Manual

16 TT-1596 3/15
4.4 Perform the auto-discovery
procedure.
Note: This procedure is REQUIRED.
1. Close the circuit breakers on both generator sets
and in the APM (if equipped with the optional circuit
breaker kit).
2. Press OFF on generator set 2. Press RUN to start
generator set 1.
3. After generator 1 starts, the controller cycles
through the relays in the APM. This process is
necessary for the APM to recognize the output that
drives the contactor, which connects the generator
set to the paralleling bus.
Note: The contactor status will indicate that the
contactor is closed during the process, but
the status may display the wrong generator
until auto-discovery is complete.
4. Verify that the connection LED on the APM lights to
indicate that the generator set is connected. If the
correct output is detected, it will turn on, turn off,
turn on again and remain on. After successfully
closing the contactor that connects a generator to
the bus, the controller will remember which
contactor is associated with that generator.
5. Press OFF to stop the generator set 1. Press RUN
to start generator set 2. Repeat steps 3 and 4 for
the other generator in the system to verify the relay
cycling.
Troubleshooting Auto-Discovery
If the connection LED on the APM fails to illuminate or
the relays do not cycle, check the following:
D Check the wiring between the generator and the
APM. Pay special attention to the L1 and L2
connection.
D Check the connection of the sensing wire to V9 on the
generator wiring harness. See Figure 14.
D Verify that generator 1 is connected to contactor 1
and generator 2 is connected to contactor 2 in the
APM.
If the relays continue to cycle, even after the generator
source on the ATS has indicated availability, check the
wiring to both generator sets, especially the wiring from
V9A and V9B on the APM transformers to the V9
terminals on the generator controllers. This connection
is necessary for the auto-discovery of the output
contacts.
If the correct output is detected, it will turn on, turn off,
turn on again, and remain on. If the output continues to
cycle on and off, verify that L1 and L2 are connected
correctly from the generator to the APM. Verify that L1
and L2 are consistent throughout the APM. Make sure
that the wiring in the APM has not been modified – the
bus sensing needs to be accurate.
In SiteTecht, observe the Generator Voltage L2--L3
parameter. This voltage should match generator
voltage L1--L2 when the contactor is closed, and read 0
(zero) volts when the contactor is open. If the Voltage
L2--L3 parameter reads more than 200 volts when both
contactors are open, reverse the L1 and L2 connections
between that generator and the APM.