2006: PVC-insulated non-sheathed cables for fixed wiring (e.g. NYA);
- SNI 04-6629.4-2006: PVC-insulated sheathed cables for fixed wiring (e.g. NYM);
- SNI 04-6629.5-2006: flexible cables (cords);
- SNI IEC 60502-1:2009 and SNI IEC 60502-2:2009: power cables from 1 kV to 30 kV (e.g. NYY).
Certified cable must bear the SNI mark and an electronic mark. One SNI certificate covers only one brand and one SNI number, and it is valid for five years. Transitional rules give 18 months to adjust older certificates.
2. NYA vs NYM vs NYY
- NYA (Cu/PVC, 450/750 V, SNI 04-6629.3): single-core copper with one layer of PVC insulation. Manufacturer Supreme Cable lists it for earthing or internal wiring in dry locations. In houses NYA should run inside conduit.
- NYM (Cu/PVC/PVC, 300/500 V, SNI 04-6629.4): two or more cores with PVC insulation and a PVC sheath. Used for permanent indoor installation, in conduit under plaster or exposed in dry locations. This is the most common cable for sockets and lighting.
- NYY (Cu/PVC/PVC, 0.6/1 kV, SNI IEC 60502-1): sheathed power cable for indoor or outdoor installation, or laying in the ground where it will not suffer mechanical damage. Suitable for runs to a guard post, water pump or garden lights.
3. Conductor size and loading
PUIL 2011 (SNI 0225:2011) sets the minimum copper conductor size for power and lighting circuits in fixed installations at 1.5 mm². The actual size must be calculated from load current, route length (voltage drop), installation method and the protective device (MCB). PUIL current-carrying capacity tables assume a 30 °C ambient temperature for cables in air, so values must be corrected in hotter spaces such as the void between ceiling and roof. For large loads such as air conditioners, water heaters or pumps, ask the installer to size the cable and MCB specifically.
4. Cable colours under PUIL
- Green-yellow may be used only for earthing and protective conductors.
- Blue is for the neutral conductor; it must not be used for earthing, nor for other functions where the installation has a neutral.
- Use other colours for phase. Never use blue or green-yellow as a phase, as it endangers the next technician.
PUIL also recognises residual current devices (RCD) with a rated residual current not exceeding 30 mA as additional protection against electric shock, but not as the sole protective measure.
5. Checking cable quality when buying
- Read the print on the sheath: brand, type (NYA/NYM/NYY), number of cores × cross-section (e.g. 3 × 2.5 mm²), rated voltage, SNI number and SNI mark.
- Measure the solid conductor diameter. Per the IEC 60228 table, a class 1 conductor of 1.5 mm² is about 1.38 mm and 2.5 mm² about 1.78 mm.
- If possible, measure resistance. IEC 60228 maximums at 20 °C for plain solid copper are 12.1 Ω/km (1.5 mm²), 7.41 Ω/km (2.5 mm²), 4.61 Ω/km (4 mm²) and 3.08 Ω/km (6 mm²). Undersized "fake gauge" cable will exceed these limits.
- Check that the coil length matches the label and the insulation is not brittle or easily torn.
FAQ
Can NYA run in the ceiling without conduit? Not recommended. NYA has only one insulation layer, so it should be inside conduit.
Can NYM be installed outdoors? The manufacturer specifies NYM for indoor or dry locations; for outdoor runs or burial use NYY.
homeX, a one-stop building materials and furniture service platform in Indonesia, supplies SNI-marked cables from several brands, backed by a showroom, warehousing and delivery. We help prepare material lists from your wiring drawings, while installation and testing are done by a competent electrician or tukang.
Sources
- JDIH BPK — Permenperin No. 56 Tahun 2024 tentang Pemberlakuan SNI untuk Kabel secara Wajib
- PT Sucaco Tbk (Supreme Cable) — Building Wire: NYA, NYM, NYY
- SNI 0225:2011 Persyaratan Umum Instalasi Listrik 2011 (PUIL 2011), PDF
- Belcom Cables — Stranding and resistance chart to IEC 60228
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