TriStar Manual

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specicvoltage,cur-

rent, or temperature limit. Alarm conditions are only displayed on the TriStar Meter.

Some basic fault conditions are reviewed below:

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. See section

8.0 for more information.

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.

Solar High Input Voltage

Solar input current will be limited as the array open circuit voltage approaches the 150 Volt maxi-

mum input voltage limit.

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 (R+Y / G+Y)

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 LED’s 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.