Fig. 21. Controller.
Car Wiring for K-6 Controllers with two Motors
Fig. 22
Fig. 23. Motors in Series.
Fig. 24. Motors in Parallel.
With the aid of Figs. 22, 23 and 24, the wiring of a type K6 controller with two motors may be followed. Figs. [23] and [24] are for a different controller but can be used to assist in an understanding of the complicated diagram 22. The current leaves the choke or kicking coil of the lightning arrester and passes through the blow out coil of the controller. It then goes to the top finger T of the controller. On the first point the circuit is as shown in [Fig. 23]. The top segment A makes contact with the top or trolley finger. All but the lower five segments of the cylinder are electrically connected together by means of the iron cylinder upon which they are mounted. On the first point then the current passes from the cylinder over R1, and with straight series connections of the resistances, it goes through all of the rheostats under the car, and returns to the controller over the last resistance lead, R7. Behind the motor cut-out switches at the base of the controller this lead is tapped into a wire one end of which leads to finger 19 of the controller, and the other end through the cut-out switch and reverse cylinder to No. 1 armature. The current takes the latter path, passes through the armature of the motor and returns by way of the reverse cylinder, thence through the fields of No. 1 motor and then through the cut-out switch of No. 1 motor and to finger E1, of the controller. Segments O, M, N and L, shown in [Fig. 23], and corresponding segments of Figs. [22] and [24], are insulated from the remainder of the controller cylinder. From finger E1 and segment O ([Fig. 23]) the current passes over finger 15 through No. 2 cut-out switch and the reverse cylinder to the armature of No. 2 motor. Returning it passes through the reverse cylinder, then back through the fields of No. 2 motor and to the ground, which is usually through a connection on the motor casing.
On points 2, 3, 4 and 5, the successive series points of the controller R1, R2, etc., make contact with segments B, C, etc., Figs. [23] and [24], until finally finger 19 rests on segments J, the resistance is all cut out and the motors are connected in series directly across the line. A further movement of the controller handle changes the motors from series to multiple connection and inserts in the circuit a portion of the external resistance. There are four separate stages in making this change. First, the resistance fingers slide off their segments and the resistance is inserted in the line. Second, fingers E1 and G make contact with segments P and Q. Motor No. 1 is then across the line in series with the resistance; the circuit being from E1 to ground over G. When the lower finger E1 makes contact with P, the upper one has not yet left segment O. This short-circuits No. 2 motor, the path being from the ground, up wire G, thence by way of segments P and Q and through connecting clip V, between the two E1 fingers back through finger 15 to the motor.