[Illustration: Fig. 759.--Cutler-Hammer multiple switch starter with no voltage release; for use with large motors, or with motors of medium size where the starting conditions are severe or when more than fifteen seconds are required to accelerate the motor. In operation, the cutting out of each step of resistance is accomplished by a separate lever and the levers themselves are so interlocked as to prevent closing switches except in proper order, beginning with the lever on the left. The last switch (the one on right hand side) is held by an electro-magnet when closed, each of the other switches being held in the closed position by a latching device on the switch next to it. In front of each switch is placed a metal stop, so arranged as to prevent any switch being operated until the one next to it on the left has been closed. These metal stops constitute the interlocking mechanism and prevent the starting of the motor in any way except by closing the switches in regular rotation, thus insuring proper resistance in the circuit and protecting the motor from excessive starting currents. When the current is interrupted, the electro-magnet releases the last switch, which, on opening, releases the latch on the switch next to it, allowing that switch to open, and this in turn releases the next latch and so on, the switches opening automatically one after another. In starting the motor, each switch should be closed quickly and firmly, pausing a second or two before closing the next switch to give the motor time to accelerate.] [Illustration: Fig. 760.--Cutler-Hammer speed regulator with no voltage release, _regulation by armature resistance only_, reducing speed of motor _below normal_. No resistance in the armature circuit. No provision is made in regulators of this type for increasing the speed of the motor. The maximum speed obtainable when these regulators are used is, therefore, the normal speed at which the motor is designed to operate with no resistance in circuit. With all resistance in circuit and the motor taking normal current these regulators will reduce the speed of the motor 50 per cent. If the motor be taking less than normal current the percentage of speed reduction obtainable will be correspondingly less. The notched fan tail extension on the lower end of the lever engages with a magnetically operated pawl to hold the lever squarely on any contact so long as the no voltage release magnet is energized.] Ques. How is a wide range of speed regulation secured? Ans. By a combination of the two methods.