Electrical Installations in Hazardous Locations

Posted on Oct 19, 2024 in Physical Education

Dusty Locations

Dusty locations are those where equipment is exposed to electrical contact with enough powder to damage insulation. These locations must meet the following conditions:

  • Electrical conduits must have a minimum IP5X protection degree (Category 1 according to UNE20.324) unless higher local requirements apply.
  • Equipment must have a minimum IP5X protection degree or be enclosed within a case providing the same level of protection, unless higher local requirements apply.

High-Temperature Locations

High-temperature locations are those where the air temperature frequently exceeds 40°C or remains permanently above 35°C. The following conditions apply:

  • Cables with plastic or elastomer insulation can be used up to 50°C, applying the reduction factor indicated in UNE204605523 for admissible current intensity. Above 50°C, special cables with higher thermal stability must be used.
  • Bare conductors on insulating supports are allowed. Supports must be made of materials with stability guaranteed at the operating temperature and capable of withstanding resulting stresses.

Very Low-Temperature Locations

Very low-temperature locations are those where temperatures can reach and remain below -20°C. The following conditions apply:

  • Insulation and protective materials must not be damaged at operating temperatures.
  • Equipment must withstand stresses resulting from environmental conditions.

Battery and Accumulator Locations

Locations housing batteries that emit gases are considered corrosive environments. The following conditions apply:

  • Electrical equipment must be protected against fumes and electrolyte gases.
  • Natural or forced ventilation must ensure rapid and complete air renewal.
  • Artificial lighting must be explosion-proof and resistant to the corrosive environment.
  • Accumulators must have sufficient permanent insulation between live parts and earth.
  • Accumulators must be arranged for easy replacement and maintenance.
  • Service aisles must be at least 0.75 meters wide.
  • If DC voltage exceeds 75V, service aisle floors must be electrically isolated.

Electrical Service Locations

These locations are intended for electrical operation and are generally accessible only to qualified personnel (e.g., test labs, control rooms). They must be kept locked when unattended. The following conditions apply:

  • Access must be at least 2 meters high and 0.7 meters wide.
  • Doors must open outwards.
  • Service aisles for instruments or devices requiring constant observation or manipulation must be at least 1.10 meters wide.
  • If unprotected live parts are present, the distance between equipment must be at least 1.30 meters.
  • Service corridors must be at least 1.90 meters high, or 2.30 meters if unprotected live parts are overhead.
  • Only necessary items are allowed in service aisles.
  • Safety lighting must be provided.

Other Special Locations

In locations with specific circumstances not covered above, equipment must be selected and installed according to UNE 20.460-3DE to ensure safety and reliability. Supplementary protection can be used if equipment characteristics don’t match the local environment.

Damp Locations

Damp locations experience temporary or permanent condensation, mold, or saline deposits. Low safety voltages are recommended. The following conditions apply:

  • Conduit systems must be sealed (IPX1).
  • Prefabricated conduits must meet IPX1.
  • Surface wiring must have corrosion resistance 3.
  • Equipment must have IPX1 protection.
  • Lighting must be IPX1 and not Class 0.
  • Portable lighting must be Class 2 (ITC-BT-43).

Wet Locations

Wet locations can have moisture, mud, water drops, or fog. The following conditions apply (in addition to those for damp locations):

  • Conduit systems must be sealed (IPX4).
  • Prefabricated conduits must meet IPX4.
  • Surface wiring must have corrosion resistance 4.
  • Control and protection devices must be IPX4 or enclosed in boxes with equivalent protection.
  • Mobile or portable equipment is prohibited except for SELV circuits or MBTs (ITC36).
  • Lighting must be IPX4 and not Class 0.

Corrosive Locations

Corrosive locations contain gases or vapors that can attack electrical materials. Requirements for wet locations apply, plus external protection of equipment and conduits against corrosion.

Dusty Locations Without Fire or Explosion Risk

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