There are different standards such as HD (harmonisation document), EN (european standard), NEN (Dutch standard) or IEC (international standard).

Only when it is adopted by a legislator does it become an obligation.

By way of explanation, a law is in principle freely accessible, and can therefore be viewed without cost.

Through the Building Decree 2012 (legal requirements for construction works), the NEN1010 (currently the 2015 version) is designated. Not the entire NEN1010 is designated but only the provisions dealing with electrical safety. All cross-references from NEN1010 are not included. 

A standard may also be included by a client in the contract documents (under private law) and application of the relevant standard will then be compulsory in its entirety.

The NEN 1010 is a guideline and therefore not a law. That is why the NEN institute can charge money for it. One is basically free to apply this standard or not.

But, in the 2012 Building Decree, and it is included in the law, the electrical safety level of NEN 1010 must be achieved. To achieve that level, the easiest way to do so is to design and fit the installation according to NEN 1010.

But there is more. Every installation or good must have a CE mark. In the electrical field, this is the low-voltage directive, issued by the EU. 

This low-voltage directive refers to the IEC 60364. It is up to the EU countries to implement it in their own countries. In the Netherlands, this was done by means of the NEN 1010. NEN 1010 is therefore a copy of IEC 60364. The article numbers (provisions) therefore correspond. 

In neighbouring countries, too, the article numbers of the national standard in force there are identical to IEC 60364. This facilitates free trade.

Incidentally, each country has additional additions, and is indicated in NEN 1010 by an n (in NEN1010:2020 by 'nlb'). 

By the way, the reason for such additions is unclear, is one country better than another?

The designated EN standard 50575 is very clear on this. For cables, the CPR applies to building-related cables for the purpose of the building. These are cables in or on the building (structure). 

A ground cable lying in the ground is not part of this, but as soon as the cable enters the building (structure), one must comply with the Dutch Buildings Decree 2012 or NEN8012:2023 PART 1. 

If a cable then enters the distribution box via the crawl space, an Fca or Eca fire class is sufficient.

Yes, but in many cases the surface area of cables is quite small compared to walls, ceilings and floors. In many cases, according to the building code, if the surface area is less than 5%, further fire resistance is not required. 

But note that this 5% must then include any other combustible materials in the room in question, such as window frames etc. 

Because of this last addition, the 5% exemption does not often apply.

From July 2023, NEN8012:2015 has been replaced by NEN8012:2023, which consists of two parts. The NEN8012: Part 1 is based on the legal requirements from the BUILDING DECREE 2012 and which must be met. This part deals with preventing the spread of fire and smoke and preventing casualties.

Yes, for example for cables in lifts, cables with function retention. Or cables that do not belong to building components. 

According to the 2012 Building Decree, only cables belonging to building components should have a CPR fire classification

That is certainly possible for low voltage. For high voltage, consultation with the cable manufacturer is required. The reason for this is that small microscopic air bubbles in the insulation can grow due to the continuous equal direction. This effect does not exist with alternating voltage.

If you use a fuse there are no differences, at most that the voltage must be suitable, but when using circuit breakers it does matter. Automata are calibrated at 50 Hz. A correction is therefore necessary at a lower or higher frequency. It is best to use a cable calculation program that corrects for other frequencies.

According to the IEC 60853 standard, it is stated that a cable is not continuously loaded, but such as for a drinking water pump or a PV installation, but for a short period of time. then a factor of 0.8 can be applied, so that a thinner cable will suffice. The background to this is that a cable that heats the ground for a while, gives the ground time to dissipate the heat. The difference with cables in a ladder track is that ground can absorb heat and air cannot.

The simple answer is to measure is to know. In practice, for the Netherlands, where the groundwater level is quite high and there is relatively sufficient rainfall, 1 Km/W will suffice. At a humidity of less than 0.1 m3/m3 the resistance increases.

Clay in particular is a point of attention. A cable that becomes warmer than 50°C will cause the soil to dry out. This dehydration increases the thermal resistance and the cable cannot lose its heat. With clay you get the effect that the clay is baked and an irreversible situation occurs. The thermal resistance can increase to as much as 4 or 6.

Aluminum cables are increasingly used. Especially now that the copper price continues to rise.

Certainly the cross-section must be recalculated. After all, the resistance of aluminum is higher than that of copper. And because more resistance causes more heat in the cable, after all the heat generated is I^2 x R, so less current can pass through it. The voltage loss also increases, but because the cable already becomes thicker due to the heat, the cable will not also become thicker as a result of the maximum voltage loss. This also applies to the calculation of the maximum length for a short circuit.

Certainly, and not unimportant. Special copper-aluminum connection terminals must be used. If this is not done, the aluminum will be 'eaten'. It should be noted that the expansion coefficients of aluminum are different from copper. With many temperature variations, checking the connection flags is necessary. It is also advisable to check the connections a few months after installation.

Aluminum cable is also possible as a flexible cable (class 5).

Even that. Because aluminum is lighter in weight, a lighter construction of the cable support such as ladder tracks or cable ducts will suffice.

The same physical properties apply to a cable on a ship or in a building on land. The current carrying capacity tables in NEN 1010, and therefore also in IEC 60364, simply apply. However, it should be noted that on ships a higher ambient temperature is usually assumed and several cables next to each other. The current carrying capacity tables for shipping therefore seem different than for land, but if these are converted for 20 degrees C, they are again the same tables as in IEC 60364.

Yes, on ships a correction can be applied according to the ship standards if cables are not continuously loaded. In software to calculate cables you can specify a service time and a waiting time.

That certainly matters. If you use circuit breakers, these must be corrected for the higher frequency in the cable calculation. After all, automatics are calibrated for 50 Hz. In addition, the skin effect starts to play a role from a certain cross-section.

Does it make any difference to the cable cross-section if I use a larger fuse?

Unfortunately yes. A gG cartridge differs slightly per manufacturer and sometimes also per construction type. For some manufacturers, a gG characteristic is the same for different construction types.

It is best to choose single-core cables, laid against each other and laid flat.

That is not that difficult, you choose single-core cables on clamps if it concerns loose cores on switches, or single-core cables in a duct if it concerns the wiring in the wire duct. For the latter, consider the factor for the number of cables next to each other

Cables are not always UV resistant. Particularly the usual gray cables. A regular check of cables that are always exposed to the sun is necessary after a few years.

IEC 60364 (copy in NEN 1010) contains current carrying capacity tables for cables. However, this is limited to XLPE, PVC or EPR insulated cables. Nothing has been included for other materials. There are software packages that can also determine the cross-section for other cable materials based on the thermal properties and temperature range.