Husqvarna K6500 Ring Workshop Manual page 34

15
Throttle, passive
2a
5 4 3
5–4: <20 kΩ
4–3: approx. 220 kΩ ± 20
∞
2a–2 ↓:
Ω
Insulation testing 1,000 volts
Measure against phase pins K, A and B
and earth point
Earth continuity testing
Measure against earth pin C
and earth point
34
TROUBLESHOOTING
Throttle, active
2 2a
5 4 3
5–4: approx. 220 kΩ ± 20
4–3: approx. 0 Ω
2a–2 ↓: approx. 0 Ω
Signal cables, connection testing and insulation testing
This test is used to check whether any cable is broken and whether
there is any damaged insulation which is causing the wires to come
into contact with one another.
This test is carried out with a multimeter set for connection
testing with a buzzer signal. The cabling does not need to be remo-
ved from the machine for this test.
Test methodically. The easiest way to proceed is to start from the
rectangular connector. Place the first test pin in any terminal. Use
the second test pin to test against all pins in the round contact. If
the cabling is intact, there must be a connection with one of the
pins, but not with any of the others. Proceed using the same
method to test the other cables. Note that there are pins with no
cable connections: see the wiring diagram on page 27.
There is very little likelihood of any of the signal cables coming
into contact with the motor cables due to damaged insulation, but
this can be tested by also including the motor's connector in the
test.
Switch
The cable connectors and removal of the switch from the control
2
unit are described on Pages 26 and 27.
Switch functions can be checked using a multimeter set for
resistance measurement. Check the resistance values across the
terminals, numbered as illustrated, in passive and active modes.
The values are typical for a functional switch.
Display card
If the HF unit and cabling are complete, the cutting machine's
display must be shown. If the information "UNKNOWN UNIT"
is displayed, the display unit is defective. If this is the case, replace
it.
Note: even if the display shows communication between the
cutting machine and the HF unit, this is not proof that the cabling
between the two is fault-free.
Insulation and earth continuity testing
IMPORTANT
Legislation on insulation and earth continuity testing
differs from country to country. Hence it is impor-
tant to find out about applicable regulations in the
country in which the service is carried out.
These safety tests are the last things done when the service actions
have been completed and the machine has been reassembled.
Insulation testing
Measure with 1,000 volts between an earthed metallic part which
can be touched and the phases (K, A and B) of the contact. There
must be no current flowing between earth and the phases (max.
ohm value).
Earth continuity testing
Earth continuity testing shows that the machine's earthing is fault-
free. Set the instrument for continuity measurement. Current must
flow between an earthed metallic part which can be touched and
the earth pin C of the contact (min. ohm value).