53
Technical data
and start-up
NLG5 charger
7.3
Pre-charging Voltage
INFORMATION
The following operating principle applies to the BRUSA battery type EVB1:
To avoid sparks when switching on, the connected loads are pre-charged with a 50 ohm PTC.
For this process, three independent voltage measurements are used.
The switching on of the battery (switching of the main contactors during pre-charging) is very
easily heard and can therefore be used as a monitor.
The pre-charging resistor is heated up by a succession of repeated (3-4 times) periods of pre-
charging. If overheating occurs then further pre-charging is temporarily not possible. In this case,
the pre-charging resistor must be cooled down over a particular period of time.
1.
Pre-charging contactor (1) closes.
U1 must be at the same level as the sum of the cells (U
batt
). There must be no current flowing.
2.
Main contactor (3) closes.
U2 must rise to the same level as U1 within 5 s. Current < = 4 A.
If the level is not reached, the CAN signal
BMS_Err_PreCharge
is emitted!
3.
Main contactor (2) closes.
4.
Pre-charging contactor (1) opens.
