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NORA Oilheat Technicians Manual

versions for retrofit applications, depending on the mounting plate used. Output voltages of between 14,000 volts and 20,000 volts peak with amperages between 16 MA to 45 MA respectively, on the secondary coil, are considered normal, Figure 9-7. A solid state ignitor is a radical Figure 9-7: Ignitors departure from the traditional ignition transformers commonly used on oilburners. Solid state ignitors eliminate transformer design shortcomings. Ignitors utilize a solid state printed circuit board with what is called a ‘tank mechanism.’ This technology allows the ignitor to have a more constant output if the input voltage decreases. Therefore, we have fewer problems with voltage drops. Ignitors are insulated with epoxy, not tar. Epoxy is virtually resistant to heat and will not melt on the combustion head assembly. This same epoxy makes the ignitor virtually impervious to moisture. Electrical consumption from an ignitor is 30 to 50 watts, much less than the transformer. Ignitors are made from solid state electronic components and are truly ignition control systems. Testing electronic ignitor systems Since these units contain solid-state devices such as transistors, their troubleshooting and servicing should be done to manufacturers’ recommendations. Do not use a transformer tester to test electronic ignitors. Doing so will give you an inaccurate measurement and may harm the ignitor and tester. Testing electronic ignitor systems is different from testing ignition transformers because ignitors utilize a high frequency output. The cycling operations of a solid state ignition system are 20,000 times per second. Standard AC transformers cycle at 60 times per second. This is the reason you cannot test a solid state ignitor with a standard ignition transformer tester. The testing of electronic ignitors is more complicated than testing the iron-core transformer. Before you perform any of these tests, make sure the manufacturer approves of the test, and be extra careful not to directly short the terminals without a spark between them. In many cases, it will short out the ignitor and destroy its internal circuitry. Keep in mind that ignitors are not merely a pair of coils, but rather a complex electronic device made up of several electronic circuits and components. The first basic test for ignitors is to place an ohmmeter across the ignitor output terminals with the power off and measure Chapter 9 Ignition Systems 9-10 Ignition Systems


NORA Oilheat Technicians Manual
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