SEAL-O-RING 1090074 - Caterpillar

Engine: 3508B (S/N: 2HW1-UP; 3DW1-UP) 3512B (S/N: 1PW1-UP; 4AW1-UP) 3516B DI EUI TA (S/N: 1NW1-UP; 2FW1-UP)Introduction
This modification is recommended for the following engines: 3508B land and offshore petroleum engines, 3512B land and offshore petroleum engines and 3516B land and offshore petroleum engines. These engines must be equipped with the electronic instrument panel. This modification can be applied only when there is an external 0 to 200 mA engine fuel control signal. These applications include SCR systems.Description and Function
The engine Electronic Control Module (ECM) normally uses a desired speed signal to set the steady engine speed. This system depends on the engine ECM in order to govern the engine at a steady engine speed. Direct fueling bypasses the governor in the engine ECM. In addition, direct fueling sends a signal directly to the injection portion of the engine ECM.This modification consists of a control signal filter and a current-to-PWM (Pulse Width Modulated) converter. The converter sends the PWM signal to the engine ECM. This modification allows SCR controlled systems to use an engine actuator signal of 0 to 200 mA. This signal is used to control a 3500B series engine. The modifications to the software within the engine ECM allow this control signal to directly control the virtual rack position of the engine. When the direct fuel control is enabled, the input control current from the SCR control is proportional to the desired fuel. The engine ECM retains basic engine protection functions.
Illustration 1 g00712782
Once the modification is installed, the capabilities of load sharing that are built into the SCR control can be fully utilized. With this modification, it is easy to repower a D399 engine with a 3500B series engine. This modification also makes it possible to parallel a 3500B series engine with a mechanical unit injected (MUI) engine.The following major components are added during this modification:
A resistive/inductive input filter
One control group that is used to convert the 0 to 200 mA signal to a PWM signal
Software that is flashed into the engine ECM which allows the direct fueling to function
Table 1
Software Part Numbers    
Model     Features     Part Number    
3508B     Direct Fueling, Land, 1200 RPM     185-2987    
3512B     Direct Fueling, Off-Shore, 1200 RPM     193-3284    
3512B     Direct Fueling, Land, 1200 RPM     193-3285    
3516B     Direct Fueling, Off-Shore, 1200 RPM     185-3019    
3516B     Direct Fueling, Land, 1200 RPM     185-3017    Glossary of Terms
Engine ECM - Electronic control module for 3500B series enginesECS (Engine Control Switch) - The switch is located on the electronic instrument panel. The switch is considered to be the master control for the engine.EIP (Electronic Instrument Panel) - The EIP contains the electrical connections that are used for the engine's instrumentation and the engine's controls. This panel is usually mounted on the 3500B series engine. In some applications, the EIP may be mounted in a remote location.Subpanel for the EIP - The subpanel is a steel plate that is mounted in the back interior