WARNING: The DC Switch is rated to break loads under normal
operating conditions. However, a DC short circuit could be hazardous,
and the following procedures should be followed before turning OFF
the DC Switch under fault conditions.
If there is a fault and it is safe to access the inverter:
1. Read/record the fault code(s) displayed on the LCD interface.
2. Turn OFF the inverter via the LCD/Keypad or Remote access.
3. Turn OFF the AC feed breaker.
4. Turn OFF the AC Switch.
5. If possible, read the DC MPPT currents displayed on the LCD interface:
a. If the MPPT current is <30A or the irradiation is obviously low, turn OFF the
DC switch.
b. If it is safe to open the wire-box, proceed with troubleshooting procedures
listed in Table 7-1. Make sure appropriate safety precautions and PPE are
used.
6. If it is not possible to read the DC MPPT currents through the LCD interface, and
no fire, smoke, or voltage (AC or DC) to ground is present in the enclosure:
a. Follow general safety practices including PPE to open the wire-box.
b. Measure the DC current on each string. If zero, open the fuse holder for
each string reading approximately zero amps.
c. If the DC current is >0.25A, do not open the fuse holder.
d. When all possible fuses are open, measure the total MPPT current. If it is
<30A, turn OFF the DC switch.
e. If turning OFF the DC switch causes smoke, then (if safe) turn the DC
switch back ON and wait until low irradiation ~30min prior to sunset to
continue troubleshooting.
If there is a fault and it is unsafe to access the inverter:
1. Notify someone else. Initiate emergency mitigation plan if necessary. a. If smoke
or fire exists, procure a fire extinguisher.
2. If a fire has escaped the inverter enclosure – notify 911 immediately!
3. Turn OFF the AC feed breaker as soon as possible/safe.
4. If safe but conditions are deteriorating, consider:
a. Using the fire extinguisher.
b. Cutting the string conductors – one cable at a time with insulated cutters
(while wearing appropriate PPE).
5. Monitor conditions until low irradiation ~30min prior to sunset. If safe, turn
OFF AC and DC switches on the inverter and proceed with normal
troubleshooting procedures listed in Table 7-1.