Delay in EDG Starting

Have you read the Troubleshooting Section of the Manual? What does it indicate as possible causes for this symptom? That is the first place to start.

I agree with the most recent comment and would add: the ambient conditions of both the fuel and the generator have a great deal to do w/ starting performance. Diesels, in general, are very temperature sensitive. Heaters will help, if applicable. Another possibility would be the lift pump.

It sounds like possibly a fuel starvation issue. If it's starting under load, then maybe the initial load is too high. If it has an electronic governor, there may just be a setting to adjust to increase the starting ramp time. If it's a mechanical governor, have it serviced, then if the problem persists, try starting with less load, then switch the load in after it reaches full speed. The fuel filter could also be partially blocked. There could be may things causing this, but it's most likely in the fuel system.

Does it fail to fire off quickly or is it just very slow to come to speed?

Does it sound like it is miss firing?

If it synchronizes to the utility to load the generator, is it taking a long time to synchronize?

If after it synchronizes (if it does) or closes to the test load, does it take too long to load?

If it is failing to begin cranking quickly, you may possibly have a problem with the control logic.

If it starts cranking right away but does not start for several seconds, you may have a fuel control problem from any of several causes.

If it starts quickly and does not crank for a long time but is slow to accelerate, you may have governor problems.

If it starts quickly and does not crank for a long time but is slow to accelerate while obviously missing and jerking around, you may have a fuel supply problem.

If it starts and comes to speed quickly but will not take load once it connects to the load bus, you may have a fuel supply restriction or a carbon accumulation which is common with diesels which are run at very light or no load.

If it has a turbocharger, it may come up slower than normal and load but not make full load if the Turbocharger has seized and is acting as an air restriction rather than a compressor.

Let us know more about your symptoms and perhaps we can help.

TT3

If your engine is driving a Generator, it will always come up from zero to rated speed under zero electrical load conditions, that is with Generator Breaker open. Load will only be applied to the engine after it reaches rated speed (60Hz) and rated voltage, at which point the Generator Breaker closes, and the engine sees electrical load for the first time. The electrical load should therefore not be considered during the period of acceleration, as a reason why the engine would not accelerate within the expected time-frame. If it is an electronic governor, you should check whether anyone has increased the ramp time setting on the governor for the idle-to-rated speed ramp. If not, then verify that the governor output mechanical linkage to the fuel valve is moving through its full range(going fully open for max fuel) to the engine, during the acceleration period. If yes, then check that you have adequate fuel pressure and no fuel restrictions in the fuel path to the engine.

Thanks, some detailed symptoms are

• Reaches required 650 rpm with starting air in ~ 04 Sec.
• Achieved 1200 rpm immediately in ~07 Sec. and stuck at 1200 rpm for ~ 12 Sec.
• Reaches to 1500 rpm in ~ 22 Sec.
• Cranking and firing started quickly but take abnormal time at 1200 rpm.
• No abnormality is in synchronization & loading.

Have you done a thorough PM on this set?

Is it mechanical governor or electronic governor? If Electronic, I would be contacting the service representative as it seems to be slow to change modes from accelerate to synchronize. It could be several things from a very complicated controls issue to a simple tuning adjustment of the gain/proportional and/or Integral/Reset to speed up the tuning and get it to speed. It should not be hanging around 1200 since I assume the synchronous speed is 1500.

Did this problem start after recent service or some other work on or around the machine? I saw one diesel develop synchronization problems after an electrician stepped on the governor linkage and bent it. He straightened it by hand but it was still binding and made the speed unstable.

Before you issue the P.O. to the factory guys, it often pays to give things a quick look over to see if you can spot any obvious problem. The linkage looked fine to the electrician but the mechanic spotted it on his way up the ladder for the inspection. The machine was fixed and on-line in a half hour instead of waiting four days for the rep to arrive. ;)

Let us know what you find.

TT3

Hi

TT3

1. Engine type is 12 V, HSDO as fuel & sequential Turbo charger engine 03 groups of LP+HP.
2. This problem minimized in the 2^nd starting attempt just after 1^st attempt.
3. major jobs done on engine are (03 month ago:
1. Big end bearing replacement
2. Cylinder head 04 # overhauled & seat grinding performed.
3. Cylinder liner honing 04 #
4. Fuel injector nozzles testing & calibration
5. Compression pressure testing
6. Starting air valve testing

If it malfunctioned the first time but worked OK the second time, it could be because the engine was hot the second time or something like that. Have you tried it lately? It could have been missing due to air in the injection system or something. If that is the case and the system has purged itself, it may be fine now.

I would try it again while it is cold and see what it does.

TT3

Same behaviour of delay starting repeates when starting attempt is taken after a day or 02 days.

a:Sure gen initial engaging happens over 1350 rpm? If it starts at 1200 there's partial explanation

b.Does this behavior get any better on higher ambient temp? (Try noon time comparing to early morning)

c.Any info on engine oil viscosity, oil pressure gauge presence, time to reach normal value (dont give me the bulb)

d.Disconnect diesel return on first crank. Any bubbles?

e.Heavy metallic knock on first 15-20 seconds? High in the head or lower in case?

Before I get these answers my money is on lube.