New Holland CX720 Repair Manual page 2311

Cold start aid - Static description (B.80.A.30 - C.30.A.20)
CX720, CX740, CX760, CX780, CX820, CX840
The engine cold start aid-(grid heater), where fitted is located in the inlet manifold and assists engine start up under
cold climatic conditions. It increases the inlet air temperature so that the compressed air temperature is high enough
for definate combustion of the injected fuel.
The grid heater consists of a metallic heater element with relays so that heating can be controlled in 4 phases. The
engine electronic control unit manages this function and the driver is informed on the status of the grid heater by the
preheat lamp located below the ignition switch.
Phase 1. Temperature reading.
When the ignition key is turned on the temperature of the air, fuel and coolant are taken and the lowest of these is
taken as the controlling value.
Phase 2. Pre-Heating
If the lowest of these values is below 30 °C (86 °F) and the battery voltage is between 11-14 volts the preheating
phase will commence. The duration of this preheat phase is a maximum of 15 seconds but is determined by the
battery voltage.
Phase 3. Cranking
During this period the heater remains on for a period of 15 seconds. If engine has not started after this period the
heater will turn off for 5 seconds and then turn back on for a period of 10 seconds.
Phase 4. Post Heating
Once the engine has started the heater will remain on for a maximum period of 5 minutes as monitored by the engine
electronic control unit.
If however the battery voltage falls below 11 volts during this period the heater will be turned off.
POWER PRODUCTION - STARTING SYSTEM
BSD1875A
BSD1854A
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B.80.A / 3
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