Diagnostic Instruction; Electrostatic Discharges - Bernina arista 165 Service Manual

Diagnostic instructions
Warning: Dangerous voltage levels !
Mains voltage (refer to L-print page 27)
The switch part of the L-print and mains cable carry
dangerous voltages.
For your own safety do not touch the L-print until about
30 seconds after the main voltage has been switched off.
This is the time required for the capacitors to discharge.
Warning !
The sewing machine may only be connected to the mains
supply when the L-print cover is mounted.
Work may only be carried out on the L-print and mains
cable when the mains plug has been withdrawn from the
mains supply.
Protection of electrical components against electrostatic discharges
If two insulation materials (e.g. shoe sole and floor) rub
together there can be a build-up of static electricity.
Should this be discharged through electronic components
these can be seriously damaged.
One of the most effective measures to conduct these char-
ges away is earthing.
1. A bench suitable for working with components in today's
electronic industry has a surface that does not allow the
build-up of static electricity.
On the one hand the surface should be conductive so
that charges are conducted away but on the other hand
it should have enough resistance to prevent short-
circuiting and earthing of parts laid out on the bench.
2. By wearing a wristband that is connected to the bench
surface, static electricity can be conducted away from
the person. For safety reasons a resistance of approx.
1 M ohm has to be connected in series with the conduc -
tive wristband.
3. Electronic parts may only be dispatched in their original
packaging.
Refer to safety instuctions on page 1!
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