06-27-2012 02:55 AM
I have a C18 generator which has been running fine, this morning I switched off the breakers to remove the load before shutting down for a service, once I removed the load the engine started to over rev and shut itself down. It's like the ecm didn't compensate after the load was removed, any idea's ?
07-08-2012 08:01 AM
Just a couple of questions for you: 1.) Is this C18 in a single unit standby configuration (no paralleling switchgear)? 2.) When was the generator installed? 3.) Have contacted your local CAT dealer?
07-12-2012 11:03 PM
How many per cent the genset have loaded? How many time has it got the problem?
I don't think the ECM failed. Pls check again after restart Control Panel & ECM.
Phu Thai CAT - Vietnam
10-09-2012 02:26 AM
I have the same problem here with a c18 generator,
it was running good under load, when the power was turned off it went into overspeed, after turning off and re-setting
it starts up, runs to 50hz if it hits 51hz it climbs to 54hz on its own and then shuts down.
i have replaced the injectors and done the trim codes, replaced the ecm, replaced the speed controller, i have cat et but there
are no fault codes except for overspeed.
any ideas what to check next would be great??
thanks in advance
12-13-2012 08:26 PM
we changed the potentiometer, still the same, we ran with load to 25%, when shut of power the generator rpm climbs to overspeed and shutsdown, we turn the potentiometer down and restart, then adjust to 50hz, runs stable, engine runs good, but same off load and high rpm.
any ideas would be a great help.
12-16-2012 08:00 PM
I see many Posts about this. The one response that made sense was did you contact the dealer? You dont want to overspped an engine. The bottom line is its not stated what type of device is providing the speed signal.. Is a a regular speed brick or is it a woodward control. Is it a emcp 3 or emcp 4? the regular speed brick is where the 2k 10 turn pot goes into. the same pot will also go into a wooward control. The reason you need a dealer will be because he can plug in ET and monitor the engine ECM when the unit is loded. and see position of throttle. he will also see desired throttle positon. When unloaded if the desired speed signal doesnt change but the rack position increases then it may be a problem with ECM. if however desired speed increases when unloaded then it will be the PWM device that is providing signal may. be faulty.
12-16-2012 08:06 PM
Thanks very much, we have et here and have used it, we also have trackindo here and tried them also but they dont know as they only sent mechanics and only have 1 electrician for these kinds of jobs, hard to get him but we are trying.
we will check the pwm, it is only overspeed when the power is turned off from the generator, on start up it is stable at 50hz, under load also is good and power output is good, only when load is turned off it overspeeds and dosent come down......it is wierd, as i said we had trackindo instal and flash another ecm, and also had them completely check the engine with nothing found etc.
thanks very much for the replies guys, we appreciate the help.
12-16-2012 08:21 PM
How much load are you putting on it? And if you have et hooked up can you see rack position? If loaded its at a high percentage..IE 85% - 100% then you may be overfueling..Also you can monitor the desired rack position without unit running. Move the pot through its paces watching the Et desired rack in the monitoring section.