ALTERNATORTri-CircuitTHE TRI-CIRCUIT ALTERNATORThe Tri-Circuit alternator consists of a single ring ofmagnets inside the flywheel, which supplies the magneticfield for a stator having one output lead which producesAC voltage. The output lead connects to a charge leadthat contains one diode which rectifies minus -12 voltsDC (5 amps at 3600 RPM) for lights. This same chargelead contains a second diode that rectifies plus +12 voltsDC (5 amps at 3600 RPM) for battery charging andexternal loads. See Fig. 205. The alternator uses lessthan 0.2 horsepower.Fig. 205 - Tri-Circuit AlternatorIf an accessory such as an electric clutch is used on theequipment, 3.5 amps powers the clutch, and up to 1.5amps charges the battery, thus not over-charging thebattery. A two-pole clutch switch is used on the vehiclewhen an electric clutch is an accessory. When the clutchis switched on, one circuit is used to engage the clutch,and the other circuit bypasses the resistor, thus allowingfull alternator output to be applied to the battery andclutch. Fig. 206 and 207.Fig. 206 - Typical Wiring DiagramFig. 207 - Typical Wiring Diagram (Cont’d.)If the clutch is not engaged, a resistor is placed in serieswith the alternator charge lead, thereby limiting thecharge current to about 3 amps. See Fig. 207. Theresistor (20 watts), becomes hot and must be mountedsomewhere on the vehicle by the manufacturer.The battery is not used for the lights, so lights areavailable even if the battery is disconnected or removed.Current for the lights is available as long as the engine isrunning. 12 volt lights with a total rating of 60 to 100watts may be used. With lights rated at 70 watts, thevoltage rises from 8 volts at 2400 RPM to 12 volts at3600 RPM, so the brightness of the light changes withthe engine speed.TESTING ALTERNATOR STATOR OUTPUTConnect load lamp to AC (green connector) output plugand ground as shown in Figure 208. Load lamp shouldlight to full brilliance at medium engine speed. If lampdoes not light, or is very dim at medium speeds, removeblower housing and flywheel. Disconnect the groundterminal end of AC coil, which is attached to the statorlaminations with screw.Fig. 208 - Testing Stator Output64
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
