Oman Low-Voltage-Power-and-Control-Cables

TABLE - 64

( FOR INSTALLATION IN AIR ONLY) GROUP RATING FACTORS FOR GROUPS OF MORE THAN ONE MULTI-CORE CABLE IN AIR - TO BE APPLIED TO THE CURRENT-CARRYING CAPACITY FOR ONE MULTI-CORE CABLE IN FREE AIR Number Number of cables of trays 1 2 3 4 6 9 1 1.00 0.88 0.82 0.79 0.76 0.73 Method of Installation

Touching

2

1.00

0.87

0.80

0.77

0.73

0.68

3

1.00

0.86

0.79

0.76

0.71

0.66

Cables on perforated trays

Spaced

1.00

1

1.00

0.98

0.95

0.91

-

2

1.00

0.99

0.96

0.92

0.87

-

3

1.00

0.98

0.95

0.91

0.85

-

Touching

0.72

1

1.00

0.88

0.82

0.78

0.73

2

1.00

0.88

0.81

0.76

0.71

0.70

Cables on vertical perforated trays

0.91

1

1.00

0.89

0.88

0.87

-

Spaced

2

1.00

0.91

0.88

0.87

0.85

-

0.78

1

1.00

0.87

0.82

0.80

0.79

Touching

2

1.00

0.86

0.80

0.78 0.76

0.73

3

1.00

0.85

0.79

0.76 0.73

0.70

Cables on ladder supports, cleats, etc

1

1.00

1.00

1.00

1.00 1.00

-

Spaced

2

1.00

0.99

0.98

0.97 0.96

-

3

1.00

0.98

0.97

0.96 0.93

-

Note 1: Values are given for vertical spacings between trays of 300 mm and at least 20 mm between trays and wall. For closer spacing, the factors should be reduced.

Note 2: Values are given for horizontal spacing between trays of 225 mm with trays mounted back to back. For closer spacing, the factors should be reduced.

50 MKK XXS002-02/01-12-2014

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