ProStar Testing Instructions

SunLight Testing Instructions Page 1 of 3 Revision 1.0

Morningstar Corporation 3 September 1999

Testing Morningstar SunLight Controllers

Notes:

- Due to the nature of the SunLight controllers, it is possible only to determine whether the

unit is functioning properly. It is not always apparent what component has failed or the

cause for the failure. It is left up to the technician to determine the cause for the controllers

failure based on evidence present at the site (i.e. burned leads, excessive loads, evidence of

short circuits on load leads, more PV current than the controller is rated for etc.)

- It is difficult to completely verify the operation of the SunLight controller in less than 2 full

days due to the nature of the controller. However the operation of the controller can be

verified to a 95% confidence level with the test procedures outlined below.

- The procedures outlined below assume a basic knowledge of electric circuits and the

necessary safety precautions to be used when working with live circuits present in solar

energy systems.

- All voltages will be given for a 12V nominal system. For a 24V nominal system, all voltages

should be double.

Recommended Tools:

- Digital Multi Meter (frequency and duty cycle measurements are helpful)

- Flat Bladed Screwdriver

- A lighting load (a type 1156 automotive brake lamp works well for 12V systems)

- A battery bank (of appropriate voltage for the controller)

- A solar array in full sun and/or a Power Supply (of appropriate voltage for the controller)

- Wire for connections to the SunLight.

Test Procedure:

1) Connect the battery and a load to the SunLight.

2) Set the load switch to any setting desired.

3) Verify the load works by pressing the test button.

4) Wait 5 minutes for the load to go off

5) Connect a power supply (set to 15V) or a PV panel placed in full sun to the Solar Input

Terminals (Terminals #4 and #3). Be sure to observe correct polarity.

PAGE 1
Testing Morningstar SunLight Controllers Notes: - Due to the nature of the SunLight controllers, it is possible only to determine whether the unit is functioning properly. It is not always apparent what component has failed or the cause for the failure. It is left up to the technician to determine the cause for the controllers failure based on evidence present at the site (i.e. burned leads, excessive loads, evidence of short circuits on load leads, more PV current than the controller is rated for etc.
PAGE 2
6) After a delay of 5-15minutes, the controller should be charging the battery. This can be verified by measuring the voltage drop between the PV+ terminal and the Battery+ terminal. If it is zero (Or less than .5Vdc) the controller is charging the battery in Bulk Charge mode. If you measure a DC voltage, switch your meter to AC voltage and see if an AC voltage is present. If an AC voltage is present, the SunLight is in the PWM mode and regulating the battery voltage.
PAGE 3
Some General Notes on SunLight Operation: • There is a delay built into the micro-controller that waits from 5-15 minutes before changing from day to night (or night to day). This is so the controller will not get fooled by dark storm clouds passing in the summer time, bright lights on the array at night from passing cars or trucks etc. What this means is, when you start up the controller and connect the array, there will be some time before the controller begins to charge the battery.