Kohler 23EKOZD

TP-6953 7/19 129Section 7 Troubleshooting
Step Potential Cause
Explanation Troubleshooting
Fault: Dead Bus Sensed When Live Bus Expected
1 The wiring was not
connected between the load side of the paralleling breaker for this generator and the paralleling bus
This generator controller observed accurate bus voltage when it closed the breaker, the other generator controller did the same, but the bus of this generator is not connected to the bus of the other generator. The other generator is energizing the load, this generator cannot energize the load as there is a disconnected wiring between this generator and the paralleling bus.
Verify wiring between the paralleling breaker and the paralleling bus of this generator.
2 The wiring was not
connected between the load side of the paralleling breaker for the other generator and the paralleling bus
This generator controller observed accurate bus voltage when it closed the breaker, the other generator controller did the same, but the bus of this generator is not connected to the bus of the other generator. The other generator is not energizing the load because it is not connected to it—this generator may be able to energize the load, but there is no simple way of telling this without connecting the output of the other generator.
Verify wiring between the paralleling breaker and the paralleling bus of the other generator.
Fault: Bus Voltage Out of Spec
1 The generators which
are connected to the paralleling bus are overloaded
When the generators which are supplying a load are overloaded, their engine speed will decrease, resulting in a decrease in output voltage. Sometimes this decrease in output voltage is sufficient to allow the generators to recover.
Verify the load requirements are met by a single generator. If not, it may be necessary to connect several low priority loads to load shed outputs from the paralleling generators to avoid overloading a single generator.
2 Excessive cable
lengths from generators to paralleling bus
Although a single generator can handle the load, the cables which connect the generator to the paralleling bus are too long or too small of gauge, resulting in insufficient bus voltage.
Increase wire size on the generator connection leads.
Fault: Bus Voltage Out of Spec
1 The generators which
are connected to the paralleling bus are overloaded
When the generators which are supplying a load are overloaded, their engine speed will decrease, resulting in a decrease in output voltage. Sometimes this decrease in output voltage is sufficient to allow the generators to recover.
Verify the load requirements are met by a single generator. If not, it may be necessary to connect several low priority loads to load shed outputs from the paralleling generators to avoid overloading a single generator.
2 Excessive cable
lengths from generators to paralleling bus
Although a single generator can handle the load, the cables which connect the generator to the paralleling bus are too long or too small of gauge, resulting in insufficient bus voltage.
Increase wire size on the generator connection leads.
Fault: Bus Frequency Out of Spec
1 The generators which
are connected to the paralleling bus are overloaded
When the generators which are supplying a load are overloaded, their engine speed will decrease, resulting in a decrease in output voltage. Sometimes this decrease in output voltage is sufficient to allow the generators to recover.
Verify the load requirements are met by a single generator. If not, it may be necessary to connect several low priority loads to load shed outputs from the paralleling generators to avoid overloading a single generator.
Fault: Failure to Synchronize
1 Varying load
requirements drive generator frequency unstable
Heavy variations in the load on a generator will cause the speed of the generator to vary significantly. It can be difficult to synchronize with a generator with continuously changing frequency.
Adjustment of synchronizing dwell time or synchronizing gains may improve ability to synchronize.
2 Fuel variations or other
environmental factors cause the generator frequency regulation to suffer
When the frequency regulation is impeded by atmospheric conditions or fuel quality, the ability to synchronize may be affected. Not only is the bus varying more than normal, but it is more difficult for the generator to control speed while synching.
It may be necessary to adjust the synchronizing gains.
3 Different sized units or
units of different fuel types
The factory synchronizing gains were calibrated for equal-sized units. The response of a large unit to a small one is slightly different than two small units. A diesel generator has significantly better frequency regulation than a natural gas generator .
It may be necessary to adjust the synchronizing gains.