PRODUCT IMPROVEMENT PROGRAM FOR REMOVING AIR SHUTOFF SYSTEM FROM CERTAIN 3508B, 3512B, AND 3516B ENGINES Caterpillar

PROBLEM

AFFECTED PRODUCT

PARTS NEEDED

ACTION REQUIRED

OWNER NOTIFICATION

SERVICE CLAIM ALLOWANCES

PARTS DISPOSITION

MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.

Attach. (1-Owner Notification)
        (2-Rework Procedure)

COPY OF OWNER NOTIFICATION FOR U.S. AND CANADIAN OWNERS

SAFETY - PRODUCT IMPROVEMENT PROGRAM FOR REMOVING AIR SHUTOFF SYSTEM

MODELS INVOLVED - CERTAIN 3508B, 3512B, AND 3516B ENGINES

Dear Caterpillar Product Owner:

New electronic overspeed protection device needs to be installed on the products listed below. Air shutoff valves on 3500B engines have experienced inadvertent closure or failure to close when required. Operating the engine with one air shutoff valve in the closed position may result in damage to the turbocharger and/or the air cleaner catching fire. All 3500B engines utilize the Engine Control Module (ECM) to monitor engine speed. In the event of an engine overspeed the ECM disables power to the electronic fuel injectors stopping the engine. With the removal of the air shutoff devices, Caterpillar will install a redundant electronic overspeed protection solution. This electronic overspeed protection solution contains no moving parts resulting in enhanced reliability and durability. In the event of an engine overspeed the newly installed electronic overspeed protection solution will provide redundant capability to interrupt all battery power to the ECM resulting in engine shutdown.

Contact your Caterpillar dealer if your engine operates in a combustible environment or regulations specifically require air shutoffs and new air shutoff devices will be installed. The dealer will advise you of the time required to complete this service. Please refer the dealer to their Service Letter dated March 1, 2004 when scheduling this service.

We regret the inconvenience this may cause you, but urge you to have this service performed for your added safety and satisfaction.

Identification #(s)

Attached March 1, 2004 Service Letter

Procedure for Redundant Electronic Over speed Protection?Field Rework

2348721 box operation; The 2348721 box is equipped with a two position switch labeled "OFF/RESET" and "ON". With the switch in the "ON" position the 2348721 box is activated and provides redundant over speed protection. In the "ON" position the green lamp labeled "SPEED SWITCH POWER" will be lit. In the event of an engine over speed shutdown triggered by the 2348721 box the red lamp labeled "ENGINE OVERSPEED" will be lit. After troubleshooting and correcting the cause for the over speed, the selector switch needs be momentarily placed in the "OFF/RESET" position. Placing the two-position switch in the "OFF/RESET" position resets the speed switch contained in the box. The circuit breaker can be placed in the off position allowing the operator to disable the 234-8721 box in the event of a component failure. In the off position the 234-8721 box is deactivated allowing the engine to operate without the redundant over speed protection system (engine will continue to be protected by the ECM). Pressing in on the respective lamps can check the light bulbs in both the red and green lamps.

Installation Instructions

1. Mount 2348721 box either to the side of the engine on the cylinder head rocker box or to an alternate location off of the engine. Location of the box should be such that the magnetic pickup harness will reach the flywheel housing and the six wire ECM harness will reach the engine ECM.
2. Disconnect or disable the 24V power source to the engine.
3. Remove the "C-Key" plug assembly from the engine ECM. See Illustration 1.




Illustration 1

 

4. From the "C-Key" plug, locate and remove the wires at pin locations 4 and 6 (Battery +, 150-RD-14) also remove the wire from pin location 5 (Battery -, 229-BK-14). Refer to Illustration 1.
5. Using the six wire harness supplied with the 2348721 box, insert the thee wires that were removed from the ECM "C-Key" plug into the six pin deutsch connector utilizing Table 1. Note wires need to be routed under the rubber boot as shown in Illustration 2.




6. Place the three wires from the 6 pin deutsch connector into the ECM "C-Key" plug utilizing Table 2.

7. Remove one of the plugs from the top of the flywheel housing, (as shown in Illustration 3) insert the magnetic pickup supplied with the 2375334 harness as. until it contacts the flywheel ring gear, then turn magnetic pickup out 1/2 turn and lock down jam nut.

