08-20-2012 11:05 AM
These problems with the G3600 with the ESS control has historically been almost always related to the wiring system. There are many wires and terminals which are susceptible to the engine vibration. When the integrity of the continuity of the control wiring fails, the ECM cannot control the engine as desired. That is one of the best benefits of converting to the ADEM 3 control system; reliability.
Another improvement of the A3 control strategy is the additional air/fuel ratio control at the low load operating mode. Cat calls this the "Exhaust Temperature Feedback Mode" and operates when the engine is operating at less than 40% load. The ECM uses the choke to control the air/fuel ratio control in this mode.
The most important thing for the G3600 to achieve reliable performance is to have the engine correctly setup; the PC CAL procedure must be performed correctly and the engine must be in good mechanical condition. The inlet, exhaust, and most importantly, the gas admission valve lash adjustments must be correctly adjusted. The combustion feedback system must be is good condition. The engine cannot be correctly tuned if there is excessive misfire; this MUST be fixed first before attempting to tune the engine. Service Manual RENR5908-11 and later issues have the correct tuning procedure listed in the section "BTU and Precombustion Chamber Adjustments". If you follow this procedure on a good mechanical condition, the engine should perform as well as it can.
If the G3600 ESS operates at less than 50% most of the time, the ECM cannot maintain the correct air/fuel ratio as the choke is controlled to a fixed position; there is no feedback. Under these operating conditions, I recommend that the G3600 ESS be converted to the A3 control system for better air/fuel ratio control under 40% load. The air/fuel ratio will be better controlled because the ECM is using the exhaust temperature as feedback to dynamically the choke to control air/fuel ratio. You will have to tweak the A3 system for the best results when operating continuously below 40% load.
If you have an engine with misfire, and are running under a high load, this misfire can cause the other cylinders to experience detonation. When this happens, the indicated load also goes up as the engine momentarily does use more fuel to compensate for the cylinder misfire (loss of horsepower) when it occurs.
I hope this helps understand some of these problems with the ESS control system. I have seen G3600 ESS availability achieve 98+% availability but it usually takes a lot of time, keeping the wiring harness in the best integrity (no shorts or loose connections). The A3 control systems easily achieves 98+% run time because the integrity of the A3 wiring harnesses is at a much higher level than the ESS wiring harnesses.
05-11-2012 06:58 AM
I have a similar problem ..
i use number G3608 driving pumps . all up 4WF-68 , using hydrax actuator system , ESS , no magneto the 24 vdc is comming from external source .
the errors are detonation (325-00) , lose of power (insuficeint boost 106-01) , misfire errors (529-02 , 529-13).
it seems it all goes around the air/fuel ratio and the way the control system manage it , we didn't try alot of changes and tests like SILVERCLOUD (only check valve and spark plug change , actuators links) but i found adjusting governer affects the errors in a way that if you remove the detonatio then the misfire and 106-01 appears , vise versa !!!!
these errors give me a headache , last thing i found if you adjust the BTU to a low value , i mean much low the actual one , the engine runs with only detonation from time to time , as the low btu makes the engine calculate low air/fuel ratio which in turn means that it needs less amount of air to burn that low quality fuel then it demands a low pressure from the turbo charger (wast gate) , so it will not requir alot of power from exhaust that in turns mean that if you have misfire in some cylinders it won't be much problem as on demand for hi inlet air prussure , also if you have moderate load the engine will never go above the 50% load percent , because the engine takes the demanded air inlet pressure as indication to the load (CMS gauge #6) , and the engine gos into feedback mode only when engine load is steady for couple of minutes above 50% , so the engine in this case will feel the load much less and behave like as it's in the PC CAL mode (taking the inlet air as indication to the load is a big mistake in this engine as i think).
low BTU result in highr emissions and the detonation still exist from time to time specially when the slight change in load , which make me think around the gas governer agian , at the present i try to keep the engine load under 50% by low BTU and try to make the work required with more units ( use two units at same time to deliver the required output instead of one to keep each under 50% load.
but still don't exactly understand where is the exact problem although i'm sure it's about the air/fuel ratio control method.
i 'll be happy if this discussion about that error comes with a solution. thanx
04-07-2012 10:28 PM
I forgot to address the G3500 EIS configuration. These engines can be upgraded to ADEM 3, either as the NTE 2 gm/NOx version. This version does not meet the current NSPS rules in the US for emissions.
Or the Bbbbb3500 EIS can be converted to the later G3500B configuration which has a 0.5 gm/NOx or a 1.0 gm/NOx rating. The upgrade to the G3500B configuration is much more expensive because it is more than just a control system/wiring upgrade. The G3500B conversion also includes, cylinder heads, turbochargers, exhaust manifolds, engine oil cooler, ADEM 3 control system and wiring, new fuel system, new two stage aftercooler system, new coolant lines, new pistons, and other supporting iron for these major components. A number of engines have been upgraded to the G3500B configuration.
04-07-2012 10:21 PM
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.
04-07-2012 08:03 PM
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.
04-06-2012 11:34 PM
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.
02-28-2012 08:42 AM
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.
02-15-2012 12:51 AM
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.
02-14-2012 02:15 AM
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.