This document summarizes the cooling system of a C15 generator set engine. It has a pressure-type cooling system with a shunt line to prevent cavitation and allow the system to operate safely above the boiling point of water. A 30% ethylene glycol mixture is used as coolant. The system uses a water temperature regulator and radiator to maintain the proper operating temperature, circulating most of the coolant through an oil cooler first before returning it to the water pump.

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Producto: GENERATOR SET
Modelo: C15 GENERATOR SET C5L00217
Configuración: C15 Generator Set (50Hz) C5L00001­UP
Operación de Sistemas
C15 Petroleum Generator Set Engines
Número de medio ­SENR9928­07 Fecha de publicación ­01/04/2015 Fecha de actualización ­17/04/2015
i02404867
Cooling System
SMCS ­ 1350
This engine has a pressure type cooling system that is equipped with a shunt line.
A pressure type cooling system gives two advantages. First, the cooling system can be operated safely at
a temperature that is higher than the boiling point of water. Next, cavitation in the water pump is
prevented. It is more difficult for air or steam pockets to be made in the cooling system.
Note: Use a coolant mixture with a 30 percent ethylene glycol base in an Air­To­Air Aftercooler system.
The ethylene glycol base must be used for efficient water pump performance. This mixture keeps the
temperature range of the coolant high enough for efficient performance.

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Illustration 1 g01096647
Cooling system for a warm engine (Typical example)
(1) Cylinder head
(2) Water temperature regulator
(3) Outlet hose
(4) Vent line
(5) Vent tube
(6) Shunt line
(7) Elbow
(8) Water pump
(9) Cylinder block
(10) Oil cooler
(11) Inlet hose
(12) Radiator
In operation, the water pump (8) sends most of the coolant from the radiator (12) to the oil cooler (10) .

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The coolant from the oil cooler (10) goes into the cylinder block (9) through a bonnet and an elbow. The
coolant goes around the cylinder liners, through the water directors and into the cylinder head.
The water directors send the flow of coolant around the valves and the passages for exhaust gases in the
cylinder head. The coolant then goes to the front of the cylinder head. At this point, water temperature
regulator (2) controls the direction of coolant flow.
The water temperature regulator (2) is closed when the engine is cold. The coolant flows through the
regulator housing and elbow (7) back to water pump (8) .
If the coolant is at normal operating temperature, the water temperature regulator (2) opens and the
coolant flows to the radiator (12) through the outlet hose (3). The coolant becomes cooler as the coolant
moves through the radiator. When the coolant gets to the bottom of the radiator, the coolant goes through
the inlet hose (11) and into the water pump (8) .
Note: The water temperature regulator (2) is an important part of the cooling system. The water
temperature regulator (2) divides the coolant flow between the radiator (12) and the bypass elbow (7).
This will maintain the correct temperature. If the water temperature regulator is not installed in the
system, there is no mechanical control. Most of the coolant will go through the bypass. This will cause
the engine to overheat in hot weather. If a higher volume of coolant goes through the radiator, the engine
will not reach normal operating temperatures. This occurs during cold weather.
Shunt line (6) gives several advantages to the cooling system. The shunt line gives a positive coolant
pressure at the water pump inlet that prevents pump cavitation. A small flow of coolant constantly goes
through shunt line (6) to the inlet of water pump (8). This causes a small amount of coolant to move
constantly through the vent tube (5). The flow through the vent tube is small and the volume of the upper
compartment is large. Air in the coolant is removed as the coolant goes into the upper compartment.
The vent line is used to fill the cooling system with coolant for the first time. This will purge any air out
of the top of a bottom filled system.
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Mon May 09 2016 12:49:00 GMT­0500 (Hora est. Pacífico, Sudamérica)
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