Kohler EKOZD Series Service page 206

12.3.1 Low Wye
The Decision-Makerr
paralleling in a low wye configuration. This connection is
the simplest and the least likely to cause confusion. In
low wye configuration, the sensing leads (L1, L2, L3) are
connected to the same points as the previous sensing
leads (V7, V8, V9) from legacy product. The output
leads from the alternator pass through the CTs only
once, which is also identical to legacy product.
12.3.2 High Wye
The Decision-Makerr 3500 controller is a direct sensing
controller—high wye voltage is measured at L1, L2, L3
and Neutral. Legacy product measured ~ of the output
voltage using the V7, V8 and V9 taps but the taps are not
used for the Decision-Makerr 3500 controller (which
may cause confusion for those that are accustomed to
using the center taps for voltage metering). The
generator current that the Decision-Makerr 3500
controller measures is intended to be the actual
generator current (each phase makes a single wrap
through the CT) where legacy product wrapped the
output leads through the CTs twice in the high-wye
configuration. The bus sensing is also intended to be
connected directly to L1, L2, and L3 of the paralleling
bus (opposite side of the motor-operated paralleling
breaker), where legacy product typically used a
transformer or contactor.
12.3.3 Delta
The Decision-Makerr
paralleling in a delta configuration, but it is important to
note that the neutral of each generator needs to be
bonded to the same phase (or a point between the same
two phases). The controller does not verify line-neutral
voltage between the generator and the paralleling bus
(neutral of the bus is not measured) so it is possible to
close the paralleling breaker into a short circuit. Floating
delta connections are also supported.
Sensing should be connected to the L1, L2, and L3
outputs of the generator, no sensing taps or
transformers are needed or desirable. Output leads
should pass through the CTs only once, just as they do in
wye configurations. 240 and 440 delta configurations
are accepted.
206 Section 12 Paralleling System Information
3500 controller supports
3500 controller supports
12.3.4 Single Phase
The Decision-Makerr
paralleling in a single-phase configuration, but it is
important that the metering inputs are connected
appropriately for accurate power metering. L1 current
should be connected to the I1 input to the controller, L2
current should be connected to the I2 input to the
controller, L1, L2, and L0 should also be connected to
the appropriate inputs to the controller. Bus metering
should also be connected to L1 and L2. Bus L3, Gen L3,
and I3 are unused in a single-phase configuration.
Although the synchronizing logic will synchronize and
allow the generator breakers to close, single-phase
connection type should never be used for an alternator
that is wired for three-phase, as there is no phase rotation
check in single-phase mode.
12.4 Functional Operation
Description
12.4.1 PGEN Communication
PGEN is a proprietary
communications protocol. Each node (controller) on the
network has a time slice to broadcast a packet
containing pertinent generator information, other time is
spent listening for packets from the other nodes. All
nodes on the PGEN network will send out at least one
packet every 50 ms.
12.4.2 Generator Startup
Crank Disconnect: When the engine speed exceeds
the crank disconnect speed, the engine is considered to
be started. The paralleling logic is only solved while the
engine is running.
Voltage Ramp: After the engine is running, the voltage
regulator begins ramping the target voltage up at the
rate specified by the Normal Voltage Ramp Rate
parameter. The voltage ramp will follow the Volts/Hz
curve if the engine speed takes longer to reach the
target than the voltage does.
Voltage and Frequency OK: The Voltage and
Frequency OK timer starts timing as soon as the
frequency and voltage of the generator are within the
range specified by the Acceptable Voltage Pickup and
the Acceptable Frequency Pickup parameters. The
voltage and frequency for the generator are considered
to be acceptable after the Voltage and Frequency OK
delay has expired.
3500 controller supports
scheduled broadcast
TP-6953 7/19