Company: Invacare Corp.
Product: Power wheelchairs and scooters
Date: 8/26/03
With regard to the 80 amp fuse and …wire assembly, the May 15, 2003 and May 20, 2003 responses indicate that an 80 amp current through this assembly is only sustained for a short period of time. Invacare states that a continuous 80 amp current would not be sustained because the controller software is designed to prevent this condition by limiting the current. Invacare states that if the controller software failed, the controller would shut down with such a continuous load; however, Invacare has not provided adequate validation that the controller would function in this manner. The reports by …and …state that the highest temporary current from the battery is 130 amps when the motors are in a stalled condition. This current is only drawn for about 7 seconds after which the controller limits the current to 75 amps. … suggested that tests be performed to confirm that the 80 amp fuse would trip before the thermal limit of the …wire is reached, if the controller failed to limit the 130 amp current within the 7 seconds time limit. Invacare has not provided adequate validation that the 80 amp fuse would trip before the thermal limit of the…wire is reached if the controller failed to limit the 130 amp current within the 7 second time limit per…recommendation.
FDA District: Cincinnati District Office