 

 
 




Illustration 3

8. Using 7K1181 plastic ties, secure both harnesses to the engine harness, coil any excess harness and secure.
9. Referencing illustration 4 loosen the adjusting wheel lock screw on the speed switch located in the 2348721 box.
10. With engine stopped, turn speed switch adjusting wheel up to 100.
11. Using table 3 find your engine high idle and the "85% verify speed" EXAMPLE: An 1800 rpm engine would have a 85% overspeed verify RPM of 1805 rpm.
12. To adjust the speed switch, closely follow the steps below.
10. Operate the engine at the 85% verify rpm, using table 3.
11. Depress the "85% overspeed verify activation button", while holding this button in, slowly turn the "speed switch adjusting wheel" toward the lower numbers. The engine should shutdown.
12. Cycle the switch on the 2348721 box to the "off/reset" position and then back to the "On" position.
13. Restart engine.
14. With engine restarted, depress the "85% overspeed verify activation button" and slowly elevate the engine rpm.

1. Engines operate in a combustible environment i.e. well service or drill rig application.
2. Air shutoff valves are specifically required by a sanctioning society.

When hydraulically actuated air shutoffs are required please order the following parts for engines listed in GROUP 4.
 
 
 
 

1. Find the 40 pin "Customer connector" on the engine being serviced.
2. Remove the two jumper wires from pins 33, 34, 20 and 21.
3. From the 2110194 switch harness, insert wire labeled "Shutdown C IN" into the 40 pin connector at location #33.
4. From the 2110194 switch harness, insert wire labeled "Shutdown D IN" into the 40 pin connector at location #34.
5. From the 2110194 switch harness, insert wire labeled "Shutdown C OUT" into the 40 pin connector at location #20.
6. From the 2110194 switch harness, insert wire labeled "Shutdown D OUT" into the 40 pin connector at location #21.

AIR SHUTOFF SWITCH TESTING PROCEDURE

1. With both air shutoff valves latched in the open position and both switches connected, turn engine control panel power ON (both valves should remain open, if they did not check your switch wiring.
2. With engine control panel power ON activated the emergency stop button, both air shutoff valves should close. If both air shutoff valves did not close, check the switch wiring and the solenoid wiring. If both air shutoff valves closed proceed to step 3.
3. Turn engine control panel power OFF and reset the emergency stop button top the run position. Relatch the right hand air shutoff valve ONLY to the open position, turn engine control panel power ON (the right hand air shutoff valve should close). If the right hand air shutoff valve closed proceed to step 4. If right hand air shutoff valve did NOT close, check the switch and wiring on the right hand air shutoff valve.
4. Turn engine control panel power OFF and relatch the left hand air shutoff valve ONLY to the open position. Turn engine control panel power ON, the left-hand air shutoff valve should close. If the left-hand air shutoff valve closed proceed to step 5. If left-hand air shutoff valve did NOT close, check the switch and wiring on the left hand air shutoff valve.
5. Testing is only complete when engine successfully passes steps 1-4.

AIR SHUTOFF SWITCH TESTING PROCEDURE

1. Manually trip one air shutoff valve, this should cause an emergency stop condition and the remaining air shutoff valve should close.
2. If the engine experienced an emergency stop condition but the remaining valve did not close, bleed the air from the line going to the air shutoff hydraulic cylinder.
3. If the engine did not initiate an emergency stop condition the switches are not correctly wired into the emergency stop circuit.


NOTE: Both switches should be in a closed state (show continuity) when the air shutoffs are latched in the open position. After the wiring issue has been resolved repeat step 1.

4. Close one air shutoff valve and attempt to start the engine. If engine cranks but will not start the switches are performing correctly (ET will also show an active emergency stop condition). Proceed to step 6.
5. If engine starts with one air shutoff closed, check the switch on the valve that is closed (switch should not have continuity). If the switch has continuity remove the switch and inspect. If the switch doesn?t show continuity further troubleshoot the switch wiring.
6. With both air shutoff valves in the open position, activate the emergency stop, both air shutoff valves should close. If both valves closed testing is complete, if only one air shutoff closed bleed air from the line at the cylinder that failed to close and repeat step 6.