Manual

Troubleshooting
56 900-0253-01-00 Rev A
Table 7 Troubleshooting
Symptom Remedy
Unit not operating;
unit had worked
normally before;
normal light
conditions.

Check the charging stage. Check other controllers (if present). If the batteries
are nearly charged, one controller may taper off (in the Absorption or Float stage)
while the other(s) complete the charge.

High temperature fault. Check the controller temperature. The FLEXmax 100 will
stop functioning at an
Output FETs
reading of 90°C. The system display
Over
Temperature
error will indicate
Y
. See page 38 to check all items.

High V
oc
fault. Check PV array voltage. If the open-circuit voltage (V
oc
) is too
high, the controller cannot safely operate. The system display
VOC Too High
error will indicate
Y
(see page 38). The FLEXmax 100 will automatically restart
operation once the V
oc
decreases to a safe level.
Upper limits: 24-volt system = 275 Vdc, 36-volt system = 283 Vdc,
48-volt system = 290 Vdc. See page 68 for more information.
CAUTION: Hazard to Equipment
Voltages in excess of 300 Vdc are likely to damage the FLEXmax 100.
The PV array should be designed to avoid ever reaching these voltages.

Module-level electronics may be interfering with the system (see page 26).
Consult the literature or manufacturer of any third-party products.
Unit not producing
expected power.

Check PV and battery voltages. If they are varying widely, the controller may be
in the process of an MPPT sweep. It should settle on a stable power point and
produce normally again after a short time.

Check PV conditions. Clouds, shading, or dirty modules cause poor performance.

Check battery conditions and charging stage. If the batteries are charged
(if the controller is in the Absorbing or Float stage), the controller will produce only
enough power to regulate the voltage at those set points. Less power is required.

Determine the specified short-circuit current of the PV array. The MPP current is
related to this number. Measure to determine if the short-circuit current is in the
expected range. Array or wiring problems may restrict the available power.

Check the PV array temperature. At high temperatures, the maximum power point
voltage may be near or lower than the battery voltage.

Check FLEXmax 100 external temperature. The output is derated above ambient
temperatures of 25°C (77°F). Also check FLEXmax 100 internal temperature
using the system display. See page 38.
If a temperature reading is greater than 142°C or less than –40°C, a sensor
may have failed. The
Reduced Performance
error will show
Y
(see page 38).
NOTE
:
If the temperature is high, ensure the fan is running. Check the heatsink.
This may require dismounting the controller. If the heatsink is blocked with mud,
organic material, etc., the controller will not receive normal ventilation. Clean it by
scraping between the fins with a thin wooden stick. Spraying is not recommended.

Module-level electronics may be interfering with the system (see page 26).
Consult the literature or manufacturer of any third-party products.
Unit not operating;
red F AULT LED
indicator.

Solid: Ground fault. Remove all sources of power from the system. The detection
circuit has sensed an open connection on the GFDI fuse (see page 13). The system
display
GFDI Fault
will show
Y
(see page 38). Check the fuse and the bonding
jumper (see page 12). Make certain each is installed according to the instructions.
Make certain the terminal bus bar is connected to earth ground (see pages 12 and
16). Inspect the rest of the system for grounding problems or shorted connections.

Flashing: Arc fault. This may indicate incorrect installation (see pages 16 and 21).
Remove battery power and wait for all LED indicators to turn off. Apply battery
power again. The arc fault card will perform a new self-test. If the fault is still
indicated, it may be necessary to troubleshoot the PV array wiring to find a
physical problem.