RV Generator Operating Tips    Cummins Southern Plains, Ltd.

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Pre-start Checks
Starting and Stopping Procedures
Resetting a Standard Generator
Resetting a Circuit Breaker
Cold/Hot Weather and High Altitude Operation
Generator Exercise, Storage and Returning to Service
Troubleshooting

Pre-start Checks
The following pre-start checks should be done at the first start of the day and every 8 hours of operation after that.
• Check oil level.
• Check exhaust system for leaks.
• Check fuel system for leaks and to make sure there is adequate supply.
• Check battery terminals for corrosion and battery for good condition.

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Starting and Stopping Procedures
When starting and stopping your generator, it is best to do so without loads.
• Turn off air conditioner and other large loads before attempting to start generator.
• If generator is diesel powered, preheat according to operator’s manual prior to start attempt. (Quiet Diesel units have automatic preheat cycle)
• Push and hold start switch. (Do not crank for more than 10 seconds and wait at least 30 seconds before trying again.)
• See “Troubleshooting” section of operator’s manual if set does not start.
• Before stopping, turn off air conditioner and other heavy loads, aloe ser to run for 2 minutes.
• Avoid running for long periods with no load loads under 1kW.

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Resetting a Standard Generator
• Disconnect or turn off as many applications as possible and try restarting the generator.
• Reconnect appliances one by one up to a total load that does not overload the generator.

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Resetting a Circuit Breaker
• If a breaker in the vehicle’s main power distribution panel or on the generator trips, there is either a short circuit or too many appliances being operated at the same time.
• Disconnect or turn off as many appliances as possible and reset the circuit breaker.
• If the breaker does not trip, reconnect the appliances, one by one, up to a total load that does not overload the generator or trip the breaker.

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Cold/Hot Weather and High Altitude Operation
• If you travel at high altitudes or in extreme temperatures, be aware that the generator can lose power in lower-density air caused by such conditions. You may not be able to operate as many electrical devices under these conditions as you could under normal operating conditions.
Altitude: Power output will decrease 3.5% for each 1000 feet above the Onan base rated altitude of 500 feet.
Temperature: Power output will decrease 1% for each 10ºF increase in ambient temperature above 85ºF.
• The generator is not the only appliance affected by hot weather – coach air conditioners require more power to run during high temperatures. For example, if the outside temperature increases from 85ºF to 100ºF, your air conditioner may require 20-25% more power to run efficiently. This can also limit your ability to run multiple electrical devices.
• Make sure the engine oil viscosity is appropriate for the weather temperatures. Onan recommends using 15W-40 oil. OnanMax oil is specifically formulated for the operating conditions of your generator.
• Set the altitude adjustment knob (if so equipped) for your altitude.
• make sure nothing blocks the air flow inlet and outlets from the generator.
• Keep the generator clean.
• Perform maintenance when due. Refer to the operator’s manual for maintenance schedules.
• Set the summer/winter preheat level (of so equipped) to winter in temperatures below 55ºF.

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Generator Exercise, Storage and Returning to Service
• It is important to run your generator to prevent moisture build-up, fuel system damage, and poor performance.
• If storing the coach for 2 months or more, we recommend using OnaFresh fuel stabilizer.
• Refer to operator’s manual for proper instructions.
• If use is infrequent, the generator should be exercised at least 2 hours every 4 weeks at approximately 1/2 load. Refer to chart in operator’s manual to calculate load. A single 2-hour exercise period is better than several short periods.

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Troubleshooting

Problem	Probable Causes	Checks/Solutions
Fails to crank	1. Low battery. 2. Bad battery connection. 3. Blown fuse.	1. Check battery fluid level. 2. Clean and tighten all battery cable connections. 3. Replace fuse on control panel.
Cranks slowly	1. Low battery. 2. Bad battery connection. 3. Incorrect oil viscosity. 4. Load connected.	1. Check battery fluid level. 2. Clean and tighten all battery cable connections. 3. Replace with recommended viscosity oil. 4. Disconnect load before starting.
Cranks but won’t start	1. Low fuel. 2. Fuel supply shutoff valve closed. 3. Carbon deposits on spark plug(s). 4. Low oil level.	1. Add fuel. 2. Fully open fuel supply valve. 3. Remove spark plug(s) and replace. 4. Add oil.
Exhausting black smoke	1. Dirty air filter. 2. Choke stuck or misadjusted.	1. Replace air filter. 2. Contact an Onan Certified RV Service and Parts Dealer.
Unit runs then steps, or stops when driving around a corner	1. Low fuel. 2. Low oil level. 3. Excess oil.	1. Add fuel. 2. Add oil. 3. Reduce engine oil level
Unit starts and runs, then stops when the start switch is released	1. Low fluid levels. 2. Possible overheating. 3. Other functional problem. 4. No AC output.	1. Check and bring all fluid levels up to the appropriate levels. 2. Check for blocked air flow or other possible causes of overheating. 3. Contact an Onan Certified RV Service and Parts Dealer. 4. Contact an Onan Certified RV Service and Parts Dealer.
Unit runs then surges	1. Loose or worn spark plug leads. 2. Defective ignition coil, wiring, or control components. 3. Faulty spark plug(s). 4. Governor out of adjustment. 5. Combustion air preheat malfunction. 6. Carburetor icing. 7. Carburetor varnishing.	1. Check spark plug leads at spark plug and ignition coil. 2. Contact an Onan Certified RV Service and Parts Dealer. 3. Remove spark plug(s) and clean or replace. 4. Contact an Onan Certified RV Service and Parts Dealer. 5. Contact an Onan Certified RV Service and Parts Dealer. 6. Move carburetor pre-heater to the winter position. 7. Try fuel system cleaner and contact dealer if no change.
Circuit breaker trips	1. Overloaded circuit.	1. Turn off some of the electrical load, and reset the circuit breaker.

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