The starter/generator control module (SGCM) cooling system description and operation
is divided into three areas:
• | SGCM Cooling System Components |
• | SGCM Cooling System Operation |
• | SGCM Cooling System Coolant Cycle |
SGCM Cooling System Components
SGCM
The starter/generator control module (SGCM) is a GMLAN device. The SGCM monitors
3 coolant temperature sensors that are mounted in the coolant stream, 4 coolant level
sensors that are mounted in the electronics coolant of the SGCM, the SGCM coolant
pump relay control circuit, and the SGCM coolant fan relay control circuit to maintain
its internal cooling requirements. Internal to the SGCM are the electronics that control
the system voltage, these electronic components are immersed in a coolant. This coolant
is not the coolant that is circulated though the coolant circuit, the coolant helps
evenly distribute the heat of the electronics and are monitored by the 4 coolant level
sensors.
SGCM Coolant Pump
The SGCM coolant pump is controlled through a relay by the SGCM. The SGCM coolant
pump circulates the coolant through the SGCM cooling system.
SGCM Coolant Fan
The SGCM coolant fan is controlled through a solid state relay by the SGCM.
The SGCM coolant fan is a puller type fan that draws air through the SGCM radiator.
SGCM Cooling System Operation
The purpose of the starter/generator control module (SGCM) coolant system is
to cool the SGCM internal electronics. The SGCM commands the SGCM the SGCM coolant
pump and coolant fan ON or OFF at the following temperatures:
• | Coolant pump from OFF to ON at 60°C (140°F) |
• | Coolant pump from ON to OFF at 55°C (131°F) |
• | Coolant fan from OFF to low speed at 75°C (167°F) |
• | Coolant fan from low speed to high speed at 80°C (176°F) |
• | Coolant fan from high speed to low speed at 75°C (167°F) |
• | Coolant fan from low speed to OFF at 70°C (158°F) |
SGCM Cooling System Coolant Cycle
The starter/generator control module (SGCM) coolant is a 50/50 mixture of DEX-COOL
antifreeze and clean, drinkable water. The coolant is drawn from the SGCM coolant
tank by the SGCM coolant pump. The coolant pump then forces the coolant through the
SGCM coolant radiator. The coolant then is sent to the SGCM to cool the SGCM electronics.