12- 18
Service Manual
LWE130
© BT Europe AB
Electrical system – 5000
Functional description
T-code
Valid from serial number
Date
Order number
675
914369-
2005-09-23
226057-040
12.8.2 Transistor regulator
General
The ZAPI SEM-X transistor regulator drives the traction motor. It con-
trols the speed by varying the rotor voltage using pulse width modula-
tion (PWM). This also includes varying the “ON” time of the MOS tran-
sistors used to regulate rotor current.
Changing the truck’s travel direction is achieved by reversing the polar-
ity in the field winding (F1-F2). The regulator features a transistorised
four-quadrant bridge and a single-quadrant bridge for the rotor winding.
A status LED (Fig. 10 AL) displays eventual error conditions which may
be present.
Fig. 10 B shows the connector for the hand terminal.
NOTE!
In order to see the alarm status LED or gain access to the connector
for the hand terminal it is necessary to fold out the main electrical
panel. See section “12.4 Accessing main electrical panel” .
Safety
The regulator is a high-power component. When working on a battery
operated vehicle, necessary precautions should be taken. This
includes, but is not limited to, correct training, use of eye protectors,
avoiding use of lose-fitting clothes, removal of watches and jewellery,
and use of insulated tools only.
WARNING!
Risk of short-circuiting.
Remove all watches, jewellery and always use insulated tools only.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
A
1
2
3
4
5
6
7
8
B
ALARM
B
A
F1
F2
B-
VMN
B+
1
1
AL
Fig. 10 SEM-X transistor regulator
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