WARNING:
ALWAYS DISCONNECT AC POWER BEFORE DISCONNECTING PV MODULE WIRES
FROM BDM-300X2. THE AC CONNECTOR OF THE FIRST BDM-300X2 IN A BRANCH CIRCUIT IS
SUITABLE AS A DISCONNECTING MEANS ONCE THE AC BRANCH CIRCUIT BREAKER IN THE LOAD
CENTER HAS BEEN OPENED.
LED indica
�o
n
o
f err
o
r
•
err
o
r m
o
de (except f
o
r gr
o
unding err
o
r)
The LED light
fl
ashes in
red
color.
•
NOT
c
o
mmunica
�
ng with BDG-256, and with n
o
err
o
r
The LED light
fl
ashes in
orange
color.
•
gr
o
unding fault
The LED light is in
solid red
color.
Tr
o
ublesh
oo�
ng an in
o
perable BDM-250
To troubleshoot an inoperable BDM-300X2, follow the steps in the order shown:
1. Check the connec
�
on to the u
�
lity grid. Verify that the u
�li
ty voltage and
frequency are within allowable ranges shown in the label of BDM-300X2.
2. Verify u
�li
ty power is present at the inverter in ques
�
on by removing AC, then DC
power. Never disconnect the DC wires while the BDM-300X2 is producing power.
Re-connect the DC module connectors, and then watch for the LED blinks.
3. Check the AC branch circuit interconnec
�
on harness between all the BDM-300X2.
Verify that each inverter is energized by the u
�
lity grid as described in the
previous step.
4. Make sure that any AC disconnects are func
�
oning properly and are closed.
5. Verify the PV module DC voltage is within the allowable range shown in the label
of BDM-300X2.
6. Check the DC connec
�
ons between the BDM-300X2 and the PV module.
7. PLC signal quality may be checked through the interface on the BDG-256 gateway.
If the PLC signal is weak, it might be due to the distance between the micro
inverters and the gateway. It may also be caused by the interference from other
electronic devices. In most cases, signal quality may be signi
fi
cantly improved by
moving the BDG-256 to closer to the micro inverter arrays, and/or farther away
from other interferers. In some cases, a signal
fil
ter (LCF) may be installed to
reduce the interference to PLC communica
�
on. If there are two or more
separate BDM systems close by, it is highly recommended to install LCF for each
micro inverter system to block interference from adjacent other systems.
7. If the problem persists, please call customer support at NEP.
WARNING:
DO NOT ATTEMPT TO REPAIR THE BDM-300X2; IT CONTAINS NO USER-
SERVICEABLE PARTS. IF TROUBLESHOOTING METHODS FAIL, PLEASE RETURN THE BDM-300X2
TO YOUR DISTRIBUTOR FOR MAINTENANCE.
Disc
o
nnec
�
ng a BDM-300X2 fr
o
m the PV M
o
dule
To ensure the BDM-300X2 is not disconnected from the PV modules under load,
adhere to the following disconnec
�
on steps in the order shown:
1. Disconnect the AC by opening the branch circuit breaker.
2. Disconnect the
fi
rst AC connector in the branch circuit.
3. Cover the module with an opaque cover.
4. Using a DC current probe, verify there is no current
fl
owing in the DC wires between
the PV module and the BDM-300X2.
5. Care should be taken when measuring DC currents, most clamp-on meters must be
zeroed
fi
rst and tend to dri
�
with
�
me.
6. Disconnect the PV module DC wire connectors from the BDM-300X2.
7. Remove the BDM-300X2 from the PV array racking.
Installing a replacement BDM-300X2
1. A
�
ach the replacement BDM-300X2 to the PV module racking using hardware
recommended by your module racking vendor
2. Connect the AC cable of the replacement BDM-300X2 and the neighboring BDM-
300X2 to complete the branch circuit connec
�
ons.
3. Complete the connec
�
on map and connect the PV Modules.
1) Complete the connec
�
on map
2) Each BDM-300X2 has a removable serial number located on the moun
�
ng plate.
Enter this serial number into a BDG-256, and correspond it to a number in the
connec
�
on map.
3) Connect the PV Modules
4) Completely install all BDM-300X2 and all system inter-wiring connec
�
ons prior to
installing the PV modules.
a) Mount the PV modules above their corresponding BDM-300X2. Each BDM-
300X2 comes with two oppositely sexed DC connectors.
b) First connect the posi
�v
e DC wire from the PV module to the nega
�
vely
marked DC connector (male pin) of the BDM-300X2. Then connect the nega
�v
e
DC wire from the PV module to the posi
�v
ely marked DC connector (female
socket) of the BDM-300X2. Repeat for all remaining PV modules using one
BDM-300X2 for each module.
4. Replace the old PLC_ID in the BDG-256 gateway with the new PLC_ID of
the replacement micro inverter.
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