Kohler 22.5RZ Generator Set

⚠ High voltage is present at regulator board P1 connector and terminal strip when set is running.

⚠ Do not exceed 285 Volts when adjusting Pot. 2; regulator board damage may result.

Tools: AC voltmeter, 0-300 V AC, ±0.5%, Frequency counter, 45-75 Hz, ±1%, Potentiometer adjustment tool or small blade screwdriver, Load bank (for boards with Pot. 4 — Load Shed)

1. Disconnect generator from load; place main switch OFF and lift enclosure cover.
2. Check wire jumpers on regulator board and arrange per Table 3-1/3-2 (J1, J2, J3).
3. For single-phase connection, lift lead V9 from controller board terminal strip and insulate.
4. Adjust external voltage adjustment potentiometer to approximate midpoint of range.
5. Connect AC voltmeter and frequency counter between leads V7 and V8.
6. Break adjustment seals on Pots. 1, 2 and 3.
7. Turn Pot. 1 full clockwise and Pot. 2 full counterclockwise.
8. Start generator set with no load.
9. Adjust Pot. 2 (Volt Adj.) for the specified output voltage.
10. Observe LED; if flickering, alternately adjust Pot. 3 and Pot. 1 until steady glow.
11. Perform overvoltage shutdown check and adjustment (Pot. 6) per 50/60 Hz limits.
12. Perform overspeed shutdown check and adjustment (Pot. 5) per 50/60 Hz limits.
13. On NFPA models, check voltage adjustment range (at least ±10 Volts).
14. Seal Pots. 1, 2 and 3 with insulating varnish.

⚠ DANGER OF ELECTROCUTION! High voltage present when set is running.

Tools: AC voltmeter 0-300 V, Frequency counter 45-75 Hz, Potentiometer adjustment tool

1. Disconnect generator from load. Place main switch OFF.
2. Check wire jumpers on regulator board per Table 3-1.
3. For single-phase, lift lead V9 and insulate.
4. Connect AC voltmeter and frequency counter between V7 and V8.
5. Start generator with no load.
6. Adjust Pot. 2 for specified output voltage.
7. Observe LED; adjust Pot. 3 and Pot. 1 for steady glow.
8. Seal pots with insulating varnish.

Tools: Ohmmeter

1. Disconnect V7, V8 and V9 from terminal strip and insulate.
2. Disconnect load leads and insulate (separately excite under no load).
3. Disconnect brush leads F1 and F2 at quick disconnect.
4. Check brush assembly for weak springs, loose holder, sticking brushes or improper alignment.
5. Check continuity between quick disconnect point on each brush lead and its adjacent slip ring; repair or replace if faulty.

⚠ See Safety Precautions before making any battery connections.

Tools: Fast Check and harness (A-291930 and 269955), Variable low voltage DC power supply, 0-50 Volt, 3 amp minimum, Stopwatch

1. Unplug harness connector inside meter box.
2. Connect Fast Check Harness to harness connector inside meter box (connectors are keyed).
3. Push wiring harness connector onto plug at top of Fast Check.
4. Move Generator Main Switch on controller to OFF.
5. Move Fast Check engine switch to OFF.
6. Clip red (+) and black (-) harness leads to 12-Volt battery or DC power supply.

⚠ HIGH VOLTAGE! Potential danger of electrocution.

Tools: 208-240 Volt AC power source, On-Off switch, SCR module (pre-tested), 120 or 240 Volt AC light bulb and socket, Jumper wires

1. Connect regulator board to good SCR module.
2. Wire 120/240-Volt AC light bulb across (+) and (-) of SCR module.
3. Wire on-off switch in series with AC power source.
4. Wire 208-240 Volts to V7 and V8.
5. Close switch to apply power; lamp should light.
6. Adjust Pot. 2 clockwise for max intensity, counterclockwise to extinguish.

⚠ The SCR module may be damaged if the negative (-) lead of the battery is not connected to the POSITIVE (+) pin.

Tools: Ohmmeter (RX1 scale), 12-volt DC source, 100-500-ohm resistor, 12-volt lamp, Momentary jumper

1. Connect ohmmeter from (+) to (-): high resistance one direction, low the other.
2. Connect ohmmeter from AC1 to (+): high resistance both directions; repeat for AC2.
3. Connect ohmmeter from AC1 to (-): high in one direction, low in the other; repeat for AC2.
4. G1 to (+) should read low one direction, higher the other; repeat for G2.
5. Replace SCR module if any check is faulty.
6. Connect negative (-) lead from DC source to positive (+) pin on SCR module.
7. Connect positive (+) lead from DC source, with lamp in series, to AC1 pin; lamp should not glow.
8. Momentarily connect jumper with resistor in series from positive of DC source to G1 pin; lamp should glow and continue glowing.
9. Repeat with lamp connected to AC2 pin and jumper to G2 pin.

