Guardian 4702, Repair Manual

Page: 3 / 92

T Ta ab blle e o off C Co on ntte en ntts s
Page 1
S SA AF FE ET TY Y ........................................................ IIN NS SIID DE E F FR RO ON NT T C CO OV VE ER R
S SE EC CT TIIO ON N 1 1::
G GE EN NE ER RA AT TO OR R F FU UN ND DA AM ME EN NT TA AL LS S ............................................ 3 3--7 7
MAGNETISM ................................................................ 3
ELECTROMAGNETIC FIELDS .................................... 3
ELECTROMAGNETIC INDUCTION .............................. 3
A SIMPLE AC GENERATOR ........................................ 4
A MORE SOPHISTICATED AC GENERATOR ............ 4
FIELD BOOST .............................................................. 6
GENERATOR AC CONNECTION SYSTEM ................ 6
S SE EC CT TIIO ON N 2 2::
M MA AJ JO OR R G GE EN NE ER RA AT TO OR R C CO OM MP PO ON NE EN NT TS S ........................ 8 8--1 11 1
ROTOR ASSEMBLY ...................................................... 8
STATOR ASSEMBLY .................................................... 8
BRUSH HOLDER .......................................................... 9
BATTERY CHARGE COMPONENTS .......................... 9
EXCITATION CIRCUIT COMPONENTS ...................... 9
CRANKCASE BREATHER .......................................... 10
S SE EC CT TIIO ON N 3 3::
IIN NS SU UL LA AT TIIO ON N R RE ES SIIS ST TA AN NC CE E T TE ES ST TS S ............................ 1 12 2--1 14 4
EFFECTS OF DIRT AND MOISTURE ........................ 12
INSULATION RESISTANCE TESTERS ...................... 12
DRYING THE GENERATOR ...................................... 12
CLEANING THE GENERATOR .................................. 12
STATOR INSULATION RESISTANCE ........................ 13
TESTING ROTOR INSULATION ................................ 14
THE MEGOHMMETER .............................................. 14
S SE EC CT TIIO ON N 4 4::
M ME EA AS SU UR RIIN NG G E EL LE EC CT TR RIIC CIIT TY Y .................................................... 1 15 5--1 17 7
METERS ...................................................................... 15
THE VOM .................................................................... 15
MEASURING AC VOLTAGE ...................................... 15
MEASURING DC VOLTAGE ...................................... 15
MEASURING AC FREQUENCY ................................ 16
MEASURING CURRENT ............................................ 16
MEASURING RESISTANCE ...................................... 16
ELECTRICAL UNITS .................................................. 17
OHM’S LAW ................................................................ 17
S SE EC CT TIIO ON N 5 5::
E EN NG GIIN NE E D DC C C CO ON NT TR RO OL L S SY YS ST TE EM M ................................ 1 18 8--2 26 6
INTRODUCTION ........................................................ 18
OPERATIONAL ANALYSIS .................................. 18-23
ENGINE CONTROLLER CIRCUIT BOARD ................ 24
BATTERY .................................................................... 24
7.5 AMP FUSE ............................................................ 25
FUEL PRIMER SWITCH ............................................ 25
START-STOP SWITCH .............................................. 25
STARTER CONTACTOR RELAY
& STARTER MOTOR ................................................ 26
S SE EC CT TIIO ON N 6 6::
T TR RO OU UB BL LE ES SH HO OO OT TIIN NG G F FL LO OW WC CH HA AR RT TS S ........................................ 2 27 7--3 37 7
IF PROBLEM INVOLVES AC OUTPUT ...................... 27
PROBLEM 1 -
VOLTAGE & FREQUENCY ARE BOTH
HIGH OR LOW ............................................................ 27
PROBLEM 2 -
GENERATOR PRODUCES ZERO VOLTAGE OR
RESIDUAL VOLTAGE (5-12 VAC) ........................ 28-29
PROBLEM 3 -
NO BATTERY CHARGE OUTPUT .............................. 29
PROBLEM 4 -
EXCESSIVE VOLTAGE/FREQUENCY DROOP
WHEN LOAD IS APPLIED .......................................... 30
PROBLEM 5 -
PRIMING FUNCTION DOES NOT WORK
(GASOLINE MODELS) ................................................ 30
PROBLEM 6 -
ENGINE WILL NOT CRANK ...................................... 31
PROBLEM 7 -
ENGINE CRANKS BUT WILL NOT START
(GASOLINE UNITS) .................................................... 32
PROBLEM 7 -
ENGINE CRANKS BUT WILL NOT START
(LP UNITS) .................................................................. 33
PROBLEM 8 -
ENGINE STARTS HARD AND RUNS ROUGH
(GASOLINE UNITS) .................................................... 34
PROBLEM 8 -
ENGINE STARTS HARD AND RUNS ROUGH
(LP UNITS) .................................................................. 34
PROBLEM 9 -
ENGINE STARTS THEN SHUTS DOWN .................. 36
PROBLEM 10 -
7.5 AMP (F1) FUSE BLOWING .................................. 37
S SE EC CT TIIO ON N 7 7::
D DIIA AG GN NO OS ST TIIC C T TE ES ST TS S ............................................................................ 3 38 8--6 67 7
INTRODUCTION ........................................................ 38
TEST 1 -
Check No-Load Voltage And Frequency ...................... 38
TEST 2 -
Check Engine Governor .............................................. 38
TEST 3 -
Test Excitation Circuit Breaker .................................... 39
TEST 4 -
Fixed Excitation Test/Rotor Amp Draw ........................ 39
TEST 5 -
Wire Continuity ............................................................ 40
TEST 6 -
Check Field Boost ........................................................ 41
TEST 7 -
Test Stator DPE Winding.............................................. 41
TEST 8 -
Check Sensing Leads/Power Windings ...................... 42