ELECTRICAL SYSTEM
109
•
Heat and Vibration:
Heat and vibration are
hard on most mechanical devices. The same is
true of electronics.
•
Moisture:
Moisture causes a nasty combination
of corrosion and shorts. Corroded connections
and wires create resistance that results in low
voltage and ground issue. Many electronic com-
ponents are “potted” or encased in a sealant that
protects them from moisture. They are still vul-
nerable to bad inputs caused by corroded exter-
nal connections and damaged switches.
•
Improper Tools:
Some test lights can over-
load electronic circuits.
Electrical environment: AC Vs. DC
Most modern outdoor power equipment that has an
electrical system complex enough to require diagnosis
will be equipped with an alternator that produces alter-
nating current (AC). In most systems, this current is
immediately rectified to direct current (DC), and regu-
lated to a nominal 12 Volts. The presence of AC is very
limited. The primary concern of this section is 12 Volt
DC systems, though much of the theory and tech-
niques apply equally well to other DC systems.
1.
Voltage:
Pressure
•
Voltage is the “pressure” that electricity has. It is
the amount of force pushing electrons through a
circuit.
•
The unit of measurement for this pressure is
volts.
•
The capital letter “V” is used to represent volts.
•
Most (not all) outdoor power equipment operates
on a nominal 12 volts. In practice, system volt-
age may run as high as 13.5V or 14V.
2.
Amperes:
Flow
•
Current is the “flow” of electricity. It is the amount
of electrons flowing in circuit.
•
The flow of current is measured in Amperes or
Amps for short.
•
The capital letter “I” is used to represent Amps.
3.
Ohms:
Resistance
•
Resistance is the opposition to current flow. It is
a restriction that slows down the flow of current.
•
Resistance is measured in Ohm’s.
•
The greek letter omega “
Ω
”,
or the letter ”R” for
Resistance
is used to represent Ohm’s.
•
Resistance creates heat. A circuit with too much
electrical load, or too much resistance for the
load placed on it will get hot.
Summary of Contents for 900 series
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Page 6: ......
Page 12: ...ENGINE RELATED PARTS 6 ...
Page 62: ...HYDRO DRIVE AND BRAKE SYSTEM 56 ...
Page 98: ...CVT Drive and brake system 92 ...
Page 135: ...ELECTRICAL SYSTEM 129 Schematics LECTRIC 04 ...
Page 136: ...ELECTRICAL SYSTEM 130 ANUAL 04 ...
Page 152: ...Cutting Decks And Lift Shaft 146 ...
Page 158: ...APPENDIX 152 ...
Page 165: ...310 0510 IHT 5 MODEL RECOGNITION 618 0319 166768 104 1760 173839 036932 618 0389A ...
Page 190: ...310 0510 IHT 30 310 0710 EXPLODED VIEW ...
Page 192: ...310 0510 IHT 32 310 0610 EXPLODED VIEW ...
Page 194: ...310 0510 IHT 34 310 0510 EXPLODED VIEW 6 SEALANT 57 20W 50 OIL 127 SEAL O RING KIT ...
Page 198: ...310 0510 IHT 38 2008 HYDRO GEAR Printed in U S A Rev P1 ...