TM 9-6115-668-13
1.14.1.3 Time t approximately 2.8 minutes.
K106 energizes and disconnects the coil of K103 from +24 V. K103 deenergizes.
If burner monitor temperature switch S109 is open, i.e. K104 is not excited, the heating system must be restarted.
1.14.1.4 Time t approximately 3 minutes.
Time relay K110 energizes:
N-C contact 15-16 is open, disconnecting the coil of K101 from +24 V. K101 deenergizes. The combustion
chamber is no longer preheated, and N1 is no longer heated.
+24 V is applied through N-O contact 15-18 to the coil of K102. Auxiliary contactor K102 energizes and
switches +24 V, through N-O contact 30-87, to the oil pump motor (2M3).
If burner monitor temperature switch S109 is closed, K109 remains excited. Engine oil is pumped through
the air-oil-heat exchanger and heated. Residual heat from the preheating assembly is blown through the air
flap and a hose onto the fuel injection pump, cylinder heads, and generator belts. This status is maintained
for a timed period.
If temperature switch S109 is open, K109 deenergizes and H101 goes out. The heating system must be restarted.
1.14.1.5 Time t approximately 13 minutes.
Time relay K108 energizes:
N-C contact 25-26 is open, disconnecting the air flap puller magnet from +24 V. The air flap closes. This
prevents the engine EHG from forcing cold air into the heating system.
The READY TO START IF HEATING IS ON indicator light (H102) is connected to +Vreg through N-O contact
15-18, and lights up. The diesel engine can be started.
If the diesel engine is started before the READY TO START IF HEATING IS ON lamp lights up, the air flap puller
magnet is disconnected from +24 V by the open N-C contact 21-22 of K6, and the air flap closes (see above).
1.14.1.6 Starting Up, the Engine Preheating Assembly at Temperatures above 14 °F (-10 °C).
If the engine preheating assembly is started up at a temperature above 14 °F (-10 °C), one of the two temperature
switches S103/S104 is open. As a result, K109 does not latch, i.e. the heating system shuts down again within one
minute (paragraph 1.14.1.1).
1.14.1.7 Shutting Down the Engine Preheating Assembly.
Normal Operation
When the engine oil has reached a temperature of approximately 140 °F (60 °C) either temperature switch S103
(60-degree, 3%) or S104 (63-degree, 6%) opens, and shuts down the heating system.
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