Rockwell Automation 1748 DataSite Configured Panel Installation Instructions - Manual (Page 38)

Publication 1748-IN001B-EN-P - May 2009
38 Troubleshooting
Step 4: Test condition of power transistors in solar controller
Test the condition of the power transistors in the solar controller.
1. With the solar controller completely disconnected from the DataSite
configured panel, make these connections.
a. Use a variable power supply set to 20V DC, 0.5 mA.
b. Connect the + VDC Power Supply terminal to the ARRAY(+) input
terminal of the solar charge controller (3).
c. Connect the Common Power Supply terminal to the ARRAY (-)
input terminal of the solar charge controller (3).
2. Measure the voltage at BATT (+) and BATT (-) terminals of the solar
charge controller (3). The reading should be approximately 14.3V.
• If the reading is high (16…20V), the power transistor has failed
short.
• If the reading is low (0…5V), the power transistor has failed open.
• If the transistor is open or shorted, replace the solar controller.
Step 5: Test condition of blocking diode in solar controller
Test the condition of the blocking diode in the solar controller.
1. With the solar controller completely disconnected from the DataSite
configured panel, make these connections.
a. Use a variable power supply set to 20V DC, 0.5 mA.
b. Connect the + VDC Power Supply terminal to the ARRAY (+) input
terminal of the solar controller.
c. Connect the Common Power Supply terminal to the BATT (+) input
terminal of the solar controller.
2. Measure the voltage at ARRAY (+) and BATT (+).
The reading should be around 0.3…0.6V.
• A very high reading (16…20V) indicates an open blocking diode.
• A very low reading (0…0.2V) indicates a shorted blocking diode.
• If the diode is open or shorted, replace the solar controller.