JLG M4069 Service Manual - Manual (Page 45)

SECTION 3 - CHASSIS & SCISSOR ARMS
3121639 – JLG Lift – 3-13
Timing Sequences
NOTE: Throughout the Generator section, the abbreviations
RBS and CTS are used. RBS stands for Rotary Bat-
tery System, which is the generator system. CTS
stands for Call To Start, which is the electronic inputs
which signal the generator to start and charge the
batteries.
• RBS Pre start Sequence
1. Time Delay Engine Start (TDES)
TDES is the period which the RBS waits to verify that
the CTS is valid rather than a transient condition.
2. Time Delay Pre-Heat (TDPH)
TDPH, if enabled, occurs after TDES has elapsed
and the engine temperature is below the factory set
engine preheat temperature setting. The engine pre
heater will be energized for the factory set preheat
delay period.
• RBS Startup Sequence
1. Crank Time
The RBS will crank for a period up to the crank time
or until the engine starts.
2. Rest Time
If the engine does not successfully start, the RBS will
wait for the rest time before attempting to crank the
engine again.
3. Crank Cycles
The RBS will attempt to start the engine up until the
number of crank cycles is reached. If the RBS does
not start, an Overcrank fault is indicated.
4. Time Delay Bypass (TDBP)
Once the engine starts, TDBP must elapse before
low oil pressure and underspeed shutdowns are
activated. This allows the engine to come up to nor-
mal operating conditions before enabling these
shutdowns are monitored.
• RBS Shutdown Sequence
Once all CTS conditions have been removed, the RBS will
begin the shutdown sequence. If a CTS condition is initi-
ated during the shutdown sequence, the RBS will return to
normal running operation until the CTS is removed.
1. Time Delay Engine Run (TDER)
Once the CTS condition is removed, the TDER
period begins. This period ensures that no further
CTS conditions occur prior to the cool down period.
2. Time Delay Cool down (TDC)
Once the TDER period ends, the alternator output is
reduced to a minimal level in order to allow the
engine to cool down for the TDC period. If a CTS is
received during the TDC period, the CTS must last
for at least the TDES period for the RBS to return to
normal running operation.
Table 3-4. RBS Pre start Sequence
CTS (Call to Start)
TDES (Engine Start)
Preheat Delay
RBS Startup Sequence
Table 3-5. RBS Startup Sequence
Crank Time -> Rest Time
(Until Engine Start or # of Crank Cycles)
TDBP Bypass
Normal Running Operation
Table 3-6. RBS Shutdown Sequence
Remove CTS
TDER Engine Run
TDC Cool down
Engine Stop