SUBJECT: Gasoline-Electric Hybrid Vehicles
TOPIC: 110-volt AC Cables
OBJECTIVE: Determine whether any colored cables exist inside the passenger compartment of a gasoline-electric hybrid vehicle that carry 110-volt AC current.
TASK: The rescue team shall tour and inspect a new or late-model gasoline-electric hybrid vehicle and by working with representatives of the manufacturer or dealership, determine if colored AC power cables exist within the passenger compartment.
As a vehicle rescue instructor who presents training on a variety of vehicle-related rescue topics, it is evident that there remains great interest among responders for training in procedures to implement when encountering a gasoline-electric hybrid vehicle at a crash or vehicle fire. A principal component of hybrid training revolves around the high-voltage cables present on these vehicles. With DC voltages ranging from 36 volts up to 500 volts, it is understandable that responders are curious about and concerned with this common feature of a hybrid.
One of the statements this author has always made during hybrid training presentations is that all high-voltage cables run outside of the actual occupant or passenger area. Connecting the high-voltage battery in the rear area to the electric drive motor unit at the front of the vehicle, these large cables are typically routed beneath the floorpan of the vehicle, usually inside a metal sleeve or conduit. These cables carry DC current.
It turns out that with the introduction of recent gasoline-electric hybrids from several manufacturers, this statement about power cables not being inside the passenger compartment is no longer exactly true. In fact, on a few new hybrids, large power cables do enter the passenger compartment and are located very close to the front or rear seat occupants. On these new-model hybrids, these cables carry 110-volt AC household-type current.
With the design of the twin SUV hybrids produced by Ford Motor Co. — the Ford Escape Hybrid and the Mercury Mariner Hybrid — orange cables enter the passenger compartment to provide the 110-volt AC current to a single three-prong electrical outlet located on the vehicle's center console. This power outlet allows an electrically powered device that would normally operate on household current to be plugged into this outlet and operate normally. The orange cables carry AC current of 110 volts at up to 150 watts of current.
The first models of General Motors' twin hybrid pickup trucks — the GMC Sierra and Chevy Silverado — have a similar 110-volt AC outlet mounted inside the passenger compartment. Again, AC power exists inside the cable supplying this receptacle unless the vehicle has been properly powered down by responders on scene.
The new twin full-size SUV hybrids from GM — the GMC Yukon Hybrid and the Chevy Tahoe Hybrid — also have a single three-prong AC electrical outlet. This time, however, it is mounted along the driver's-side rear trim panel inside the passenger compartment at the third-row seat position. Again, AC current flows to this outlet as long as the vehicle is energized.
The teaching point here is for both responders and vehicle rescue instructors. Start spreading the word about the presence of AC power cables and 110-volt household receptacles located inside the passenger compartment of selected models of gasoline-electric hybrids.
It seems that we all are becoming increasingly aware of a hybrid vehicle's high-voltage DC cables that run from the high-voltage battery underneath the vehicle to the front engine compartment. Now, with these newest hybrids, we must not forget about the AC voltage cables that deliver AC current to a receptacle physically inside the passenger compartment, right where our patients may be located. Responders, power down the hybrid vehicle. That action greatly reduces our electrical system risks. Be smart. Be careful!
TASK: The rescue team shall tour and inspect a new or late-model gasoline-electric hybrid vehicle and by working with representatives of dealership, determine if and where colored 110-volt AC power cables exist within the passenger compartment.
RON MOORE, a Firehouse® contributing editor, is training chief for the McKinney, TX, Fire Department. He also authors a monthly online article in the Firehouse.com "MembersZone" and serves as the Forum Moderator for the extrication section of the Firehouse.com website. Moore can be contacted directly at Rmoore@firehouse.com.