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Why concealed? It’s a better alternative to overhead conductive charging structures that may be unsightly  and an obstacle in the passenger loading area, as well as being potentially  exposed to impact by tall vehicles, as well as exposure to birds nesting on and inside the structure and doing what birds do.

The 4C is encased in the ground and completely flush with the road surface. The heavy steel lid that opens only when charging occurs can be painted in the same color as the pavement, usually grey, to make it virtually undetectable.

The steel lid only is open when a bus is positioned above the steel box, so therefore it is never visible to bystanders. The steel lid is operated by air cylinders.

Why conductive? Conductive charging is much more efficient and powerful  (450 – 900 Kw) than the other kind of in-ground charging – inductive charging. That means super-fast charging without any of the worrisome magnetic emissions that are the side effect of inductive charging, especially at higher rates.

How does 4C work? The bus that requires charging is equipped with four charge plates underneath it, positive, negative, ground and ground confirmation.

The in-ground steel box contains corresponding charge plugs operated by air cylinders which rise to make contact with the charge plates under the bus. The powerful air cylinders push the charge plugs to provide a very solid contact which allows very fast and safe power transfer. The connection is established in only a few seconds and charging then commences. When charging is complete, the air cylinders retract the charge plugs, the steel lid closes and the bus is ready to depart.

The 4C is faster and less expensive to install than other charging technologies. A pavement saw-cut of 18” by 48” and excavation to a depth of 36” allows the insertion of the pre-made 4C steel box with air cylinders and charge plugs.

The 450 kW charger houses the air compressor that provides the compressed air to operate the air cylinders. The air hoses are run through the same conduit as the electric cables. The charger can be installed at a distance from the bus charging position and be concealed as well.  To avoid disturbing the pavement  by trenching, underground boring is recommended, a process that is commonly used when laying conduit under a street without disturbing traffic or cutting the pavement.


Powerful benefits: The 4C technology can transmit power more safely and at higher rates than other technologies in use today and eliminates overhead charging structures that may be considered eyesores, while being much faster and  less expensive to install than in-ground inductive charging systems.

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