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silvercloud

G3600 ECM Control Strategies?

Hi there-wonder if anyone here can point me to some literature that could explain the electronic engine control strategies for a G3606 with the old ESS control system-actually would be interested to read about the ADEM 3 system as well.

 

Background: I am a relief plant/field operator here in Alberta. One of the companies I work for has a G3606 driving a 6 throw compressor in a CBM compressor station that is in the middle of having a hissy fit :-). It's one of the 1st off the line (3XF00017!) and still running the ESS electronics package and Heinzmann (?) actuators. It started crashing almost a month ago on multiple misfires/detonation/underspeed. We've gone through a pile of things including a full tuneup (new Cat plugs/combustion sensors/PC check valves/valve lash/tested coilpacks/ohmed out primary and combustion sensor leads), a compression test and borescope inspection for liner/piston/head condition and coolant leaks, some wiring repairs, exchanging the pressure module with a running but shut-in 3606 they have at another plant, changed the magneto to a remanufactured one, removed/cleaned/reinstalled crank position sensors, changed charge air temperature sensor, wastegate actuator replacement, fuel shutoff valve replacement, fuel pressure verification. I think I'm forgetting some things, but basically, it's had a lot of attention. At one point in time the only way to make it run at all was to leave it plugged into the Cat scan tool and locked in PC Cal mode-otherwise the fuel correction would start oscillating up and down and get progressively more aggressive until the unit crashed.Even with that, the actual burn times were all over the map. We have even tried taking throttle control away from the compressor PLC and fixing it on the Cat panel to eliminate a possible communication error between the 2. We've gotten it to the point that it will run for a period of time (anywhere from 2-5 days) and then out of the blue crash down again on multiple misfires and fuel quality compensation failure.

 

I assume that something is happening that's causing the ECM to lean out the A/F mixture enough to trigger the misfires and eventual stallout. This is why I'd like to learn what the ECM looks for & what inputs cause a change in A/F ratio.

 

Thanks
Jason

mikel
Posts: 515
Topics: 2
Kudos: 80
Solutions: 15
Registered: ‎12-10-2009

Re: G3600 ECM Control Strategies?

Probably your two best resources is the Operation and Maintenance Guide and the Troubleshooting Guide.  Unfortunately the information doesn't flow very well and you end up going back and forth quite a bit to get a good overall picture of how the control system actually operates.

 

On that vintage engine I have seen a couple of things that could contribute to the types of problems you're seeing,

 

An Actuator starting to fail, the Heinzmann actuators when they get old can start to drift with a constant command, best way to troubleshoot is using CAT ET and the datalog function, watch the actuator commands and see if they start doing something strange.

 

BTU potentiometer, had a few BTU pots that went erratic, caused a similar problem to what you describe, also had a failed speed brick (the analog to PWM convertor between the BTU pot and the ECM) do the same thing.

 

Also those early engines had piss poor wiring harnesses, the connections looked like birds had done the solder joints instead of skilled technicians, I still run into engines that those bad solder joints are causing problems. CAT did publish a list of replacement Amphenol connectors to service the harnesses that could help resolve the problems.

 

Maybe Al Hunt will weigh in, on gas compression 3600 engines he's likely the best possible resource still walking around.

 

Hope that helps, Mike L.

New member
silvercloud

Re: G3600 ECM Control Strategies?

Thanks for the reply & the suggestions. The BTU pot is an interesting thought-I know when I show up on a callout (unit is unmanned ~23 hours/day) the displayed BTU reading is at its previous setting-is it possible to drift but then come back? Would not surprise me at all to find a wiring issue as the connector at the fuel actuator was found to be bad on the initial service call. We do have spare actuators as we managed to acquire takeoffs from another company when they converted to the Hydrax actuator system-maybe time to try changing it out as a test. We are trying to find a takeoff ECM & timing box inhouse again from units upgraded to ADEM 3 as a last-ditch solution-with the price of gas right now it just doesn't make a lot of sense to throw a pile of new parts at it. Will see if we can come up with a speed brick to try as well. Again, thanks.

Jason
bme
Visitor
bme

Re: G3600 ECM Control Strategies?

Hi Mike,

I have read your responses on other topic and thought you may be the guy that can help answering my question. I appreciate your reply at your earliest convinience.

I am asked to come up with a working diapgram of a dual fuel (LPG & NG) genset that requires fuel switching on the fly.

The first concept is to have two separate fuel lines, each should have its own fuel lock off and pressure regualtor before it come together into the common mixer. I need to know what it takes (additional devices) to be able tto perform switch on the fly? With your experience, have you come across any such system? What is a complete diaphragm for this type of system to work?

Thanks in advance for your reply.

bme.

mikel
Posts: 515
Topics: 2
Kudos: 80
Solutions: 15
Registered: ‎12-10-2009

Re: G3600 ECM Control Strategies?

The Caterpillar Application and Installation Guide, in the section on gas engine fuel systems has details on recommended dual fuel systems.

 

Contact your local dealer for a current copy, you need to reference LEBW5336-00, look on page 18.

 

If your local dealer can't/won't help send me your email address and I'll email you a copy.

 

Mike L.

bme
Visitor
bme

Re: G3600 ECM Control Strategies?

Thanks Mike.

I will see if I can get some info per your note.

bme

AlH
Contributor
AlH

Re: G3600 ECM Control Strategies?

Jason,

Mike is right on about the wiring on an ESS G3600.  This is the weakest link on this version engine.  You didn't mention what the fault code(s) are when the engine shuts down.  This would be helpful information.

