Requirements applicable to special installations and locations
From Electrical Installation Guide
Figure Q20 below summarizes the main requirements prescribed in many national and international standards.
Note: Section in brackets refer to sections of IEC 60364-7
| Locations | Protection principles | IP level | Wiring and cables |
Switchgear | Socket-outlets | Installation materials |
| Domestic dwellings and other habitations |
- 300 mA if the earth electrode resistance is y 80 ohms instantaneous or short time delay (type S) - 30 mA if the earth electrode resistance is u 500 ohms
- supply is from overhead line with bare conductors, and if
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20 | Switch operating handles and similar devices on distribution panels, to be mounted between 1 metre and 1.80 metre above the floor |
Protection by 30 mA RCDs |
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| Bathrooms or shower rooms (section 701) | Supplementary equipotential bonding in zones 0, 1, 2 and 3 | |||||
| Zone 0 | SELV 12 V only | 27 | Class II limited to strict minimum | Special appliances | ||
| Zone 1 | SELV 12 V | 25 | Class II limited to strict minimum | Special appliances Water heater | ||
| Zone 2 | SELV 12 V or 30 mA RCD | 24 | Class II limited to strict minimum | Special appliances Water heater Class II luminaires | ||
| Zone 3 | 21 | Only socket-outlets protected by :
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| Swimming baths (section 702) |
Supplementary equipotential bonding in zones 0, 1, and 2 |
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| Zone 0 | SELV 12 V | 28 | Class II limited to strict minimum |
Special appliances | ||
| Zone 1 | 25 | Class II limited to strict minimum |
Special appliances | |||
| Zone 2 | 22 (indoor) 24 (outdoor) |
Only socket-outlets protected by :
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| Saunas (section 703) |
24 | Class II | Adapted to temperature | |||
| Work sites (section 704) |
Conventional voltage limit UL reduced to 25 V | 44 | Mechanically protected |
Protection by 30 mA RCDs | ||
| Agricultural and horticultural establishments (section 705) |
Conventional voltage limit UL reduced to 25 V Protection against fire risks by 500 mA RCDs |
35 | Protection by 30 mA RCDs | |||
| Restricted conductive locations (section 706) |
2x | Protection of:
- SELV or
- By SELV
- SELV - 30 mA | ||||
| Fountains (section 702) |
Protection by 30 mA RCDs and equipotential bonding of all exposed and extraneous conductive parts |
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| Data processing (section 707) |
TN-S system recommended TT system if leakage current is limited. Protective conductor 10 mm2 minimum in aluminium. Smaller sizes (in copper) must be doubled. |
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| Caravan park (section 708) |
55 | Flexible cable of 25 metres length | Socket-outlets shall be placed at a height of 0.80 m to 1.50 m from the ground. Protection of circuits by 30 mA RCDs (one per 6 socket-outlets) |
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| Marinas and pleasure craft (section 709) |
The cable length for connection to pleasure craft must not exceeded 25 m | Protection of circuits by 30 mA RCDs (one per 6 socket-outlets) |
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| Medical locations Group 2 : Operating theatres and similar (section 710) |
IT medical system equipotential grouding, limited to one operating theatre and not exceeding 10 kVA |
Only magnetic protection for the primary of LV/LV transformer. Monitoring of secondary loads and transformer temperature |
Protection of circuits by thermal-magnetic protection only. One to three per circuit. | |||
| Medical locations Group 1 : Hospitalization and similar (section 710) |
TT or TNS | Protection by 30 mA RCDs |
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| Exhibitions, shows and stands (section 711) |
TT or TN-S systems | 4x | Protection by 30 mA RCDs |
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| Balneotherapy (cure-centre baths) |
Individual: see section 701 (volumes 0 and 1) Collective: see section 702 (volumes 0 and 1) |
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| Motor-fuel filling stations |
Explosion risks in security zones | Limited to the necessary minimum | ||||
| Motor vehicules | Protection by RCDs or by electrical separation | |||||
| External lighting installations (section 714) |
23 | Protection by 30 mA RCDs |
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| Mobile or transportable units (section 717) |
The use of TN-C system is not permitted inside any unit | 30 mA RCDs must be used for all socket-outlets supplying equipment outside the unit |
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Fig. Q20: Main requirements prescribed in many national and international standards
