Section 2 — Operation
Guardian
6.To crank and start the engine, set the Auto/Off/Manual switch to MANUAL.
7.Let the engine stabilize and warm up for a few minutes.
8.Set the generator’s main circuit breaker to its ON (or closed) position. The standby power source now powers the loads.
◆2.4.2 TRANSFER BACK TO UTILITY
POWER SOURCE
When utility power has been restored, you will want to transfer back to that source and shut down the generator. This can be accomplished as follows:
1.Set the generator’s main circuit breaker to its OFF (or open) position.
2.Let the engine run for a minute or two at
3.Set the generator’s Auto/Off/Manual switch to its OFF (or open) position. The engine should shut down.
4.Check that utility power supply to the transfer switch is turned OFF.
Do not attempt to activate the transfer switch manually until all power voltage supplies
to the switch have been positively turned off. Failure to turn off all power voltage supplies may result in extremely hazardous and possibly fatal electrical shock.
5.Use the manual transfer handle inside the trans- fer switch to move the main contacts back to their “Utility” position, i.e., loads connected to the util- ity power source (Figure 2.3, Page 19).
6.Turn ON the utility power supply to the transfer switch using the means provided.
7.Set the system to automatic operation as outlined in “Automatic Transfer Operation,” Section 2.2 (Page 18).
On sound attenuated models, there are LED read- outs on the control panel to notify you that one of these faults has occurred. There is also a “System Set” LED that is lit when all of the following condi- tions are true:
1.The Auto/Off/Manual switch is set to the AUTO position.
2.The “Not In Auto” dip switch is set to the OFF position on the control board.
3.No alarms are present.
◆2.5.1 LOW OIL PRESSURE SWITCH
This switch (Figure 2.4) has normally closed contacts that are held open by engine oil pressure during 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, and the Auto/Off/Manual switch must be turned to OFF and then back to AUTO.
◆2.5.2 HIGH TEMPERATURE SWITCH
This switch’s (Figure 2.4) contacts close if the tem- perature should exceed approximately 140º C (284º F), initiating an engine shutdown. Your generator will automatically restart and the LED will reset once the temperature has returned to a safe operating level.
Figure 2.4 – Low Oil Pressure and
High Temperature Switches
2.5PROTECTION SYSTEMS
Unlike an automobile engine, the generator may have to run for long periods of time with no operator pres- ent to monitor engine conditions. For that reason, the engine is equipped with the following systems that protect it against potentially damaging conditions:
1.Low Oil Pressure Sensor
2.High Temperature Sensor
3.Overcrank
4.Overspeed
◆2.5.3 OVERCRANK
This feature prevents the generator from damaging itself when it continually attempts to start and another prob- lem, 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 will light indi- cating 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.
20 Generac® Power Systems, Inc.
