Under-Voltage And Over-Voltage Protection - Sevcon MillipaK 4QPM Manual

Controller Protection
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Under-voltage and over-voltage protection

In order to prevent a sudden loss in power, the controller will begin to linearly ramp down the
current limit, once the average battery voltage falls below a pre-set under-voltage start level. The
current will be ramped down to 0 and a 7 flash fault indicated if the averaged battery voltage falls
below the under-voltage cut-out level.
To protect the controller from over-voltage caused by prolonged regen braking, regen braking will
be reduced when the average battery voltage reaches the over-voltage start level. If the voltage
exceeds the over-voltage cut-out level in braking then the line contactors will open and
freewheeling will occur, requiring the vehicles foundation brakes to be used.
Under any other circumstances if the battery voltage exceeds the over-voltage cut-out level, all
pulsing is stopped and a 7-flash fault is indicated. This protects against incorrect battery
connection.
Nominal
Battery
Voltage
24 V
36 V
48 V
Table 8: Under and Over-Voltage Cutback Levels
The following calibrator menu items are used to set these values.
Low Voltage Start
Calibrator Menu Reference:
Minimum Maximum
Low V System
Cutout Voltage
Low Voltage Cutout
Calibrator Menu Reference:
Minimum Maximum
14.5V Low V Start 0.5V
High Voltage Start
Calibrator Menu Reference:
Minimum Maximum
System High V
Voltage Cutout
MillipaK 4QPM Controller Manual
Under-voltage
Cutout Voltage Start
(adjustable)
14.5V Under Voltage
Cut-out up to
14.5V
14.5V
Immediate
11.08
Step Size Typical Value
0.5V 18.0V
Immediate
11.09
Step Size Typical Value
16.0V
Immediate
11.10
Step Size Typical Value
0.5V High V Cutout
Under- Over-voltage
Start
(adjustable)
System V up to
Over Voltage
System V Cut-out
Page 60
Under/Over Voltage Protection
Over-voltage
Cut-out
30.0V
45.0V
57.0 V
13/08/03