A field service person recently found that 24 volts and 120 volts don't mix. The hard way. Field service people should take great care to realize this when servicing/replacing Pentair Fleck valve drive motors commonly found on models 2750,2850,2900,3150, 3900.
Here is the golden rule: If the timer controls are Electronic (NT, NXT, XTR, SXT) the drive motors will be 24 volt. If the timer controls are analog (3200) the drive motors are 120 volt. The 24 volt motors are DC current and cylindrical in shape with a small capacitor at the end. The 120v motors are more square with a wound coil at the motor.