The application CableApp has been developed to meet user requirements by helping to select the most suitable Prysmian cable. The data and results are only informative.
The energy saving calculation is made with factors that we have defined, entered or make available. All calculations that include potential monetary or CO2 savings in connection with reduced power consumption are for guidance only. Prysmian Group assumes no responsibility for errors in calculations.
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The CableApp uses correction factors defined according to IEC 60364-5-52. This makes it possible to tailor calculations
according to the extension method, installation details and cable specifications.
The following values are used as a basis for calculations, these are taken from a selection of tables in IEC 60364-5-52
and are as follows:
| Parameters | Value |
| Temperature in air | 30°C |
| Temperature for energy saving calculations | 20°C |
| Temperature in soil/trays | 20°C |
| Standard installation depth for cables on tray | 0.7m |
| Resistance in soil (for cables on tray) | 2.5 Km/W |
Energy efficiency is a pressing issue that is increasing more important each year. The electricity bill has become a major
item on the budget that is closely watched. Turning off the lights and lowering the heat is half, but an initial
energy-saving investment that pays off over a few years - can ensure a long-term and tangible financial return.
A larger cable cross-section will be more expensive and a clear investment. But the effects will be lower resistance and
energy loss in the cable at the same voltage, which can be converted to:
CableApp is Prysmian Group's free smartphone app for calculating and selecting cable dimensions for any type of installation up to 1 kV. All calculations state the annual savings in kroner and CO2 emissions by using the best or larger cross-sectionkd rather than the essential cross-section for a given installation.
With the traditional calculation method, where the smallest cable cross-section is selected, the lowest installation cost is ensured. However, this calculation does not take into account the annual or total lifetime cost for an installation.
The goal of a total calculation is to minimize the lifetime cost for an installation and to reduce emissions due to losses in the cable.
When calculating with CableApp, you can change the price of electricity in your local currency per. kWh under the menu point ”Settings”, to obtain a personalized energy efficient calculation.
| Electricity per kWh | 2,75 kroner | Can be changed under ”Settings” |
| Average consumption load | 40% | Can be changed under ”Settings” |
A cable does not have the same load at all times, as power consumption varies throughout the day and year. The app can therefore calculate with a factor for the average consumption load (aC).
| - | 100% | (full capacity) |
| - | 75% | (industry) |
| - | 60% | (common area) |
| - | 40% | (housing) |
| - | X% | (other) |
According to Joule’s Law, a conductor carrying electricity will always generate heat or thermal energy. If the cross section of a cable is increased the effect will be a lower resistance (R) in the cable at the same voltage as well as a lower energy loss (EP).
This energy efficiency can be converted into a monetary savings and reduced CO2 emissions. The thermal energy produced in a cable is given by the following formula:
Ep = n/c x R x L x I² x t/1000
| Ep | produced energy (energy loss in heat) kWh |
| n | number of conductors (2 for single-core) |
| c | number of cables per phase |
| R | conductor resistance Ω/km |
| L | cable length in km |
| I | current load A |
| t | time in hours |
| aC | average consumption |
The calculation uses a factor for the average consumption load (aC) corresponding to a percentage of the current load (l). The energy saving (EA) by increasing the cross section and reducing the resistance of the cable from (R2) to (R1) will thus be:
EA = n/c x (R1-R2) x L x (% aC x I)² x t/1000
After the energy efficiency in kWh has been calculated, the economic savings in your local currency as well as the reduced CO2 emissions can be calculated.
The CO2 factor is pre-set to 0.14 kg CO2 / kWh according to the Danish Energy Agency’s figure for 2021 and can not be changed in the app. This factor indicates the average CO2 emission in kg per kWh in relation to Denmark’s annual energy mix.
Below is a demonstration of an energy saving calculation using the above formulars and definitions:
Application: 1 kV, in free air method E, single-circuit
Cable type: RZ1-K 0,6/1 kV Dca
System: 3-phase, length 130 meters, current load 268 A, correction factor 1
Result: Essential cross-section 95 mm² and best cross-section 120 mm²
To calculate the energy saving by increasing the cross section, the formula EA is used, which calculates the difference in conductor resistance (R1-R2) where R1 = 95 mm² and R2 = 120 mm². All energy-saving calculations will be a conservative estimate of the actual saving, as all calculations use a conductor resistance at an ambient temperature of 20°C for all cross-sections.
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For this calculation, the annual consumption in time (t) is set to 365 days x 24 hours equal to 8,760 hours.
The calculation uses an average consumption or load (aC) corresponding to 40% of the current load (l).
Based on this, we can calculate the annual saving by increasing the cross section from 95 mm² to 120 mm² as follows:
Ovenstående informationer er vejledende for beregningerne, der er foretaget i CableApp for at finde energibesparende løsninger.
Beregningerne foretages med faktorer, som vi har opstillet, indtastet eller stiller til rådighed. Alle beregninger, der inkluderer potentielle besparelser på CO2 eller kroner i form af reduceret strømforbrug er kun vejledende. Prysmian Group påtager sig intet ansvar for fejl i beregningerne.
