A lot of people inquire about a J1772 Extension Cord. It seems that either the length of the cord for their EVSE is too short for them to use, or they park their EV outside, etc. So in 2012, I came up with the J1772 Extension Cord.
TucsonEV has been selling J1772 Plugs and Inlets since December 2010. We introduced the J1772 Adapter Box in 2011, permitting people who had done conversions to charge with J1772 EVSE’s. We consulted with Dostar to finalize the Proximity circuit that is presently in their J1772 Plug. We sold our first J1772 Extension cord in January of 2012 using 30A UL listed EVE cord and have been selling them ever since.
Some people have complained that since the proximity wire is not in the cord there will be a ‘hot’ disconnect. Nothing could be further from the truth. There cannot be a ‘hot’ disconnect if the J1772 Standards are adheared to in the EVSE and the vehicle.
The J1772 Specification does not call for the proximity wire/signal to be in the cable that goes from the Plug to the EVSE, it only requires the Pilot signal wire. The proximity signal has nothing to do with the EVSE, therefore there is no reason for it to be in the cord. The proximity signal is connected only to the charger onboard the vehicle. Once the latch is pushed the value of the signal changes and tells the charger to immeadiately stop charging.
One of the design requirements of the J1772 Spec is that the Pilot pin is shorter than any other pin so that when the Plug is inserted into the Inlet, it is the last connection to be made. That means that when the Plug is unplugged it is the first to be disconnected. In the world of electricity this is known ‘last in, first out’