Recharging an electric vehicle can mean leaving the car unsupervised and plugged into a recharging unit for hours at a time. This leaves the cable vulnerable to a long list of potential risks, including forgetful owners driving off while still plugged in, and people tripping over the cable. If the cable breaks, it could expose people and property to dangerous levels of high-voltage electricity. To head-off those risks, engineers at Integro, New Britain, Conn., have developed the Tutor recharging cable for Level II charging stations (240 V and 30 A).
The key to the Tutor is its waterproof breakaway connector. Several of its features are aimed at making the entire cable safer. For example, nickel-plated pins on the male side have different sizes. Those carrying electricity are longer than the one handling data signals that control the recharging cycle. So if there is a force -- whether from a pedestrian, another car, or the user -- tugging at the cable, the first connection broken is the signal channel. A break in the signal channel instantly shuts down the charging process and stops current being sent to the car, so there is no chance of arcing or stray voltages. It also prevents any current from passing through the cable until the short signal pin is re-engaged.
The male and female connectors are shaped so one plug fits inside the other but cannot be completely removed from it, even when the pins are totally disengaged. So both connectors remain attached even if electrical connections break. This lets operators of recharging units simply reseat the connectors in case of accidents, avoiding downtime. It also prevents theft and limits vandalism.
The cable operates in temperatures from -30 to 120°F. It takes 50 lb of force to disconnect the pins in the breakaway connector, and at least 300 lb to tear the breakaway connector apart.