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iftikhar129
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Join Date: Dec 2011
Posts: 67

Reverse Power Issue With Cat Engines

12/31/2011 1:39 AM

At my plant, we have two standby diesel gensets(cat-3512, 01MW each). We normally operate both of thses gensets in parallel. We are facing problem of reverse power. When both of the gensets are in operation; genset one gets tripped on reverse power.

I did following troubleshooting


1. I checked the response of Inteligen (Comap>IGCU controller), checkecd its response of Speed regulation when Load charing(SRO), it is varing according to the requirement.


2. I cheked the cable from Speed controller(IG-PCLSM) to Speed Governor, it is ok.

3. I checked the speed governor response to actuator, it is ok. however we interchanged the speed governor woodword 2301A..

4. I also changed the actuator with the other engine.

5. I also interchanged the speed sensor(Mpu).

6. I also checked the cable from speed governor to actuator. it is ok.

Inspite of doing this lot of hardwork, the problem still persist. engine starts normally & some times it runs for 6 to senven hours & some times even more. then it gets tripped every time on reverse power.

One thing I want to add more that in the last trip, it remained running under speed at frequency of 28hz for 5 minutes after the reverse power protection opend the generator circuit breaker.

I would wellcome your valued suggestions to resolve the matter.
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SolarEagle
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#1

Re: Reverse Power Issue With Cat Engines

12/31/2011 6:37 AM

It sounds like you have a burnt set of contacts...

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Tornado
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#2

Re: Reverse Power Issue With Cat Engines

12/31/2011 5:31 PM

There might be a fuel delivery problem (clogged filter, etc.), such that the governor is acting properly to give more fuel, but unsuccessfully. If this generator then slows down (as under high loading), it will draw reverse power and trip out.

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Wal
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Join Date: Jun 2011
Location: Phnom Penh
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#3

Re: Reverse Power Issue With Cat Engines

01/01/2012 2:13 AM

Your approach was pretty thorough. I have to applaud you.

Refer to #2.

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John Gerke
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Join Date: Jun 2011
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Good Answers: 1
#4

Re: Reverse Power Issue With Cat Engines

01/01/2012 1:01 PM

Sounds like you have circulating current caused by excessive field current on one generator. The circulating current appears as an inductive load on the generator with the excessive field current and as a capacitive load on the other generator. Is a paralleling module, such as the Basler APM 2000, being used with the voltage regulators.
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engineertony
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Join Date: May 2011
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#5

Re: Reverse Power Issue With Cat Engines

01/01/2012 2:13 PM

If you can borrow a logger of some kind, and monitor what's happening, you might find the source of the problem. We used to have such a device to see what breaker tripped first in a large shutdown, so one breaker causes another to trip and so on, but the logger shows what happened first even to a fraction of a second.

Genset number one can only have reverse power if it isn't being driven hard enough, so that means not enough fuel, the actuator from the woodward is not opening the fuel enough, or it's not getting the right information from the controller telling it to open the fuel to number 1 genset.

Is your controller doing load sharing based on CTs and load currents, you imply that it might be based on regulation, sensing the relative droop on each set. Bit beyond me I've no experience of this inteligen controller, but I would start with researching the manual & data on this controller, get the principle clear of what it is tryng to do. It has to know the load on each of the two gensets and then tell the woodward governors to control the fuel to maintain that power shared between the two sets.

At a guess I would think a dirty contact, a loose connection, at the magnetic pickup, or any of the controls. Try each terminal, clean and reconnect tightly. If it only happens with genset 1, even when all the controls are swapped over, then it has to be in the fuel line to genset 1 or another engine problem, fuel pump, injectors etc.

I don't understand how your number genset 1 can run at 28 Hz for 5 mins, what was number 2 doing? Surely not 50 Hz or 60 Hz.
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Wal
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#6

Re: Reverse Power Issue With Cat Engines

01/02/2012 12:32 AM

Just had a thought.

That 28Hz for 5 minutes could be a cool down period before stop.

Is this being improperly invoked without (normal) command?

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engineertony
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#7

Re: Reverse Power Issue With Cat Engines

01/02/2012 7:38 PM

Wal, Good thinking, I believe the breaker was tripped & the alternator disconnected, but as you say the engine has a run down timer of some kind.
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iftikhar129
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Join Date: Dec 2011
Posts: 67
#9
In reply to #7

Re: Reverse Power Issue With Cat Engines

11/22/2012 5:49 AM

issue solved long ago........

it was due to the contact damage of base of speed control relay.......
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Wal
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#10
In reply to #9

Re: Reverse Power Issue With Cat Engines

11/22/2012 6:37 AM

Thanks for letting us know.

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Nickpour
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Join Date: Mar 2012
Posts: 1
#8

Re: Reverse Power Issue With Cat Engines

11/21/2012 6:08 PM

Hi

please adjust gane nod of 2301A speed controler

I had problem like this.
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engineertony (2); iftikhar129 (1); John Gerke (1); Nickpour (1); SolarEagle (1); Tornado (1); Wal (3)

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