INDICATOR (heat) 4K8515 - Caterpillar

Introduction
The Energize To Run (ETR) electric protection system offers full engine system protection (OP, WT, OS).The ETR type protection system requires that the gas shutoff valve (GSOV) must first be activated (and must remain activated) before fuel is allowed to the engine cylinders. After the engine starts to run, a problem with any of the engine systems that are monitored will cause the gas shutoff valve to be deactivated. This will immediately stop fuel to the cylinders and cause engine shutdown.The full protection system arrangement monitors the engine from starting through 118% of rated speed.Component Description
Electronic Speed Switch (ESS)
7W2743 Electronic Speed Switch (ESS)
(1) Verify button. (2) Reset button. (3) "LED" overspeed light. (4) Seal screw plug (overspeed). (5) Seal screw plug (crank terminate). (6) Seal screw plug (oil step).The Electronic Speed Switch (ESS) is designed with controls built into a single unit to monitor several functions at the same time. The functions that the ESS monitors are:Engine Overspeed (OS)
This is an adjustable engine speed setting (normally 118% of rated speed) that prevents engine from running at a speed that could cause damage to the engine. This condition will cause a switch to close that shuts off the fuel to the engine.Crank Termination (CT)
This is an adjustable engine speed setting that signals the starter motor that the engine is firing and cranking must be terminated. When the speed setting is reached, a switch will open to stop current flow to the starter motor circuit. The starter motor pinion gear will now disengage from the engine flywheel ring gear.Oil Step Latch
This feature of the ESS is not adjustable. After terminal ESS-17 has been energized by loss of engine oil pressure, the oil step switch (OPSS) contacts are now held in the closed position. This will maintain OPSS in a closed position until 2 seconds after the engine has completely stopped. This action will prevent the shutoff from resetting below oil step speed.Engine Oil Step Pressure
This is an adjustable engine speed setting that gives protection to the engine from a failure caused by too little oil pressure for a specified speed range. To maintain desired protection through the complete speed range of operation, two different oil pressure switches are used. One with a high pressure rating (OPS2), and one with a low pressure rating (OPS1).Once the oil step pressure speed setting is made, an engine that runs above this speed setting must maintain an oil pressure that is more than the higher oil pressure switch (OPS2) rating if oil step latch is used.An engine that runs below this speed setting must maintain an oil pressure that is more than the lower oil pressure switch (OPS1) rating. If either condition is not correct, a switch will close to activate an alarm or cause the fuel to be stopped to the engine.Magnetic Pickup (MPU)
Magnetic Pickup
(1) Clearance dimension. (2) Magnetic pickup. (3) Wires. (4) Locknut. (5) Gear tooth. (6) Housing.The magnetic pickup is a single pole, permanent magnet generator made of wire coils around