Shower circuit breaker, installation tips!

Do you know what the correct circuit breaker to use in your shower? If you don’t know how to choose a shower circuit breaker, be calm because that’s what we’re going to talk about in this article. Come on guys!

Directly we received many doubts about the dimensioning of circuit breakers, but without doubt the dimensioning of circuit breaker for shower is the biggest doubt that we received. Having these doubts is normal because the shower is one of the most powerful appliances in residential installations.

What type of circuit breaker to use in the shower?

The circuit breaker is an electromechanical protection device that protects electrical installations, automatically tripping when it identifies an electrical current that exceeds the circuit breaker’s electrical current rating, thus preventing the passage of energy to the circuit loads, preventing other loads and the circuit is damaged.

There are several types of circuit breakers for different applications such as molded case open circuit breaker, DDR, DIN, NEMA etc. But the correct circuit breaker to use in the electric shower must be the mini circuit breaker that complies with DIN (Deutsches Institut für Normung) or the famous black circuit breakers, which complies with NEMA (National Electrical Manufacturers Association).

The DIN and NEMA circuit breakers are the most used in residential electrical installations, even though NEMA is being replaced by DIN, both offer thermomagnetic protection for overload and short circuit.

DIN mini circuit breaker and NEMA circuit breaker.

The differential of the DIN mini circuit breaker is the curves, which is a feature not available in the NEMA circuit breaker, for this and other reasons DIN is gaining market share. The curves of the DIN mini circuit breaker define the applications of the circuit breakers, that is, the loads that will be connected to them.

The breaker break curve is the time that the breaker can withstand a current above the rated current for a given time. The circuit breaker curves are B, C and D, due to the electrical current measurement unit being in ampere (A), there is no characteristic curve with letter A, for organization reasons.

If you choose a DIN circuit breaker to use in the electric shower, you must use a circuit breaker with the correct electrical current for the shower connected to the circuit breaker and which has the B curve, the curve is described next to the rated current of the circuit breaker.

Where the curve is described, side of the circuit breaker rated current.

If you prefer to opt for the black NEMA circuit breaker, just look at the correct electric current for the electric shower, as there is no curve in the NEMA circuit breaker.

A very important point that should be noted is the type of energy supply in your home, as there are different types of supply defined by the energy utility, this directly interferes with the circuit breaker. The following table indicates the levels of secondary electrical voltages provided by the electricity concessionaires in accordance with ANEEL standards.

Secondary electrical voltage levels according to ANEEL standards.

DIN and NEMA circuit breakers can change depending on the supply, as both have three different types, which are monopolar, bipolar and tripolar.

The monopolar circuit breaker is used in installations and circuits that have a single phase conductor. The bipolar circuit breaker is used in circuits or installations that have two-phase conductors. The three-pole circuit breaker is used in installations and circuits with three-phase conductors.

Monopolar, bipolar and tripolar circuit breaker.

How to know the right chain?

The correct electrical current is written on the shower body itself or on the packaging in which the shower came. But, if the package and shower do not inform the electric current, in some cases it is possible to calculate the current using a simple ohm law .

Formulas using the electrical quantities of ohm’s law.

To be doing calculations we need two electrical quantities, which is the power and the electrical voltage of the shower, without this two pieces of information it is not possible to dimension the circuit breaker correctly.

If we consider a 220V installation and an electric shower that has an electrical power of 5,500W, just divide the power by the voltage and the electric current of the shower using the ohm law is 25A, so our circuit breaker must have the current electric current as close to 25A as possible.