Electrical Engineers And Master Electricians EEAME Portal

...references, ebooks, standards and tutorials

  • Increase font size
  • Default font size
  • Decrease font size

Voltage Drop Calculation

Article Index
Voltage Drop Calculation
Page 2
All Pages
Voltage drop

This article is the first of a series in the selection of electrical cables.

Cable selection is an important part of electrical installation design. Selecting the correct size of cable could lower initial cost, lower operating cost, better voltage regulation notwithstanding the safety factor.

Cable parameters are provided in values per unit length, usually ohms per kilometer(Ω/km) for IEC or miles(Ω/mi) for North American Standards.

The following table illustrate the typical parameters for industrial cables



Table 1. 600/1000 V. Cu/EPR/CSP/GSWB run on open trays or enclosed in air. 1 to 6 x single, 3 or 4 cores
Nominal
conductor
area (mm2)
Single cores
in trefoil
3 cores Approximate
armouring
resistance
Resistance
at 90oC
(ohm/km)
Reactance
at 50Hz
Resistance
at 90oC
(ohm/km)
Reactance
at 50Hz
GSWB at 60oC
3–4 cores
(ohm/km)
1.5 15.6 0.185 15.6 0.118 46.2
2.5 9.64 0.173 9.64 0.111 51.3
4 5.99 0.163 5.99 0.108 60.3
6 3.97 0.153 3.97 0.105 30.5
10 2.35 0.148 2.35 0.0983 36.7
16 1.48 0.134 1.48 0.0933 23.1
25 0.936 0.125 0.936 0.0892 28.1
35 0.674 0.121 0.674 0.0867 10.43
50 0.499 0.118 0.499 0.0858 11.81
70 0.344 0.112 0.344 0.0850 13.61
95 0.271 0.108 0.271 0.0825 10.87
120 0.214 0.106 0.214 0.0808 11.92
150 0.175 0.105 0.175 0.0808 7.38
185 0.140 0.105 0.140 0.0808 8.15
240 0.108 0.103 0.108 0.0800 8.94
300 0.087 0.101 0.087 0.0800 10.10
400 0.069 0.0992 0.069 0.0795 10.00


 

Design Stages

Successful projects were not developed overnight. They have undergone through several stages. Missing any one stage may have caused disastrous effect on the projects causing failure.

Conceptual Design
To develop your project ideas into a more tangible perspective.
Front End Engineering and Design (FEED)
To explore possibilities to enable better control on the outcome of ideas, getting the final result without delay but more importantly without overshooting your budget.
All ideas need to be developed at this stage of the project.
Detail Design
The final stage of the design aspect of your project. Only minor, unforeseen and uncontrollable by the project team need to be implemented at this stage.
Injecting radical changes at this stage could mean redevelopment of the project concepts leading to project delays and budget overshoot.

We could offer the Electrical Engineering aspect of your project ideas. If you want to seek our help, contact us at [email protected].