SEAL-O-RING 8U5372 - Caterpillar

Unburned gas in the air inlet and exhaust system may ignite when the engine is started. Personal injury and/or property damage may result.Before starting an engine that may contain unburned gas, purge the unburned gas from the air inlet and exhaust system. Refer to the topic on purging unburned gas in the "Starting the Engine" section.
Become familiar with the following information:
Types of the alarm and shutoff controls
Locations of the alarm and shutoff controls
Conditions which cause each control to function
Resetting procedure that is required before starting the engineOn CG137-12 Engines, protective devices are available for the following conditions:
Low oil pressure
High coolant temperature
Overspeed
Low coolant levelFurther protection is supplied by an emergency stop button.Three basic protection systems are available:
Self-powered shutoff
Automatic start/stop system
Customer supplied shutoffNote: For an energize-to-shutoff system, the gas shutoff valve must be energized to shut off gas to the engine. For an energize-to-run system, the gas shutoff valve must be energized in order to supply gas to the engine.Power for the self-powered system is supplied by the magneto. The self-powered system can be used with an air starting motor or an electric starting motor. An energize-to-shutoff gas valve and an instrument panel are required for this system.Power for the automatic start/stop system is supplied by an external 24 V electrical source. The automatic start/stop system can be used with an air starting motor or an electric starting motor. An energize-to-run gas valve and one of these controls are required:
Automatic start/stop switchgear
Engine Control LogicFor the customer supplied shutoff system, the customer must supply all of the wiring and the shutoffs. The customer supplied shutoffs and wiring includes the emergency stop button and wiring.The features of the shutoff systems are listed in Table 1.
Table 1
CG137-12 Engine Protective Systems
Item Type of System
Self-Powered Automatic Start/Stop Customer Supplied (1)
High coolant temperature Yes Yes Yes
Low oil pressure Yes Yes Yes
Overspeed No (2) Yes Yes
High inlet manifold air temperature No No Yes (3)
High aftercooler water temperature No No Yes (3)
Emergency stop Yes Yes Yes
(1) The customer is responsible for supplying the shutoffs and the wiring.
(2) Overspeed protection is available as an option.
(3) The customer is responsible for supplying the protection for either high inlet manifold temperature or high aftercooler water temperature.Sensing Devices
The sensing devices that are described in this section are typical. The devices may be in different locations for different applications. Also, different applications may have different devices.Engines that use different generator set control panels will have different sensing devices.Overspeed
Speed sensor helps to monitor the engine rpm. The speed sensor senses the motion of the flywheel ring gear. The speed sensor is used with a tachometer in order to display the engine rpm.The speed sensor can also be used with an electrical overspeed switch. The overspeed switch is mounted in the junction box. The recommended setpoint is 110 percent of the rated rpm. If an overspeed occurs, the "RESET" button on the switch must be reset before the engine can be started.The switch also has a "VERIFY" button. The button enables the operation of the switch to be