Watt, Volt and Ampere during lamp installation
Before installing a lamp, you should know 3 basic concepts of electrical engineering.

Have you ever asked yourself what exactly “watt” or “volt” means? Or what a neutral conductor is? When installing a lamp, you will encounter these terms and you have to deal with them. Sometimes more, sometimes less, depending on the complexity of the lamps.

In this article, we deal with the definition of these terms and try to explain them very easily with many examples. We limit ourselves to the concepts of electrical engineering, which could occur in the course of typical lighting installations.

The definition of watt, volt and ampere

Watt: Watt is the unit for the power. It is determined by the energy conversion of a device per time span. So household appliances like a hair dryer work with about 1600W or a water cooker with up to 2000W. The longer these devices are in operation, the more power they consume. This power can be calculated: Watts = Volts x Ampere

Volt: Volt is the designation for the electrical voltage, e.g. from a power grid. This describes how much energy is in the electrons of the line. A typical socket in Germany supplies alternating current with a voltage of 230V.

Ampere: also called “amps” indicates the current. This is the value that indicates how many electrons flow through a cable during a given period of time. This value is rarely encountered by an ordinary consumer. The fuse box of a house has e.g. fuses with 16 amps.

If electricity was water…

An example that is often referred to as the components of current is the following:

Electricity “flows” as well as water. So imagine the current as water. The volt (V) denotes the voltage of the current. The voltage (P measured in volts) is the gradient with which the electrons flow through a cable. This is comparable to the slope of water in a water pipe.

Ampere (A) on the other hand, is the measuring unit for the current intensity. This is comparable with the thickness of the water line: if the line is very thick, much more water can flow than with a thin line. As a result, the water has more power. The amperes and volts are the same as the water pressure and the amount of water flowing through. For example a high pressure cleaner can remove dirt from aluminum rims, because it builds up pressure but it would not be suitable for a larger fire.

Watts, amps and volts using a hydroelectric power plant clearly explained.

Another example to illustrate this is the comparison with a hydroelectric power plant. A hydroelectric plant can produce more power (watts) the more water flows in and the higher the gradient (voltage measured in volts) with which the water hits the turbines. If there are many large stones in the river bed and slow down the flow of water, the power would be correspondingly reduced. The stones correspond to the electrical resistance, measured in ohms (Ω). The total water quantity represents the current measured in amps (I).

The more cross-section the river bed has on the way into the hydroelectric power plant, the more current can flow through this river. A larger cable section also means that the cable can withstand more current and can carry more power. It follows that the power (P) is dependent on the voltage (U) and the current (I). The formula for the calculation of Watts is:

The formula for calculating watts in electrical engineering.

Who does much, consumes also a lot. A hair dryer is with about 1400 watts a real power carrier. But how much does a hair dryer use when it does so much? The consumption of the hair dryer is measured in kilowatt hours (kWh).

The abbreviation kWh sure you know from your electricity bill. To explain what plays into KWh, the individual factors watt, hour and kilo have to be explained. 1400 Watts correspond to the performance of the hair dryer. In order to correctly calculate the consumption, the correct question is: How long does the hair dryer blow? The consumption is always related to a period.

Therefore, the performance is measured with respect to the time (in the case, one hour) for the hair dryer. A watt-hour (Wh) is the consumption that a device with a power of 1 Watt consumes within an hour. In the household, there are only a few devices with only one watt power.

The hair dryer with its 1400 watts consumes in an hour logically 1,4 kWh. The word “kilo” comes from the Greek language and means nothing more than “a thousand”. It is added to not have to call endless high numbers. One kilogram is a thousand grams. And so 1000 watt-hours are 1 kilowatt-hour (1000W = 1kWh).

Cable colors in Germany

If, for example you want to install a lamp on the ceiling, you must connect the wires that come from the ceiling with the wires of the lamp in a correct polarity. This means the same colors must be connected to each other. We have a small set up, which allows you to easily assign the cable colors.

What colors do the power cables have in Germany? We show this in this overview from our article about Watt, Volt and Ampere.
In the case of old buildings, the colors of the cables may be different and differ from those of today's electrical cables. For example by 1965, the gray neutral conductor and the protective conductor were red.
Christine HillerLighting expert at Houzz & HQ Designs

Caution: Before working with electrical appliances, always check the relevant safety regulations. This includes the switching off of the fuse and the control with the phase tester or a voltage tester. These are subject to special safety requirements according to EN 61243-3 (VDE 0682-401: 2011-02) and are divided into measurement categories (CAT I to IV). In general, it is not only recommended for your health’s sake, but also often due to possible loss of warranty in such matters to consult an electrician.

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