# IEC 60079-14 — Electrical Installations Design, Selection and Erection

> IEC 60079-14 is the installation manual for hazardous areas. It specifies cable selection, segregation, gland choice, equipotential bonding, IS loop documentation, marking, and verification activities for the design and erection of Ex installations.

- Source : https://industryhub.site/en/standards/iec-60079-14
- Body : IEC
- Family : Hazardous Areas
- Status : current
- First published : 1996
- Latest revision : 2013 (Edition 5) + amendments
- Edition : 5
- Next revision : Edition 6 in active development
- Access : Paid (IEC webstore — ~280 CHF)
- Language : English

## Document structure

- **IEC 60079-14:2013** — Electrical installations design, selection and erection : Comprehensive : ~20 clauses covering cable selection, cable entry methods, IS system documentation, equipotential bonding, Ex e motor protection, transformer requirements, lighting, and the EX EQUIPMENT REGISTER requirements.

## Key concepts

- **Ex Register** : Mandatory document : list of every Ex device in the installation with location, certificate reference, marking, last inspection date. Maintained continuously. First thing audited by competent authority.
- **Cable selection** : Cables for Ex installations have additional requirements beyond IEC 60364 : flame retardancy (often LSOH), mechanical robustness, specific insulation for the protection method (IS cables typically blue jacketed for visual identification).
- **Cable gland selection** : Different methods : compression (most common), barrier (for indirect entry into Ex d, compound-filled), threaded conduit. Gland MUST match enclosure protection : Ex d gland on Ex d enclosure, Ex e gland on Ex e enclosure. Mismatches void certification.
- **Equipotential bonding** : All metallic structures and conductive parts in the hazardous area must be bonded together to prevent static charges and stray currents. Earth resistance < specific values per zone (typically < 1 ohm at junctions).
- **Cable segregation** : IS circuits MUST be segregated from non-IS power circuits. Different cable trays, different conduit, color-coded (blue for IS). Minimum separation distances specified.
- **Installation document** : For each IS loop, a document proving the loop is intrinsically safe : barrier+device entity parameters match, cable contribution (Cc, Lc) accounted for, calculations preserved. Required for any IS audit.

## The installation-quality multiplier

You can buy a million euros of Ex-certified equipment. If the installation is sloppy — wrong cable gland, missing stopping plug, broken equipotential bonding — the certification is **void in practice** and the area is **not safe**.

IEC 60079-14 is the installation discipline that turns certified equipment into a certified installation.

## The 5 deliverables of a compliant Ex installation

1. **Area Classification Document** (per IEC 60079-10-1/2) — already exists from upstream
2. **Equipment list with Ex marking compliance** — each device matches its zone
3. **Installation drawings** — including cable routing, segregation, bonding
4. **Ex Register** — operational document for inspection regime
5. **IS Loop documentation** — for every IS circuit, the calculation showing entity parameter compliance (Ui ≥ Uo, etc.)

These deliverables are auditable and required by ATEX 99/92/EC (workplace directive). Missing any of them = legal non-compliance.

## Cable gland selection — the most common error

The cable gland on every entry point of every Ex enclosure must be **certified for that protection method and that enclosure**. Common mistakes :

**Mistake 1** : Generic compression gland used on Ex d enclosure. Ex d requires a **barrier gland** (compound-filled) if the cable is "indirect entry" — i.e., the cable doesn't go directly outdoors and could carry hot gases internally.

**Mistake 2** : Stopping plug missing on unused entry. Every unused entry must be plugged with a **certified stopping plug** matching the enclosure protection method.

**Mistake 3** : Wrong size gland. Glands are sized to cable OD. A loose gland is not sealed properly. A too-tight gland damages the cable jacket. Both = compromised certification.

**Mistake 4** : Gland not torqued to specification. Compression glands need specific torque values to seal correctly. Eyeballing is not sufficient.

## IS loop documentation in practice

Every IS loop has a documentation file with :

```
Loop : PT-101 / Pressure indication on T-101
─────────────────────────────────────────────

Field device (Zone 1)
  Manufacturer / Model : Endress+Hauser Cerabar M PMC51
  Certificate : KEMA 14 ATEX 0123 X
  Entity parameters :  Ui = 30V    Ii = 100mA   Pi = 0.75W
                       Ci = 15 nF   Li = 200 µH

Cable (in IS tray, blue jacket)
  Type / Length : H05V2-K 2×1.5 mm² / 200 m
  Capacitance contribution Cc : 200 m × 100 pF/m = 20 nF
  Inductance contribution Lc : 200 m × 1 µH/m = 200 µH

Barrier / Isolator (in safe area cabinet C-101)
  Manufacturer / Model : Pepperl+Fuchs KFD2-STC4-Ex1
  Certificate : KEMA 13 ATEX 0456 X
  Entity parameters :  Uo = 26V    Io = 80mA    Po = 0.52W
                       Co = 240 nF  Lo = 4 mH

VERIFICATION
  Ui ≥ Uo :   30V ≥ 26V  ✓
  Ii ≥ Io :   100mA ≥ 80mA  ✓
  Pi ≥ Po :   0.75W ≥ 0.52W  ✓
  Ci + Cc ≤ Co :   15+20 = 35 nF ≤ 240 nF  ✓
  Li + Lc ≤ Lo :   0.2+0.2 = 0.4 mH ≤ 4 mH  ✓

Conclusion : Loop is intrinsically safe per IEC 60079-25.

Designed by:  [name]   Date: [date]
Reviewed by:  [name]   Date: [date]
```

Every facility maintains hundreds to thousands of these IS loop documents in a controlled file system (often the MES or a dedicated Ex management software).

## Equipotential bonding — invisible but critical

In hazardous areas, **all metallic parts** (process piping, structural steel, motor frames, control panels, cable trays) must be **bonded together** through a continuous low-resistance path. Reasons :
- Prevents static charge buildup (static spark = ignition source)
- Prevents stray currents from external faults running through the Ex area
- Provides reliable earthing for fault-current protection devices

Typical requirement : **< 1 ohm resistance** between any two bonded points. Verified by ohmmeter measurements during commissioning and periodic inspections.

Missing bonding strap on a single process flange in a Zone 1 area = legal non-conformity. Easy to miss visually, easy to catch with proper inspection regime.

## Applicable industries

All industries with hazardous areas

## References & further reading

- [IEC 60079-14:2013 — official](https://webstore.iec.ch/publication/621)