Section 3 — Operation

Air-cooled Generators

Low speed exercise will be handled as follows:

1.The standard start sequence will be initiated.

2.The unit will run at 2,400 RPM.

3.If utility is lost during exercise, the controller will do the following:

Wait 10 seconds for utility to return.

If utility returns within 10 seconds, continue to exercise at 2,400 RPM.

If utility is still lost after 10 seconds, run the engine up to 3600 RPM and transfer the load. At this time the controller will exit the exercise routine and assume full automatic operation.

3.6PROTECTION SYSTEMS

‹3.6.1 LOW OIL PRESSURE SWITCH

This switch (Figure 3.3) has normally closed con- tacts that are held open by engine oil pressure dur- ing cranking and operating. Should oil pressure drop below the 8 psi range, switch contacts close, and the engine shuts down. The unit should not be restarted until oil is added. The AUTO/OFF/MANUAL switch must then be turned to OFF and then back to AUTO.

‹3.6.2 HIGH TEMPERATURE SWITCH

This switch’s contacts (Figure 3.3) close if the tem- perature should exceed approximately 140º C (284º F), initiating an engine shutdown. The generator will automatically restart and the LED on the generator control panel will reset once the temperature has returned to a safe operating level.

‹3.6.3 OVERCRANK

This feature prevents the generator from damaging itself when it continually attempts to start and anoth- er problem, such as no fuel supply, prevents it from starting. The unit will crank and rest for a preset time limit. Then, it will stop cranking, and the LED on the generator control panel will light indicating an overcrank failure. The AUTO/OFF/MANUAL switch will need to be set to OFF and then back to AUTO to reset the generator control board.

NOTE:

If the fault is not repaired, the overcrank feature will continue to activate.

3.7.3.1 Approximate Crank Cycle Times

7kW Units:

15 seconds ON

7 seconds OFF

7 seconds ON

7 seconds OFF

7 seconds ON

7 seconds OFF

7 seconds ON

7 seconds OFF

7 seconds ON

7 seconds OFF

7 seconds ON

If the unit fails to start, the overcrank alarm LED will be illuminated.

10kW, 13kW and 16kW Units:

• 16 seconds ON

Figure 3.3 – Low Oil Pressure and

• 7 seconds OFF

High Temperature Switches

• 16 seconds ON

 

 

• 7 seconds OFF

Low Oil Switch

High Temp Switch

• 7 seconds ON

• 7 seconds OFF

 

 

 

 

• 7 seconds ON

 

 

• 7 seconds OFF

 

 

• 7 seconds ON

 

 

• 7 seconds OFF

 

 

If the unit fails to start, the overcrank alarm LED will

 

 

be illuminated.

Loosen

Oil Filter

Oil

Drain

Hose

‹3.6.4 OVERSPEED

This feature protects the generator from damage by shutting it down if it happens to run faster than the preset limit. This protection also prevents the gen- erator from supplying an output that could poten- tially damage appliances connected to the generator circuit. Contact the nearest Authorized Dealer if this failure occurs.

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Generac Power Systems 5252, 5254, 5251 ‹ 3.6.1 LOW OIL Pressure Switch, ‹ 3.6.2 High Temperature Switch, ‹ 3.6.3 Overcrank