Grouping Air
From Open Electrical
Grouping in Air
Arrangement (installation method) | Number of multi-core cables or single-core circuits | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 12 | 16 | 20 | |
Bunched in air, on a surface, embedded or enclosed (A-F) | 1.00 | 0.80 | 0.70 | 0.65 | 0.60 | 0.57 | 0.54 | 0.52 | 0.50 | 0.45 | 0.41 | 0.38 |
Single layer on floor or wall (C) | 1.00 | 0.85 | 0.79 | 0.75 | 0.73 | 0.72 | 0.72 | 0.71 | 0.70 | 0.70 | 0.70 | 0.70 |
Single layer multicore on a perforated horizontal or vertical cable tray system (E-F) | 1.00 | 0.88 | 0.82 | 0.77 | 0.75 | 0.73 | 0.73 | 0.72 | 0.72 | 0.72 | 0.72 | 0.72 |
Single layer multicore on a cable ladder system or cleats etc. (E-F) | 1.00 | 0.87 | 0.82 | 0.80 | 0.80 | 0.79 | 0.79 | 0.78 | 0.78 | 0.78 | 0.78 | 0.78 |
Grouping in Ground
For cables laid in ducts:
Number of cbles or circuits | Multi-core cables | Single-core cables | ||||||
---|---|---|---|---|---|---|---|---|
Clearance between ducts | Clearance between ducts | |||||||
Touching | 0.25 m | 0.5 m | 1 m | Touching | 0.25 m | 0.5 m | 1 m | |
2 | 0.85 | 0.90 | 0.95 | 0.95 | 0.80 | 0.90 | 0.90 | 0.95 |
3 | 0.75 | 0.85 | 0.90 | 0.95 | 0.70 | 0.80 | 0.85 | 0.90 |
4 | 0.70 | 0.80 | 0.85 | 0.90 | 0.65 | 0.75 | 0.80 | 0.90 |
5 | 0.65 | 0.80 | 0.85 | 0.90 | 0.60 | 0.70 | 0.80 | 0.90 |
6 | 0.60 | 0.80 | 0.80 | 0.90 | 0.60 | 0.70 | 0.80 | 0.90 |