I suspect that your problem is really a wiring problem.  I had a G3606 near your s/n a couple of years ago with similar problems.  The cause was found to be in the wiring.  Loose connections can cause all sorts of strange reactions.  I would suggest that you carefully inspect each connection in all the engine junction boxes and the ESS remote panel which should be mounted off the skid to prevent vibration issues.  When you inspect the terminal connection, I would suggest that just pulling on the wire to see if it is tight is not enough; you should remove each wire and then reinstall it into the terminal and tighten the terminal screw.  Just because you can't seem to pull the wire out doesn't mean that a connection with integrity exists.

Secondly, carefully check all the ground connections.  Especially, you must have a good earth ground connection from the engine block to earth ground.  The normal connection is on the right front of the block where the negative side of the ignition coils terminate in the ground lug bolted to the engine. 

Thirdly, you might have electrical noise as the cause of the problem.  The Heinzman actuator can actually induce electrical noise into the control system.  That is why the fault code number and sequence of how multiple codes appear in the ECM window might be important to sort out your problem cause.

Try these items carefully and let's see what results you have.

Al H

Visitor
AGWestside

Re: G3600 ECM Control Strategies?

This is only partially in reply to Jason’s question about the G3606 ESS Control:

 

I am also hoping for answers to my two questions. I too am looking at upgrading to ADEM3’s with a TCP/IP Modbus data connection to our SCADA. We currently have two G3508s with EIS ignition control and a remote ESS interface panel containing a Status Control Panel (SCM) mounted on the engine/gas compressor skid. We have no Cat CCM, CIM, Relay, or Alarm Modules.

 

The only Caterpillar digital data networks available on these engine controls are the 3-wire (inc GND) bi-directional DDTC Link from the EIS, two uni-directional I/O links at the SCM, (one for input from the OP/WT Xducer, the other the ALM/CIM output that is not in use), and an RS-485 (also not in use) from the 179-9001 Pyro. I think I have a basic idea of what may be close to the method of data exchange in use on these different networks. The “one” wire SCM I/O looks like it might be similar to SAE J1850, the EIS DDL link something like J1939, and the Pyro two wire RS485 should be standard but I doubt if it utilizes Modbus. Can anyone tell me if I am close in assuming that Cat didn’t stray too far from the rest of the herd with the method on these links?

 

The big question is: Can we convert the limited data we now have from the EIS, SCM, and Pyro to TCP/IP Modbus with just one gateway device (so far Monico hasn’t provided a definitive answer to this), or do we replace the EIS, the SCM, and the Pyros with the ADEM3, Remote Operator Control Panel, new Pyros, and a Modbus gateway for about $17,000 per unit (parts only)? The latter seems like a no-brainer to me but I would like your input and hopefully some agreement before I take this to the big boss.

 

Thanks,

Jim       

AGJim
mikel
Posts: 515
Topics: 2
Kudos: 80
Solutions: 15
Registered: ‎12-10-2009

Re: G3600 ECM Control Strategies?

I have a couple of plants using CAT CCM's with the ESS control system, we get a pretty good chunk of the data at a reasonable (1 second average) update rate. Also have a number of landfill sites using a ZTR system tkaing data thru a CCM but the update isn't all that great.

 

I am curently getting ready to upgrade a sewage pump station with two early ESS engines from CCM to PL1000E.  It is not the easiest path but it looks like it will do what we want. 

 

The ESS system did not include pyrometer temps into any of the comms, however the newer CAT digital pyrometer has an RS485 ASCII output that can be converted and brought into a PLC or SCADA. I have used it on a number of sites and have been pretty happy with it.

 

Unfortunately CAT didn't think that data to external systems was that big a deal for many years, and frankly it is still one of the hardest engines to get data from without a LOT of work.

 

My experience with the Monico stuff has been mixed over the years, sometimes it does what I need, other times it hasn't meet expectations.

 

I will know more in a few weeks how the PL1000E works as a CCM replacement for ESS engines, as we are going from a Modbus RTU network to Modbus TCPIP, the reason for the change. I have used PL1000E's with newer product, including GCM32 engines in gas compression with pretty good results, so it can be done, just not easily. At least in my opinion.

 

So the short answer is no, not one device, you can use a PL1000E to get engine ECM and EIS data, no SCM data on data link, and no pyrometer data. My best performing systems have been based an Allen Bradley PLC with a Prosoft card, usually the ADM (Advanced Development Module) and use one port for the CCM data and the other for the pyro data.

 

Some other folks may have other experience, but in my case haven't seen anything I would call great for this, especially for the older control system.

 

Mike L.

AlH
Contributor
AlH

Re: G3600 ECM Control Strategies?

Cat currently uses the PL1000E for customers to use when acquiring the data from the engine control system to the system the customer is using, MODBUS being the most often used from my experience.

 

I agree with Mike in every area of comments and I know Mike has more experience with this subject than I do.  However, I would like to add a couple of things for consideration.

 

Cat does not support any Monico product so whatever Monico knows/develops is though "trial and error" working on a Cat control system and trying to figure out the data communication structure.

 

Whatever system or method you finally select, remember that you don't need all of the data to be "live real time" data.  You only need speed, engine oil pressure, maybe jacket water temperature to be live data.  All of the other data items can/should have a less frequent polling rate.  This will make the system operate more reliably.  If you ask for every bit of data at once or at the same live data rate, the result will probably that at some point the engine will shut down because the Cat data link becomes corrupted because it can't keep up with the data polling requests.  And from my experience, most customers just do not use all the data that they get off the Cat system.  It just fills up the data base files with no appreciably positive effect on achieving a better operating installation.

 

With these items to consider additionally, Mike is right on with performance observations and suggestions as to how to make the customer system work.

 

Al Hunt