Current Ratings Correction Factors on Cable Laying Conditions

Fig- Crossectional View of XLPE Power Cable

Continuous Current Ratings Correction Factor Varies on Different Cable Laying Conditions

Today we will try to find how various laying conditions of cable become a factor for current ratings of XLPE insulated copper conductor power cables, means depends on cable laying various condition current carrying capacity increase or decrease. Such as various ambient air temperatures, various ground temperatures, various thermal resistivity of ground and various depth of cable laying is the factor for cable current ratings. 

In our previous post Continuous Current Ratings of XLPE Insulated Power Cable we try to find the current carrying capacity for various sheathed like Aluminium, Lead or Copper wire shield XLPE insulated copper cable.

To determine current capacity for the various laying conditions than those indicated on the every table, multiply table values by the correction factors shown below.

Correction Factors for Various Ambient Air Temperatures

Air Temperature(oC)	20 oC	25 oC	30 oC	35 oC	40 oC	45 oC	50 oC
Rating Factors	1.2	1.16	1.10	1.05	1.0	0.94	0.88

Air Temperature(oC)	15 oC	20 oC	25 oC	30 oC	35 oC	40 oC	45 oC
Rating Factors	1.08	1.04	1.00	0.96	0.91	0.87	0.83

Thermal Resistivity of Soil (oCm/w)	0.7	1.0	1.2	1.5	2.0	2.5	3.0
Rating Factors	1.14	1.00	0.93	0.84	0.74	0.67	0.61

Correction Factors for Various Ground Temperature Correction Factors for Various Thermal Resistivity of Ground
Correction Factors for Various Depth of Laying

Sponsored:

Depth of Laying (m)	Rating Factor
0.50 ~ 0.70	1.09
0.71 ~ 0.90	1.05
0.91 ~ 1.10	1.03
1.11 ~ 1.30	1.01
1.31 ~ 1.50	1.00