Electrical Circuit Diagram - Husqvarna 967187001 Workshop Manual

Drive motor
+36V from key switch

12.5 Electrical Circuit Diagram

The key switch is always supplied with +36 V
from the batteries via a 5 A fuse. When the key is
turned to the on position, R2 will be activated and
energized, and the gray lead, pin 7, is coupled to
the brown lead, pin 6 via the relay while CCU is
supplied with power. When the driver presses the
activation switch (I), the CCU output (Main Re-
lay) couples the brown lead to GND (shown with
switch function to GND in figure) to activate relay
RE1. The motor control electronics sends +36 V
via Main Relay output A10 (brown lead from drive
motor). This voltage arrives about 500 ms after
the motor has received power via the key, which
energizes RE1 and the machine is activated. Both
D1
DIODE
SW_KEY
KEY
FU
5A
+36V
GND
Key switch to CCU
Key switch to motor
36+V from motor
500mS after key switch on
GND
these relays have a freewheeling diode across its
coil (D1 and D2 in figure below), the CCU unit is
able to handle relay without freewheeling diode but
not the electronics inside the drive motor. These
diodes are therefore very important, and if they dis-
appear of their leads break, the drive motor elec-
tronics will be damaged. Inside CCU are a number
of functions so that a fault on the output driving the
relay can be seen. The output is short-circuit proof
and CCU can detect if the output is short circuited.
The output can also indicate a break in the lead
out to the relay, so that CCU can send a fault indi-
cation to CST. This is so that the test can show if
there is a fault, break or short circuit.
CCU
CCU +36V IN
MAIN RELAY
CCT001
MAIN RELAY
3
RE2
POWER RELAY
ALTERNATING
GND via CCU
Alternating power relay
Free wheeling diodes
Main relay
START
START_SW
ACTIVATE
+5V OUT
DRIVE MOTOR
D1
BATT+
D2
RE1 BATT-
A1
Speed feedback
4
A2
Speed IN 0-4,5V
A3
Error out
A4
Temp sensor
A5
Enable input
A6
Forward/Backwa
A7
D2
Dynamic Brake
A8
NC
A9
0V REF
A10
DIODE Main contactor
A11
Key switch
A12
Analog 0V REF
CST-drive mode logging
Connector at CCU
C7: Main relay on/off
M
117
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