IEC 60364 vs PUE vs IS 732: comparing electrical standards

Introduction

An electrical designer working in Russia and India or with international projects encounters three standards systems:

- PUE (Electrical Installation Code, 7th ed.) — Russia and CIS countries

• IEC 60364 — international standard, basis for European norms
• IS 732 (Indian Standard, adopted from IEC 60364) — India

  Although IS 732 is based on IEC 60364, significant differences exist in practice. GorkyCAD supports calculations per all three systems — with automatic switching.

  Comparison table

  | Parameter | PUE (Russia) | IEC 60364 | IS 732 (India) |

|---|---|---|---| | Nominal voltage | 230/400 V ±10% | 230/400 V ±10% | 230/400 V (50 Hz) | | Voltage drop limit | 5% from MDB | 3% (lighting), 5% (other) | 3% (lighting), 5% (other) | | Cable sizing basis | PUE tables 1.3.4-1.3.6 | IEC 60364-5-52 | IS 732, table 5 | | Iz 2.5 mm² Cu | 27 A (3-core, in chase) | 27 A (method C) | 27 A (method C) | | Overcurrent protection | Ch. 3.1 | IEC 60364-4-43 | IS 732 Section 4 | | RCD mandatory | Cl. 7.1.71 (bathroom, sockets) | IEC 60364-4-41 | IS 732 (≤20A sockets, wet areas) | | Earthing | TN-C-S, TN-S | TN, TT, IT | TN-S (preferred) | | Selectivity | Recommended | IEC 60364-5-53 | IS 732 Section 5 | | Lightning protection | Separate standard | IEC 62305 | IS/IEC 62305 (adopted) | | S/C current calc | GOST 28249 | IEC 60909 | IS 13234 (based on IEC 60909) |

Key calculation differences

Cable current ratings

For 2.5 mm² copper, 3-core:

• PUE (in chase, brick): 27 A
• IEC 60364 (method C): 27 A
• IS 732 (method C): 27 A

→ Minimal differences here.

Voltage drop

- PUE: single 5% limit for everything

• IEC/IS: split — 3% lighting, 5% other

  A lighting circuit at 4.5% passes PUE but fails IEC/IS (needs 3%).

  RCD protection

  - PUE: mandatory for socket circuits, bathrooms. Type A recommended since 2020.

• IS 732: mandatory for all ≤20A sockets in residential + all wet-area sockets. Type A recommended.
• IEC 60364 (Germany): RCD ≤30 mA mandatory for all socket circuits ≤32 A.

  → IS 732 is generally stricter than PUE in coverage.

  Earthing system

  - Russia: TN-C-S dominant (combined PEN at input, split at MDB). PUE permits.

• India: de-facto standard — TN-S with separate N and PE throughout. IS 732 recommends TN-S for new installs.
• IEC: recognizes all systems, TN-C-S has usage restrictions.

  → For Indian projects: PEN conductor not allowed after separation point. Always run separate N and PE.

  Terminology differences

  | Russian (PUE) | English (IEC) | हिन्दी (IS 732) |

|---|---|---| | Автоматический выключатель | Circuit Breaker (MCB) | परिपथ विच्छेदक (MCB) | | УЗО | RCD | अवशिष्ट धारा युक्ति (RCD) | | ГРЩ | Main Distribution Board (MDB) | मुख्य वितरण बोर्ड (MDB) | | Сечение | Cross-Sectional Area (CSA) | अनुप्रस्थ काट क्षेत्र (CSA) |

How GorkyCAD simplifies work

1. Country/standard selection at project creation — all norms auto-configured

2. Standard switching for existing projects (e.g., started per PUE, client requested IS 732)

3. Automatic recalculation on standard change

4. Difference highlighting (where norms diverge)

5. Trilingual BOMs (Russian/English/Hindi)

For engineers working on export or with Indian clients, this saves hours of manual recalculation and cross-checking.