Blue Smoke upon Generator block load start
Blue Smoke upon Generator block load start
(OP)
Hello everyone,
I recently commissioned a Kohler 500kW diesel generator set.
During the start-up the generator was block loaded with about 100kW and I notied some blue smoke in the exhaust.
Although it was faint, it was there for about 1-2 minutes and then dispersed.
Is this normal? I know blue smoke is obviously burnt oil, however how much should be apparent upon start-up, if any?
What are some possible causes:
1. Loose piston rings?
2. Valve timing?
Thanks for your help.
Regards,
RK.
I recently commissioned a Kohler 500kW diesel generator set.
During the start-up the generator was block loaded with about 100kW and I notied some blue smoke in the exhaust.
Although it was faint, it was there for about 1-2 minutes and then dispersed.
Is this normal? I know blue smoke is obviously burnt oil, however how much should be apparent upon start-up, if any?
What are some possible causes:
1. Loose piston rings?
2. Valve timing?
Thanks for your help.
Regards,
RK.





RE: Blue Smoke upon Generator block load start
I have seen some puff of smoke and change engine noise, when applying 100% block loads. Even that should not last more than a few seconds (4-6).
More importantly what happens to voltage and frequency. How fast do the recover? That is the real test. But you may have more basic fuel burning issue.
Rafiq Bulsara
http://www.srengineersct.com
RE: Blue Smoke upon Generator block load start
Rafiq Bulsara
http://www.srengineersct.com
RE: Blue Smoke upon Generator block load start
No the genset came up to speed and voltage within its operating limits and assumed the load with no problems except for the fact that there was a hint of blue in the exhuast for about 1-2 minutes under 100kW load.
RE: Blue Smoke upon Generator block load start
A new engine may have oil collected from assembly in some areas that started to burn off as engine warmed. A used engine may have had oil and fuel from previous low load running collected in the manifolds.
To fully investigate, I think you need to run the engine at or near full load for enough time to get it up to temp and stable, then run long enough to burn out any posible storage lube or coatings, let the smoke stop coming off the manifolds, turbos and other hot areas, then shut it down, let it sit overnight and try starting again. See if the startup blue smoke returns.
Mike L.
RE: Blue Smoke upon Generator block load start
Rafiq Bulsara
http://www.srengineersct.com
RE: Blue Smoke upon Generator block load start
The worst case was an unattended set with auto start and a light load. This set pumped enough oil past the rings that it eventually shut down on low oil pressure. The set had a further series of misfortunes and misadventures and was eventually rebuilt with only a few hundred hours. Then about 10 years ago it went into storage. About six months ago, it was dusted off and put back into service. It was working well when I left the site.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Blue Smoke upon Generator block load start
RE: Blue Smoke upon Generator block load start
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Blue Smoke upon Generator block load start
Going off topic however still with the same general Generator applications.
I understand that a Generator is rated for step load and block load applications, in this case 500kW.
My question is in most instances these types of generators are used for emergency power applications, e.g where the local utility has blacked out and a call is made for the gens to start-up.
In these situations, the generator is ramped up to speed and voltage prior to a downstream ATS transferring to the generator source.
My question, in an application where the generator is shut down for any reason while applying load.
The load is essentially there waiting for a source.
So if the generator is restarted, the downstream ATS is already transferred to the generator source, will the generator still come up to speed and voltage as spec'd with the block load already on its bus?
Thanks,
RK.
RE: Blue Smoke upon Generator block load start