Switches - Stiga MPV 320W Workshop Manual

WORKSHOP MANUAL
MPV 320W / 520W
5. Make the final jumper cable connection to the engine block or the furthest ground point away
from the discharged battery.
WARNING!
ing the engine.
6. Start the engine. If the engine will not start after several tries, the machine or battery may need
servicing.
7. After the engine starts, leave the cables connected for one to two minutes.
8. Disconnect cables in reverse order.
9. Use the machine normally to charge the battery.

7.2.3 Switches

Switches either open a circuit to stop current flow or close and allow current to flow through.
• A normally open (NO) switch prevents current flow until the switch is actuated, completing the
circuit and allowing current to flow through it. An example is a light switch - the lights are off until
the switch is actuated and the lights go on.
• A normally closed (NC) switch allows current to flow until the switch is actuated, breaking the cir-
cuit and stopping current flow through it. An example is an ignition switch that grounds the mag-
neto when in the OFF position (completing the circuit) but opens the circuit when in the ON po-
sition allowing the engine to operate. The switches are selected with reference to their nominal
current (the contacts must be of sufficient size to carry the required current), rated voltage and
type of actuation (pressure switches, traction, rotation, momentary contact or microswitches).
NOTE - Check that the connections to the switches are stable and that the switch is actuated
correctly before performing an electrical test (Safety switches may need adjusting in order to be
actuated correctly).
IMPORTANT - During the check process, remove the switches from their respective circuit, un-
plugging the connector. If the cables are left in place, the machine components or the meter may
be damaged.
a) Normally open switch (NO)
To test a normally closed switch connect the ohmmeter between the switch
terminals.
• The meter should indicate an open circuit (infinite resistance «∞»).
• Activate the switch. The Ohmmeter should indicate a closed circuit (zero
resistance «0»).
This indicates the switch is operating properly. Variation from test results de-
scribed indicates a defective switch.
- Make sure the cables are clear of any moving engine parts before start-
Chapter
7 - ELECTRICAL SYSTEM
EDITION PAGE
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