Hyundai Yanmar TNV Series Manual page 65

CONTROL SYSTEM
Starting aid
Using an optional air heater relay allows the starting aid (air heater or glow plug) to be controlled as follows.
The air heater relay permits the E-ECU to check for disconnection or short-circuit.
1. ON-glow control (standard feature)
When the key switch is moved to the "ON" position, the air heater relay is automatically energized for a
duration that depends on the coolant temperature. The preheat lamp can be on during energization.
(This feature is the same as provided by QHS controller 129457-77900. QGS controller 119650-77900
has a two-stage temperature control feature).
The preheat time for ON-glow control differs for an air heater and a glow plug used as the starting aid.
See Figure 2-35.
2. Simultaneous energization (standard feature)
This feature allows energizing the air heater relay while energizing the starter when the key switch is in
the START position, facilitating cold start. (This feature is the same as provided by QHS controller
129457-77900 and QGS controller 119650-77900).
When the voltage at the power supply terminal of the E-ECU decreases to 6.5 V, the air heater relay is
de-energized to prevent the E-ECU from being reset due to "supply voltage low" (the E-ECU is reset
when the supply voltage lowers to 6.0 V).
Energization of the air heater relay can be halted while the starter is energized.
3. After heating (optional feature)
This feature allows the air heater relay to be energized for 80 seconds after engine start or as long as
the coolant temperature is lower than 10°C, thereby reducing the time required for self-extinguishing of
blue and white smoke. (This feature is the same as provided by QHS controller 129457-77900 except
for temperature and time settings. QGS controller 119650-77900 has no after glow feature). Åj
The after heating feature is disabled by default to avoid a heavy burden on the battery. Use this feature
in due consideration to the battery charging/discharging cycle.
35
30
20
10
0
-30 -20 -10
a) Preheat time for air heater
2-46
1s
0 10 20 30 40
Coolant temperature [°C]
Figure 2-35 Preheat time for ON-glow control
35
30
20
10
0
50 -30 -20 -10
Coolant temperature [°C]
b) Preheat time for glow plug
TNV Application Manual
1s
0 10 20 30 40 50