Setting the Timing of the Digital Ignition System
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| Illustration 1 | g00761355 |
Front view and side view of the timing control (1) "TIMING SWITCH" (2) "APPLICATION SWITCH" | |
The timing control has a "TIMING SWITCH" (1) and an "APPLICATION SWITCH" (2) . The "APPLICATION SWITCH" must be set to the engine model that is controlled. The switch must also be set to the timing range that is appropriate for the fuel that is consumed. The "TIMING SWITCH" is used to fine tune the ignition timing. Use the following procedure to set the ignition timing.
- Determine the correct ignition timing for the fuel.
- Obtain a fuel analysis.
- Enter the data from the fuel analysis into the Caterpillar Software Program, LEKQ6378, "Methane Number Program".
- Refer to Engine Performance, LEBQ6483, "G3400 Generator Set", "Fuel Usage Guide" or consult with your Caterpillar dealer in order to determine the desired ignition timing.
- Use the label for the "APPLICATION SWITCH" to choose the correct position for the switch. Set the switch at the lowest possible range for the desired timing.
Table 2 is an example of the settings that are listed on the label for the "APPLICATION SWITCH".
Show/hide tableTable 1 Example Settings of the Application Switch A = G3412 10 to 25 degrees BTC B = G3306/ G3406 10 to 25 degrees BTC C = G3408 10 to 25 degrees BTC D = G3412 20 to 35 degrees BTC E = G3306/ G3406 20 to 35 degrees BTC F = G3408 20 to 35 degrees BTC Recommendations for setting the "APPLICATION SWITCH" ( G3406 Engines)
For G3406 Engines, the "APPLICATION SWITCH" must be set to "B" or "E".
For a G3406 Engine with a desired ignition timing of 19 degrees BTC or less, the switch must be set to "B".
A G3406 Engine may have a desired ignition timing between 20 to 25 degrees BTC. The "APPLICATION SWITCH" could be set to "B" or "E". However, setting the switch to the lowest possible range for the desired timing is recommended. In this case, set the switch to "B".
For a G3406 Engine with a desired ignition timing of 26 degrees BTC or more, the switch must be set to "E".
Recommendations for setting the "APPLICATION SWITCH" ( G3412 Engines)
For G3412 Engines, the "APPLICATION SWITCH" must be set to "A" or "D".
For a G3412 Engine with a desired ignition timing of 19 degrees BTC or less, the switch must be set to "A".
A G3412 Engine may have a desired ignition timing between 20 to 25 degrees BTC. The "APPLICATION SWITCH" could be set to "A" or "D". However, setting the switch to the lowest possible range for the desired timing is recommended. In this case, set the switch to "A".
For a G3412 Engine with a desired ignition timing of 26 degrees BTC or more, the switch must be set to "D".
| NOTICE |
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Do not change the setting of the "APPLICATION" switch during engine operation. An engine shutdown can occur and/or the engine can be damaged. Always shut the engine OFF before you change the setting of the "APPLICATION" switch. |
- Set the timing switch to 15. Then move the switch to the setting that corresponds with the desired timing.
Examples for setting the "TIMING SWITCH" ( G3406 Engines)
A G3406 Engine has a desired ignition timing of 19 degrees BTC. The "APPLICATION SWITCH" is set to "B" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 6 positions toward "0". This corresponds with a desired timing of 19 degrees BTC.
A G3406 Engine has a desired ignition timing of 23 degrees BTC. The "APPLICATION SWITCH" is set to "B" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 2 positions toward "0". This corresponds with a desired timing of 23 degrees BTC.
A G3406 Engine has a desired ignition timing of 26 degrees BTC. The "APPLICATION SWITCH" is set to "E" (20 to 35 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 35 degrees BTC. Move the "TIMING SWITCH" for 9 positions toward "0". This corresponds with a desired timing of 26 degrees BTC.
Examples for setting the "TIMING SWITCH" ( G3412 Engines)
A G3412 Engine has a desired ignition timing of 19 degrees BTC. The "APPLICATION SWITCH" is set to "A" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 6 positions toward "0". This corresponds with a desired timing of 19 degrees BTC.
A G3412 Engine has a desired ignition timing of 23 degrees BTC. The "APPLICATION SWITCH" is set to "A" (10 to 25 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 25 degrees BTC. Move the "TIMING SWITCH" for 2 positions toward "0". This corresponds with a desired timing of 23 degrees BTC.
A G3412 Engine has a desired ignition timing of 26 degrees BTC. The "APPLICATION SWITCH" is set to "D" (20 to 35 degrees BTC). A "TIMING SWITCH" setting of "15" corresponds to a desired timing of 35 degrees BTC. Move the "TIMING SWITCH" for 9 positions toward "0". This corresponds with a desired timing of 26 degrees BTC.
| NOTICE |
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The "TIMING SWITCH" can be damaged if the switch is turned directly between the "0" position and the "15" position. Do not turn the "TIMING SWITCH" between these positions in either direction. |
Note: The "TIMING SWITCH" is graduated in increments from "0" to "15". The switch is fully advanced at "15". The timing is retarded by one degree per each mark as the switch is moved toward zero.
- Start the engine. Operate the engine at rated speed. Verify the ignition timing with a timing light.
Adjust the "TIMING SWITCH", if necessary. This is a small adjustment of only one or two positions in either direction. Adjust the switch in order to maintain the correct timing within 1/2 degree.
Note: Do not check the timing at low idle speed.
- Install caps (3) for the switches. Thread lockwire (4) through the holes in both caps. Secure the lockwires with wire seal (5) .
This will help prevent unauthorized tampering of the setting for the ignition timing.
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| Illustration 2 | g00762284 |
(3) Two caps (4) Lockwire (5) Wire seal | |