Power Generation: Product Operation and Maintenance

[hmraju]

I am working 100MW diesel power plant. Heir all gen set D-3512B.

I don't understand What is the cylinder cutoff test? When cut off resell Not OK, we changed Injector. But I don't know what measure of cutoff test?

What do mean by CYLINDER CUTOFF TEST? Please write ans.

[dave10010]

The cylinder cutout test is used to diagnose a weak or failed injector or a miss-fire that could be caused by something other than the injector. The test disables each injector and measures the difference in the delivered fuel volume with the injector disabled compared to enabled. With the cylinder cutout, load on the remaining cylinders is higher and the delivered fuel volume increases to compensate for the disabled cylinder. If a failed injector is cut out, delivered fuel volume on the remaining cylinders will not change. You will get the same results if a cylinder is not firing due to some other mechanical problem, such as leaking valves or piston rings. The automatic cylinder cutout test in ET disables multiple cylinders during testing to add additional load to the remaining cylinders for more accurate results.

[wideglide058]

I can tell you we had same issue on d3508B marine gen set. Kept saying cyl 3 failed test, after  2 heads,2 injectors, ran external wiring harness from ecm, and numerous adjustments cat came back and said do cutout test by manually switching off one bank of cylinders than switching off one at a time and listen to verify. Back this up with your exhaust temps.  wish we knew at the time but all temps good and engine running fine