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TriStar MPPT Operator’s Manual
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Operation
4.5 Protections, Faults & Alarms
The TriStar MPPT 150V protections and automatic recovery are important features that ensure
the safe operation of the system. Additionally, the TriStar MPPT 150V features real-time self
diagnostics that report Fault and Alarm conditions as they occur.
Faults are events or conditions that require the TriStar MPPT 150V to cease operation. A Fault
usually occurs when a limit such as voltage, current, or temperature has been surpassed. Fault
conditions are indicated with unique LED sequences and are also displayed on the TriStar Meter.
Alarms are events or conditions that may require the TriStar MPPT 150V to modify operation.
Alarms are commonly used to alert the user that the controller is nearing a specific voltage,
current, or temperature limit. Alarm conditions are only displayed on the TriStar Meter.
Protections
Solar Overload
The TriStar MPPT 150V will limit battery current to the
Maximum Battery Current
rating. An
over-sized solar array will not operate at peak power. The solar array should be less than the
TriStar MPPT 150V
Nominal Maximum Input Power
rating for optimal performance. For more
information see the Nominal Maximum Input Power asterisk on p. 63.
Solar Short Circuit
The TriStar MPPT 150V will disconnect the solar input if a short circuit is detected in the solar
wiring. Charging automatically resumes when the short is cleared. No LED indication.
High Input Voltage Current Limit
The TriStar MPPT 150V will limit the solar input current as the solar array Voc approaches the
maximum input voltge rating. The array Voc should never exceed the 150 volt maximum input
voltage - see the array voltage de-rating graph in Appendix.
Very Low Battery Voltage
If battery discharges below ~7 Volts the controller will go into brownout and shut down. When
the battery voltage rises above the 8 Volt minimum operating voltage, the controller will restart.
Faults
Remote Temperature Sensor Failure (
G - R sequencing, with constant yellow
)
If a fault in the RTS (such as a short circuit, open circuit, loose terminal) occurs after the RTS has
been working, the LED’s will indicate a failure. However, if the controller is restarted with a failed
RTS, the controller may not detect that the RTS is connected, and the LEDs will not indicate a
problem. A TriStar meter or the PC software can be used to determine if an RTS is detected and
working properly.
Battery Voltage Sense Failure (
G - R sequencing, with constant yellow
)
If a fault in the battery sense connection (such as a short circuit, open circuit or loose terminal)
occurs after the battery sense has been working, the LEDs will indicate a failure. If the control-
ler is restarted with the failure still present, the controller may not detect that the battery sense is
connected and the LEDs will not indicate a fault. A TriStar meter or the PC software can be used
to determine if the battery sense is working properly.
Battery Over-Current (R / Y - G)
While rare, if battery charging current exceeds approximately 130% of the controller’s output
current rating, this fault can occur. The fault is generally related to fast, large battery voltage
transients (connecting a very heavy or capacitive load like an inverter) that are faster than the
controller can regulate and it shuts off to protect the circuitry. The controller will automatically
re-start in 10 seconds.
Settings (DIP) Switch Changed (R-Y-G sequencing)
If a settings switch is changed while there is power to the controller, the LEDs will begin sequenc-
ing and the solar input will disconnect. The controller must be re-started to clear the fault and
begin operation with the new settings.
Battery High Voltage Disconnect (G-R sequencing)
This fault is set when battery voltage is above normal operating limits. The controller will discon-
nect the solar input and set a High Voltage Disconnect fault. This fault is commonly caused by
other charging sources in the system charging the battery above the TriStar MPPT 150V regula-
tion voltage. When the battery voltage returns to normal levels, the fault will automatically clear.
Custom Settings Edit (R -Y- G sequencing)
A value has been modified in custom settings memory. The controller will stop charging and
indicate a fault condition. After all settings have been modified, the controller must be reset by
removing and then restoring power to the controller. The new programmed settings will be used
after the power reset.
