Electrical Distribution Equipment
In order to connect and power the charger system, standard electrical gear and equipment is required. This gear and equipment is essentially the same equipment used in distributing power in buildings. This equipment includes transformers, disconnect switches, panelboards, switchboards, and sometimes generators and ATS’s. This equipment is sized, arranged, and connected based on the size of the charging system.
When selecting EV distribution equipment, it is important to consider the environment the chargers are being installed in, and select an appropriate NEMA rating. A NEMA (National Electrical Manufacturers Association) rating refers to a standard set by the NEMA to define the types of environments in which an electrical enclosure can be safely used. These ratings are primarily used in North America and are designed to classify the level of protection provided by electrical enclosures against environmental factors such as moisture, dust, and other contaminants.
NEMA ratings are typically expressed as a combination of letters and numbers. The format is NEMA Type XY, where "X" represents the degree of protection against solids (dust) and "Y" represents the degree of protection against liquids (moisture).
Here are a few examples:
NEMA 1:
Solids (X): Protection against solid objects (non-hazardous), such as dust.
Liquids (Y): Provides a basic level of protection against dripping water.
NEMA 3:
Solids (X): Protection against solid objects.
Liquids (Y): Protection against spraying water.
NEMA 4X:
Solids (X): Protection against solid objects.
Liquids (Y): Protection against splashing water and corrosion.
These are just a few examples, and there are several other NEMA ratings that cater to specific environmental conditions. It's important to consult the NEMA standard or the specific documentation for a piece of equipment to understand the level of protection it provides and ensure it is suitable for the intended application and environment.
Asides damage from natural causes, you cannot overlook the potential for human-caused damage on our infrastructure from vandalization, etc. Not only keeping maliciousness out of these critical areas, but also protecting curious persons out of hazardous areas. For this reason, proper protection and resiliency should be provided to electrical equipment supporting this type of infrastructure. At the minimum, fence structures should be erected around the area containing distribution equipment.
