TIS 11-2553 is a key foundation for low-voltage electrical systems in Thailand, defining the structure, properties, and safety of wire in line with international standards. Choosing wire suited to the job — indoors, outdoors, or buried — reduces the risk of short circuits and long-term damage.
What Is TIS 11-2553, and Which Cables Does It Cover?
TIS 11-2553 defines the properties of PVC-insulated cable for voltages up to 450/750V, used in low-voltage systems in both homes and industry.
The purpose of the update:
- Align with international standards such as IEC
- Improve usage safety
- Define structure and properties clearly
- Support a variety of uses
Cables under this standard include THW (single-core), VAF (flat), and NYY (sheathed).
Which Cable Types Does TIS 11-2553 Cover?
| Standard | Cable type | Suitable use |
|---|---|---|
| TIS 11 Vol.3-2553 | Single-core, non-sheathed cable | In conduit or buried in walls; indoor installation (e.g., THW) |
| TIS 11 Vol.4-2553 | Flat cable | Surface-mounted on walls or cleated; homes (e.g., VAF) |
| TIS 11 Vol.5-2553 | General-purpose cable | General electrical work in homes and commercial buildings |
| TIS 11 Vol.101-2559 | Sheathed cable | Outdoor work, buried, damp areas (e.g., NYY) |
TIS 11-2553 and Guidelines for Standard-Compliant Wire Use
Cable structure
TIS 11-2553 defines the cable’s structure — conductor, insulation, and sheath — so the cable suits real-world conditions. A uniform design lets cable work properly with electrical equipment, reducing compatibility problems.
Test methods
Test methods were updated — voltage withstand, heat, insulation durability — to ensure the cable is safe to use, reducing the risk of premature deterioration or short circuits.
Installation rules
Guidelines include not using non-sheathed cable in cable trays, and setting minimum cable sizes, to extend life, reduce risk, and keep the system efficient.
What Colors Does the New TIS 11-2553 Wire Standard Use?
Color-assignment principle per TIS 11-2553
- Neutral (N) → blue
- Ground (G/PE) → green with yellow stripe
- Phase (L) → a color not shared with N and G
Color patterns for 1–5 core cables per TIS 11-2553
- 1-core → no fixed color
- 2-core → blue (N), brown (L)
- 3-core → green/yellow (G), blue (N), brown (L)
- 4-core → green/yellow (G), brown, black, gray
- 5-core → green/yellow (G), blue (N), brown, black, gray
Wire color standard for 1-phase and 3-phase systems
1-phase: L = brown, N = blue, G = green with yellow stripe.
3-phase: L1 = brown, L2 = black, L3 = gray, N = blue, G = green with yellow stripe.
The new color system replaces the old one (red, yellow, blue) to align with international standards.
Choose Standard-Compliant Wire for Confidence in Every Installation with TETA INTERTRADE
Understanding TIS 11-2553 helps specialists choose wire suited to the job, reducing the risk of wrong-type installation that could lead to heat build-up, short circuits, or accidents.
TETA INTERTRADE wholesales high- and low-voltage wire and electrical equipment — wire, insulators, safety gear, grounding, and lightning protection — selecting standards-compliant products at fair prices.
Contact:
- LINE: https://lin.ee/NaG9WJP
- Phone: 02-068-9690 or 086-308-3741
Frequently Asked Questions About the TIS 11-2553 Wire Standard (FAQs)
Q: Can wire without TIS 11-2553 still be used?
A: It’s not recommended, especially for permanent installations, because it may fail safety tests such as heat resistance or insulation, increasing the risk of short circuits or fire over time.
Q: Can TIS 11-2553 wire be used outdoors?
A: Yes, but choose the right type — sheathed cable (e.g., NYY) designed for sun, moisture, and outdoor conditions. Using the wrong type shortens life and risks damage.
Q: How do you check that wire complies with TIS 11-2553?
A: Check the cable directly — it must be printed with details such as the TIS standard code, cable size, voltage, and manufacturer name. Buy from a trusted seller to be sure it’s genuinely standard-compliant.