Tools: Voltmeter, Ammeter

1. Disconnect and insulate V7, V8, V9, VO and V4 from terminal strip; disconnect and insulate L1, L2 and L3.
2. Disconnect exciter leads F1 and F2 at quick disconnect.
3. Place voltmeter across F3 and F4; connect ammeter in series with F3.
4. Start unit and read battery voltage; ammeter should read 4/10 of 1 amp.
5. If voltage is not present, problem is in controller; if current is high or low, problem is in the exciter field.
6. Check L1, L2, L3, V7, V8, V9, VO and V4 with a voltmeter for output (25-35 volts).
7. If there is output, check the Automatic Voltage Regulation (AVR) circuit.

⚠ HIGH OUTPUT VOLTAGE DURING TESTS MAY ENDANGER HUMAN LIFE OR DAMAGE EQUIPMENT!

Tools: 12-volt battery, DC ammeter

1. Disconnect and insulate L1, L2, L3, V7, V8, V9, VO and V4.
2. Connect brush leads in series with 12-volt battery and DC ammeter.
3. Record ammeter reading.
4. Start unit and observe ammeter.
5. Ammeter reading should remain same.
6. Check L1, L2, L3, V7, V8, V9, VO, V4 for AC output.

⚠ EXPLOSIVE GASES! Locate auxiliary battery at least 18 inches above floor.

Tools: Voltmeter, Ammeter

1. Disconnect and insulate V7, V8, V9, VO and V4.
2. Disconnect and insulate L1, L2, L3.
3. Disconnect exciter leads F1 and F2.
4. Place voltmeter across F3 and F4.
5. Connect ammeter in series with F3.
6. Start unit and read battery voltage.
7. Check L1, L2, L3, V7, V8, V9, VO, V4 for 25-35 volts output.

⚠ High output voltage during tests may endanger human life or damage equipment; disconnect generator from load when troubleshooting.

⚠ Auxiliary battery should be located at least 18 inches above the floor in enclosed areas.

Tools: 12-volt battery, DC ammeter, Voltmeter

1. Connect for separate field excitation as shown; disconnect and insulate L1, L2, L3, V7, V8, V9, VO and V4.
2. Connect brush leads in series with a 12-volt battery and DC ammeter.
3. Record ammeter reading.
4. Start unit and observe ammeter; reading should remain the same.
5. If current increases considerably, a running short in the rotor is indicated; if current drops to zero, an open rotor is indicated.
6. If shorted or open rotor, replace.
7. While running, check L1, L2, L3, V7, V8, V9, VO and V4 for AC output.

Tools: DC voltmeter, 12-Volt DC power supply

1. Connect speed sensor, voltmeter and DC voltage source as shown.
2. Touch sensing surface with a flat piece of iron or steel at least 1/4 cubic inch (4.1 cm3).
3. Test voltmeter reading should equal voltage source volts.
4. Remove iron or steel from sensing surface and observe no test voltmeter reading.

⚠ High voltage present at regulator board P1 connector and terminal strip when set is running.

⚠ 240 Volts will shorten life of 120-Volt bulb.

Tools: 208-240 Volt AC power source, On-Off switch, Pre-tested SCR module, 120 or 240 Volt AC light bulb and socket, Jumper wires

1. Connect regulator board to a good SCR module as shown.
2. Wire a 120 or 240-volt AC light bulb across (+) and (-) of SCR module.
3. Wire on-off switch (open position) in series with AC power source.
4. Wire 208-240 volts to V7 and V8 on terminal strip in regulator/terminal strip tray.
5. Close switch to apply power; lamp should light.
6. Adjust Pot. 2 to clockwise limit; adjust to counterclockwise limit to extinguish bulb.
7. Connect battery (+) to P terminal and battery (-) to common wire between hourmeter and reset lamp.
8. Turn on AC and DC power; adjust overspeed Pot. 5 counterclockwise until reset lamp turns on; return 1/8 turn clockwise.
9. Reset fault; turn overvoltage Pot. 6 counterclockwise until reset lamp comes on; return 1/8 turn clockwise.
10. If test indicates a faulty regulator board, replace and refer to new board adjustment procedure.