How to choose charging pile cable specifications?

For a long time, charging anxiety has been the heart disease of electric vehicle owners, and installing a home charging pile has become the first choice to relieve anxiety. In addition to looking for an installation master, many car owners with strong hands-on ability choose to install it by themselves, but sometimes even though the installation process and wiring sequence are clear, they do not know how to choose the cable specifications, and even some inexperienced installation masters , are only half-understood.

How to choose the specification of charging pile cable? First of all, we need to understand that there are two types of cables for charging piles: BV type and RV type. Both RV and BV indicate wire and cable models.

Among them, BV wire includes BVV wire, BVVB wire and BVB wire. The core of this kind of wire is composed of a single-strand thick copper core. This type of wire is relatively hard, and we collectively call it "hard wire".

RV type wires include: RVV wire and RVVP wire. The core of this wire is composed of multiple strands of fine copper wire. This type of wire is relatively soft, and we generally refer to it as "soft wire".

The full name of RV type cable: copper core polyvinyl fluoride insulated flexible wire and cable, understood as flexible wire. RVVP cable: Shielded PVC insulated-PVC sheathed flexible wire. Among them, R represents the flexible wire, V represents the PVC insulation, V represents the PVC sheath, and P represents the shielding layer.

Most of the wires we use to install charging piles are BV-type wires. Under normal circumstances, household charging piles are 7KW AC charging piles. So what size wire should we choose?

According to the regulations of circuit science: pure copper wire of 1 square millimeter (cross-section) can withstand a current of 6.5A, while a single-phase (220v) electrical appliance 1KW is a current of 45A. According to this calculation, a wire of 10 square millimeters can withstand The number of kilowatts is 65A÷4.5A=14.4KW. By comparison, it means that a copper wire with a specification of 10 square millimeters can withstand two 7KW AC charging piles. Therefore, the household charging pile can choose a wire with a specification of 6 square millimeters.

Of course, if you are an installer, sometimes you need to install a higher-power DC charging pile. In order to facilitate you to better calculate the required cable specifications, I have listed the calculation formula for your reference:

The maximum carrying current of the 16 square line is 16*6.5=104A, and the maximum load is 104/4.5=23KW. It can install a double-gun 14KW and a single-gun 7KW AC charging pile;

The maximum carrying current of 25 square meters is 25*65=162.5A, and the maximum load is 1625/4.5=36KW. It can install 2 double-gun 28KW and 1 single-gun 7KW AC charging pile;

By analogy, a 35-square-meter cable can install 3 double-gun and 1 single-gun AC car charging piles. Note that wiring length is also something you need to consider. The distance between some car owners' household electric meters and the parking space is not generally far, and there are some ranging from tens of meters to hundreds of meters. Excessive wiring will cause resistance loss, which will affect the charging efficiency, and the cable will also heat up. Therefore, according to The wiring length selects the cable. The detailed loss calculation will be very complicated, here you just need to know: under normal circumstances, 7KW can use 6 square millimeters of cables according to the normal standard, but as long as the wiring distance exceeds 100 meters, the specifications of the cables should be thicker.

To learn more about charging pile cables, please visit OMG's official website: https://www.omgevcable.com/