MA 3. The MA 3 unit is electrically and mechanically the same as the MA 2 unit with two exceptions: the speed of the motor, and the time-interval provided by the thermal delay switch T. The excat figures on relative speed of the motor in MA 2 and MA 3 are not known. The difference between MA 2 and MA 3 with respect to the thermal delay switch have to do with the time required for its contact f1 to break its normal contact and make its "hot" contact.