The input power to the screw jacks should not exceed the power rating shown in the specifications table. Maximum input speed in rpm (revolutions per minute) to a screw jacks worm shaft should not exceed 1800 rpm for E-Series and M-Series screw jacks, however the high performance S-Series screw jacks can operate at up to 3000 rpm. Power Jacks cannot accept responsibility for the overheating and rapid wear that may occur should these limits be exceeded. Power increases in direct proportion to the speed, and the motor size will be out of proportion to the screw jack model design rating should the speed become excessively high. When selecting the maximum permissible speed for a screw jack arrangement, always check to see that the power rating of the screw jack model is not exceeded.