Cables

Cables are very important when we want to build any project either it is small or large. Choosing a cable is very difficult when your budget is limited. And it is important that what type of project you want to do, you don't want to buy co-axial cables for solar project which make no sense at all.if you want to do a solar project you have to buy solar cables and to do that you need to know how to choose it.

 

To choose any cables we need to have few things in mind : 

• Project Cost 
• Project Location (Distance, Temperature )
• Project Parameters ( Voltage, Current etc).
• Project Size.

  Now let consider all the objects for a better outcome.

• Project Cost : If you are a professional engineer then it is compulsory that you keep your money safe otherwise you can't pay the bills 😜. So better consider it before you are serious, we have to calculate few things to understand that how much it can cost. (Aujubillah)
• Project  Location : Location is very important, you should be subtle on this because every inch is costly. The distance between the Solar System to your load can be expensive if you allow it, so measure it empirically because cable cost is based on its length and lower the better. (Alhamdulillah ). And you also have to keep the location temperature in mind  because it also decrease the efficient of a cable conductivity, so make sure your project is in ambient temperature and you can save more money.
•  Projects Parameters : The parameters are actually related with the law of resistance R ∝ L/a,  which is also can be written R = ρ (L/a).  We buy the cables according to their parameters like resistance, current and voltage it can bear. There are also question of Temperature factor , voltage drop or the system (1, or 3- Phase). In normal solar system like solar home system most of them are 1-pahse but if it is grid like solar grid then we need to consider 3-phase cables.
•  Project Size :  Project Size is also huge property for any projects. Bigger the project bigger the cost, and choosing cables become more difficult as the system is so complicated.In big projects you have to be more subtle because the inches of cables for recklessness will come up with much more payment.

How To Choose Cables For Projects :

To Choose a cable for your projects you need to calculate some parameters ,follow the following rules to select your cables...

Rule 1 : First calculate the projects load (Load Info), then add up more 20% extra load to the calculation for future connection in case we need extra load in future. Then calculate overall system load and divide with system voltage, so you get the cable current.

Example : If a System has 5200W of Load Then Take 20% of it (20% of 5200)=1040W, now add up with the system load = (5200+1040) Watt = 6240 Watt which is the project load, now if the system voltage is 230V, then the cable current will be = (6240/230) Amp = 27.1 Amps. Now you can check this parameter and find out the cable. As the current is 27.1 Amps  if you check the data table for copper wire 2-core cable then this will be 7/0.915 which current ratings is 28Amps. Now go for Rule 2.

Rule 2:   After you find the cable  now check for temperature factor for that cable which is necessary  as for temperature has effect on conductivity. At higher temperature, conductivity of a cable will decrease. Lets assume the ambient temperature for the project is 35℃, and at this temperature the temperature correction factor is = (254.5/234.5+t) = 0.944. And the conductivity of the 7/0.915 cable at 35℃ will be (28x0.944)= 26.4 Amps, which means at 35℃ temperature this 7/0.915 cable will not able to carry the load current which is 27.1 Amps > 26.4 Amps (Auzublillah). So you have to choose the next one for your project which is 7/1.12 which can carry up to 36 Amps and at 35℃ this can carry (36x0.944) = 33.9 Amps > 27.1. Now go for Rule 3 :

Rule 3:  According to the IEEE- Rule for conductors  at any point between power terminals the voltage drop should not be greater than 2.5% of the supply voltage. As an example if you need a cable which is 100m long and the supply voltage is 230V then the voltage drop should not be exceed (2.5% of 230V) = 5.75V. If your selected cable doesn't comply with it then change it.

So the summary is you have to go through all the above process to accomplish a better and cost effective and safe project. I hope and pray that you guys understand and rate this article and use this concept for safer and cost effective projects.

Hope You Like This Post  (Jajakallahu Khair)