JLG X20JP - X600AJ Service Manual - Manual (Page 149)

SECTION 3 - CHASSIS & TURNTABLE
3121623 – JLG Lift – 3-125
LEAD BATTERY
Lead Battery has to supply the power to switch on the
ECM1-2 and the BMS.
As soon as the BMS is active, the DC-DC is ON too, so the
power for the machine components is coming from the
lithium cells, not from the lead battery.
If the lead battery is completely down, the main board and
the BMS cannot be activated, so the machine cannot
start.
To avoid this situation, if the main key is on and the volt-
age level of the battery pack is less than 20%, the EMC1-2
will turn off all the system in case after one hour of no
movements activation.
Practically even if the operator forget the key switch in on
position, the lead battery will be preserved from complete
discharge.
ELECTRIC MOTOR
The electric motor installed is an AC three phases motor.
The choice of these specifics was made to grant the pos-
sibility to manage the revolutions without power torque
drops.
The double electric motor gear pump send hydraulic oil to
the valve blocks of the machine; the hydraulic diagram
respect the one of the standard (not lithium) platforms; the
only difference is that on the standard platforms there are
two motors installed: the engine and the electric motor.
On the lithium platform there is only the electric motor and
consequently only one hydraulic pump.
The Inverter controls directly the electric motor, changing
the revolutions according to the requests coming from the
ECM1-2 of the platform.
Manage the revolutions is very important, because it
allows to have both good performances and low level of
current consumption.
For example moving the tracks, the motor has to run as
fast as possible, while movements such as jib arm or bas-
ket rotation need less quantity of oil. Reducing the rpms
we can save energy and extend the working autonomy of
the pack.
The electric motor has a revolutions sensor and a temper-
ature sensor inside.
The revolution sensor informs the inverter about the real
rpms, consequently the inverter adjust them.
This speed sensor is important because the rpms are very
different in function of the load (for example moving one
arm, the necessary power depends on the position of the
arm itself).
Electric motor characteristics
48 Volt
Battery Pack
72 Volt
Battery Pack
Motor AC 3 phases AC 3 phases
Nominal
voltage 48 Volt 80 Volt
Power 2000 Watt 3500 Watt
M a x
RPM 2550 2550