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Technical FAQ
Lighting Problems - Flourescent Light Ballast Diagnosis
There are different types of lighting systems being used in True cabinets, so there will be different types of troubleshooting techniques that need to be used. The one common aspect in all of the lighting circuits is that the bulbs being used must be the same as the bulbs that were originally installed in the cabinet.

To test ballast determine which lighting system you are working on and follow steps below:
Electromagnetic rapid start flourescent light circuit - There are three different voltage tests.
Incoming or ballast supply voltage - Test at black and white wires going to ballast. You should read approximately 118 volts.
Filament voltage - Tested between red to red wires or blue to blue wires. Depending on which ballast you have you should get a reading between 2 and 5 volts with the bulbs out. Please call technical service with the ballast number to get the correct voltage reading.
High Voltage - Test between either red wire and either blue wire. Again depending on which ballast you are checking the voltage can range between 205 and 310 volts with the bulbs out. Please call technical service with the ballast number for the correct voltage reading.

Instant start electronic flourescent light circuit - (Note: A high impedance meter is required for testing this ballast) There are two different voltages to test.
Incoming or ballast supply - Test at the black and white wires going to the ballast. You should read approximately 118 volts.
High Voltage - Test between the red wires and any one of the blue wires with the bulbs out. You should read approximately 600 volts (+ or - 10%)

Preheat flourescent light circuit - Test voltages between pins on each end of the lamp. You should get approximately 118 volts from one pin on one end to one pin on the other. You can also check for continuity between the other pins on either end to the starter base. (To do this test make sure there is no voltage to the circuit and remove the starter from the base.) If both are OK change the bulb first and then change the starter.

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A qualified service technician must be used to perform these tests using extreme care because of the risk of electrocution if tests are not performed correctly.
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