F.A.Q. return

No. This nominal gauge must not be confused with a geometric gauge (the cross section area).

The nominal gauge is linked to its maximum value of electrical resistance at 20º C (.../km) and, in many cases; it is also complemented by other characteristics, such as the minimum quantity of wires or the maximum gauge of wires it is made from.

The nominal gauge is defined in square millimeters, based on the IEC standard (International Electrotechnical Commission), the specific Brazilian standard is NBR NM 280, based on the conductor classification.

It depends on the use. The only difference is flexibility, as the current capacity is the same, for example, a 1.5 mm² wire, 1.5 mm² cable, or 1.5 mm² flexible cable have the same current conductive capacity.

Then to summarize, the current capacity is the same for all the nominal gauges, regardless of the class of conductor.

The preference of the designer or installer will define the class selection.

Yes, there is. Light blue must be used for neutral conductors, and green or green/yellow for grounding conductors, also known as "Little Brazil" as they are the Brazilian national colors.

The other colors may be freely chosen. This rule is defined by the NBR 5410 Brazilian technical standard - Low voltage electrical hookups.

Based on the NBR 5410 technical standard, the minimum gauge for electrical outlets for general use is 2.5mm² and for lighting circuits, it is 1.5mm².

There is no problem in using a larger nominal gauge; but it just cannot be smaller.

The class defines if the conductor is a wire, (rigid) cable, or a (flexible) cable.

Class 1 is applied to solid wires and class 2 is applied to rigid cables.

Classes 4 and 5 are applied to flexible cables, as class 5 is more flexible than class 4, however the difference is not always noticeable.

Permanent operation: 70°C

Overload operation: 100°C

Short circuit operation: 160°C

AWG means (American Wire Gauge) which is the standardized American scale. Use the conversion table below to convert to the AWG standard to mm², which then converts to the EB-98 standard, which has already been canceled and substituted by the NBR NM 280 standard, which has become the currently applied standard, both issued by ABNT (the Brazilian Standardization Entity).

This table is not valid for conversions based on the NEC table - National Electrical Code, which complies with the American standard.

The table below was taken from the NBR 5410:2004 standard, which describes the current capacity in amperes (A), for PVC insulated copper conductors (70°C), based on the B1 and B2 reference methods.

B1: insulated conductors or unipolar cables in round conduits embedded in brickwork.

B2: multipolar cable in round conduits embedded in brickwork.

The voltage drop cannot be over 4% in a terminal circuit, however in higher voltage equipment with a higher initial voltage, during the initial starting period the voltage drop can be greater, as long as the permissible limits comply with the respective standards.

See the voltage drop table below on insulated PVC products operating at 70°C and room temperature at 30°C, installed as stated in the B1 reference method.