Hi 7another4!
Thanks for the addresses on behalf of all participants of this thread.
However, the duct vs direct buried could be discussed. In the first post of this thread ahandle was connecting a transformer with switchgear. I would use rather cable bus than duct but he may have a different...
Kiribanda, as you noticed we are talking about the induced current. A magnetic field is always present when current flows through a conductor no matter what material is made of. If an another closed circuit conductor is placed in this field an electrical current will be induced when the magnetic...
It doesn't make any sense to me to build a duct with several conduits to run 3.3kV cables. The duct bank itself will cost many times more than the cables. In my opinion, for this purpose there are cable ducts that are designed by cable specialists that have available engineering calculation...
If the system is important the BJC advise is what you should use. It is dielectric and the information can be transfer over long distances 24/7. Off course all perks of other older type equipment are included. However, it doesn't come cheap but is very reliable in electrical field environment.
I would suggest that you consult manufacturers of "cable bus". I do not know the details of your intended installation but installing them all together in one conduit does not seem to be a good idea to me. Note that the all cable metallic parts subject to mutual induction (no matter how long)...
inclebob, every voltage AC, DC, VLF (technically it is AC) ... that is applied to the insulation will have some detrimental effect on it. If the voltage is high enough to break the insulation ... this is the outcome of the test.
The purpose of the "HI-POT" is to check if the cable insulation is...
Gentlemen, the thread started with the post asking for cable calculation not testing and we should come back to it.
While calculation of the cable ampacity is not a new problem its modelling is IMHO the biggest obstacle as well as understanding the cable working conditions. The MV calculations...
I do not have too much experience with pulling low voltage cables but there are three conditions that should be looked after during any pull.
1. maximum pulling tension
2. minimum bending radius (as the multiplication of the overall diameter not individual conductors)
3. maximum sidewall...
I know that it is difficult to install such conductor but it is not impossible. The bending radius is usually 15 x cable diameter. If 1000mm2 the cable diameter is ~41mm so the radius is say 700mm.
Regarding ampacity - I would say in reverse: that the ampacity of a circuit does not double when...
I think that using 1000mm2 per phase gets better current density than 3x400mm2 = 1200mm2 for the same load. In my opinion using multi-cables per phase circuit produce more copper than bigger conductors. It is easy to check by using IEC standard. I have seen 2000mm2 cables being installed.
Gentlemen, all "withstand" tests are of "kill or survive" type tests. They give very little (if any) information about any cable conditions. The discussion among cable engineers and scientists is ongoing for decades. Fortunately, with the development of power electronics we have a better chance...
igg1966, the NA does not differ from other parts of the world. Current flows in the same direction so whatever you calculate in Spain is applicable behind the big puddle called Atlantic. The web pages given by others could be a great help as other European cable manufacturers. There are...
Jareb, I do not know rationale behind the decision of using 400mm2 cables. I would rather use 1000mm2 single conductor per phase. If, however, you have to use 3 conductors per phase there is something called "cable duct". If your voltage is 600V (I assume based on cables you mentioned) the cable...
