1. Technical Conference - Panama City Beach, Fl - 2002 Flame Rectification l Remember Ohm’s Law E = I X R

2. Technical Conference - Panama City Beach, Fl - 2002 Applied AC voltage + - ++ - Alternating Current Sine Wave

3. Technical Conference - Panama City Beach, Fl - 2002 Basic Electrical Circuit + - SOURCE CONDUCTOR LOAD CONTROL

4. Technical Conference - Panama City Beach, Fl - 2002 Flame Rectification circuit!  What devices are used for electrodes? äFlame rod äBurner

5. Technical Conference - Panama City Beach, Fl - 2002 l The Voltage Source is the Ignition Control l The “load” is the flame sensing circuit inside the control l The conductors are the electrodes already identified. l What acts as the “switch”? l The flame completes the circuit. Flame Rectification Circuit

6. Technical Conference - Panama City Beach, Fl - 2002 Flame Sense Circuit ä One electrode is larger than the other causing electron flow to be greater in one direction than in the other. ä Compare the burner size to the flame rod size.

7. Technical Conference - Panama City Beach, Fl - 2002 +0-+0- 5a5a Current flow when flame rod is positive + _ F G

8. Technical Conference - Panama City Beach, Fl - 2002 +0-+0- 1a1a Current flow when flame rod is negative + _ F G

9. Technical Conference - Panama City Beach, Fl - 2002 Applied AC voltage - ++ -  a  a Effect = 4  a pulsating DC Effective Flame Signal

10. Technical Conference - Panama City Beach, Fl - 2002 Remember Ohm’s Law ? What happens in a circuit if resistance increases and voltage stays the same? Flame Rectification Circuit

11. Technical Conference - Panama City Beach, Fl - 2002 Typical Flame Detection Current Need to measure AC  A as well as DC  A Typical in-shot burner DC current is 2-5  A with a 4-8  A AC leakage. DC current is less than 1  A and AC current is at or above 4  A 1.Flame signal is weak 2.Corrective action is required

12. Technical Conference - Panama City Beach, Fl - 2002 DC Current vs. AC Current

13. Technical Conference - Panama City Beach, Fl - 2002 DC Current vs. AC Current DC CURRENTAC CURRENTAC DROPOUT 0.53.9410.39 1.04.3717.28 1.54.8820.1 2.05.4520.30 2.56.2024.37 3.06.9524.20 3.58.2924.22

14. Technical Conference - Panama City Beach, Fl - 2002 Remember Ohm’s Law ? What happens in a circuit if resistance increases and voltage stays the same? What can affect the resistance in the circuit? What else can affect the flame signal? Flame Rectification Circuit

15. Technical Conference - Panama City Beach, Fl - 2002 Increased circuit resistances l Burner oxidation l Non-secure burner l Flame “lift off” l Loose wire connections l Contaminated flame sensor l Faulty grounds l No grounds l Reverse polarity