The Relay is a generator-set controller. It is used on generator sets from Kohler, including the 5kW Low Profile RV, CS12 and Fast-Response II.
| Symptom | Cause | Remedy |
|---|---|---|
| Battery voltage must show at connector Pl-12 socket in order for controller to function | Check voltage from Pl-12 socket to ground (Figure 3-8). | |
| Blown Fuse | Defective gauges, Connector P2, socket 1 to ground; Overvoltage, Connector P2, socket 2 to ground; Crank, Connector Pl, socket 1 to ground; Safeguard Breaker, Connector Pl, socket 3 to ground; Generator Field Flash, Connector Pl, socket 4 to ground; Engine Run, Connector Pl, socket 7 to ground | |
| Engine will not crank with Master Switch in RUN position (no power to controller circuit board) | Battery weak or dead, Reversed or loose battery connections, Faulty Pl connector or DC wire harness | Recharge or replace battery. Verify proper operation of battery charger. Check for proper battery connection (negative - ground). Clean and tighten battery connections. |
| Fluctuating Voltage | 1. Check the generator output leads for proper connections (refer to Section 7, Wiring Diagrams). 2. Check for loose connections to the voltage regulator, LED board, photo transistor board or FR Activator. 3. Check the stator for shorted or open windings, refer to Component Testing. | |
| Generator set will not start or stops running due to a fault shutdown (fault lamp lit) | Engine Coolant Temperature above 225°F (107°C). Cooling System Malfunction. Engine oil pressure between 5.5-10.5 psi (38-72 kPa) on diesel-powered models; 11.5-18.5 psi (79-126 kPa) on gasoline-powered models. Governed frequency in excess of 70 Hz (all models). More than 45 seconds of continuous cranking. More than 75 seconds of cyclic cranking. Locked rotor. Overcrank Lamp Flashes: Speed sensor signal absent longer than one second. | Consult the Engine Service Manual for detailed information on correcting engine related faults. To reset the set after a fault shutdown, see Section 2. Dee-3 Controller - “Resetting.” |
| High Engine Coolant Temperature | Excessive coolant (Q) | Check coolant level. Check ignition timing. Check for cooling restrictions and radiator cooling air. |
| Ignition System | Check for battery voltage at ignition coil, Check ignition points. Check engine ignition system. | |
| K4 (emergency stop) relay: defective | Engine electrics, overvoltage board, circuit board | Isolate the defective component and repair or replace. |
| No AC output available | Check for 120 volts AC | |
| No Output On Any Phase | 1. Check the safeguard breaker (if equipped). If open, close, and with set running check AC voltmeter for proper output voltage. 2. If proper output does not show: a. Check the 15-amp fuse on controller. b. Check wire 1B from safeguard breaker and wire 7N (ground) to voltage regulator. c. Check wire 70 between CR relay and Safeguard breaker (if equipped) through DC engine 'harness connector (P1, J1) pin 20. 3. If all items in step 2 are okay, proceed to the LED circuit board flashlight test and AVR (voltage regulator) test as described in Component Testing. 4. Tests indicate LED and AVR are functioning properly, proceed to the Photo Transistor Board test as described in Component Testing. 5. If the Photo Transistor Board test indicates it is functioning properly, proceed to the Exciter Armature test as described in Component Testing. 6. If the Exciter Armature test indicates the armature is functioning properly, proceed to the Generator Field test as described in Component Testing. 7. If the Generator Field test indicates the field is functioning properly, replace the FR Activator as described in Component Testing. | |
| No fuel | Check for fuel at pump or carburetor. Check for clogged fuel filter. Check engine fuel system. Ignition system. Check for battery voltage at ignition coil. Check ignition points. Check engine ignition system. | |
| No voltage at SS solenoid coil | Open CR, 1CR or CC (I) contacts in series with SS solenoid. Open in P5 connector (pin 4) Open in P1 connector (K) (pin 16). | |
| Over-Voltage | 1. If over-voltage occurs, disconnect harness plug at voltage regulator. If over-voltage continues, problem lies in photo transistor circuit, and/or FR-Activator. If output voltage disappears, problem lies in voltage regulator, connections or wiring. See “Component Testing.” 2. If over-voltage is read with the Safeguard breaker open or closed check the photo transistor board for a grounded 'C' lead. Check the photo transistor board as described in “Component Testing.” 3. If the Photo Transistor Board is functioning properly, check for reversed E and C leads on the FR Activator. 4. If Photo Transistor Board functions properly and is properly connected, but ceiling voltage is read, replace FR Activator. See “Component Testing ~ FR Activator.” 5. If over-voltage is read with the Safeguard breaker closed only, check for an open circuit in leads V7 and V8 to the voltage regulator. If these circuits are open or shorted, repair or replace. Check the voltage rheostat circuit (leads 67 and 68). Repair and replace as necessary. 6. If all the circuits in step 4 are okay, check the voltage regulator (AVR) as described in “Component Testing.” | |
| Overspeed | Governed frequency exceeding 70 Hz will energize SDR relay and shutdown unit. Overspeed shutdown may be caused by governor malfunction/misadjustment or rapid loss of load. | |
| Unit Cranks but No fuel | Check for fuel at pump carburetor. Check for clogged fuel filter. Check engine fuel system. | |
| Unit Runs For 30-60 Seconds then Shuts-Down. | If 1CR relay does not energize, normally closed contacts of relay will energize 1TS thermal switch and shut down unit. Check for battery voltage at controller terminal strip VO and V7. See Generator troubleshooting (No Output). | |
| Unit Runs For @No or Low Engine Oil Pressure (P) | Engine oil pressure (P) | Correct engine oil pressure problem. |
| Unit Will Not Crank | Reversed or Poor Controller Switch battery connections negative ground In TEST connection. Battery Position) Cable connections must be clean and tight. | |
| Unit runs for 30-60 seconds then shuts down | No AC output available to 1 CR relay coil. Safeguard breaker (if equipped) must be closed. | Check for 120 volts AC to controller terminal strip VO and V8. See generator troubleshooting (No Output). If 1CR relay does not energize, normally closed contact of relay will energize ITS thermal switch and shut down unit. |
| Will Not Crank | Low battery Voltage at battery (A) (CR relay Battery cabies terminals must be at least 10 volts, recharge if necessary. | Clean and tighten battery cable connections. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.