Kohler EKOZD Series Service page 214

Close Attempt Fault
A Close Attempt Fault indicates that the breaker
attempted to close and that the breaker did not close
within the Fail to Close Delay. The controller will remove
the close signal after the Fail to Close Delay has expired,
so the breaker will probably not close.
A failure to close can be caused by external protective
relays inhibiting closure, wiring errors, incorrect voltage
for the motor operator, discharged charge spring in the
breaker, etc.
Fail to Close
A Fail to Close fault indicates that the controller has tried
to close the breaker for the Number of Close Attempts
without a successful closure. The failure to close fault
will start the Circuit Breaker Trip to Shutdown time delay,
which will cause the generator to stop after it times out.
Configuration Mismatch
The paralleling system will not permit any generator to
connect to the paralleling bus if the system voltage,
system frequency, and phase connection are different
on any of the connected generators. The generators
can't safely parallel with each other if these parameters
are different and the paralleling system does not know
which of the generators is correct and which is not.
Protective Relays
The controller will trip the circuit breaker and issue a
warning if any of the following conditions persist beyond
the associated time delay:
Over Voltage. This protective function is intended to
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protect the alternator from over excitation, but
primarily is used to protect the customer loads from a
potentially damaging condition.
Under Voltage. This protective function is intended
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to protect electric motors and sensitive electronics
from damage due to undervoltage. The low voltage
condition may also indicate a failure in the alternator
or in the sensing to the controller.
214 Section 12 Paralleling System Information
Over Frequency. This protective function is intended
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to protect any motors that are fed by the generator
from overspeeding and potentially damaging the
equipment that they drive.
Under Frequency. This protective function is
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intended to protect any motors or transformers that
are fed by the generator from potential overheating
and winding damage.
Over Power. This protective function can be used to
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protect the generator. The generator controller also
has an overpower shutdown, which is set to 102% for
standby applications and 112% for prime power
applications. A practical solution to the use of this
protective relay is to connect the load management
connections.
Reverse Power. This protective function is intended
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to protect the generator system from motoring
generators and to protect the fuel system of the
generator from operation in a dry state. This condition
is most commonly caused by a loss of fuel prime or
damage to a fuel line. A reverse power condition does
not otherwise damage the generator.
Over Current. This protective function can be used to
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protect the alternator of the generator from overload
conditions. The controller also contains internal
alternator protection that prevents thermal damage to
the alternator by stopping the engine.
Reverse VARs (Loss of Field). This protective
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function is required to avoid potential damage to the
generator caused by the alternator slipping a pole.
Pole slipping can occur when the generator is
providing real power (Watts) and is absorbing
reactive power (VARs). Slipping a pole can cause
damage to the engine crankshaft or the alternator and
typically causes voltage spikes on the generator
output—the condition should be avoided.
Note: The alternator can absorb VARs without damage
if the real power output of the generator is very
low, but the protective relay does not take the real
power into account, so it needs to be set to a low
enough threshold to protect against pole slipping.
The default of 20% protects the alternator in most
conditions, but the stability curve of the alternator
should be considered when adjusting the
parameters to a higher value than 20%.
TP-6953 7/19