One leg of the power supply (white wire) is connected to Terminal 1 of the overload. Terminal 3 of the overload is connected to the common terminal on the hermetic. The other leg of the power supply (black wire) is connected to a relay terminal that splits to connect to the relay’s switch on one side and the relay’s coil on the other. The relay coil connection leads to the compressor’s run terminal. The relay switch connection leads to the start capacitor and then to the start winding terminal on the compressor. These connections place the overload in series with the common terminal (and both windings). The run and start windings are connected in parallel. The switch and start capacitor are in series with the start winding. the start winding. Capacitor size varies according to the horsepower rating of the motor and the load placed upon it. Be sure to use an exact replacement for a start capacitor. Open-Type CSIR Electrical connections for the CSIR motor are similar to electrical connections for the split-phase motor. The only difference is the addition of a start capacitor. See Figure 25‑29. On this type of motor, the start capacitor, centrifugal switch, and start winding are connected in series. The order in which the components are connected makes no difference however, the components must be in series so the switch can disconnect them from the circuit. Reversing Rotation. On the open-type CSIR motor, rotation is reversed by swapping the two wires that control current flow to the start winding. Information for identifying these wires is located on the motor’s data plate or inside the cover plate. Hermetic CSIR Motor The hermetic CSIR motor is used when the compressor is required to start under high head pressure and high load conditions, such as in systems using automatic and thermostatic expan- sion valves. Hermetic Electrical Connections. The CSIR hermetic compressor looks like other hermetic compressors, except the start capacitor is mounted immediately above (or beside) the electrical terminal box to simplify wiring connections. See Figure 25‑30. Start Run Start Run Start capacitor A B Goodheart-Willcox Publisher Figure 25‑29. The order of components in the start circuit does not matter as long as they are wired in series. A—The start capacitor is between the centrifugal switch and the start winding. B—The start winding is between the switch and the capacitor. N L1 Black wire White wire Overload Current relay Start capacitor Switch Relay coil C S R Capacitor-Start, Induction-Run (CSIR) Motor 1 3 Goodheart-Willcox Publisher Figure 25‑30. Electrical connections for a CSIR motor in a hermetic compressor. The start winding, start capacitor, and relay switch are in series. Chapter 25 Motors 501 Copyright Goodheart-Willcox Co., Inc.