Guardian 4389 Repair Manual page 97

DC CONTROL
Problem 14 - Unit Starts and Transfer Occurs When Utility Power Is Available
TEST 71 -
GOOD
CHECK N1 & N2
VOLTAGE
BAD
TEST 28 - CHECK
UTILITY 1 &
UTILITY 2
TERMINALS
GOOD
REPAIR N1/N2 OPEN WIRING
BETWEEN TRANSFER SWITCH
AND GENERATOR
Problem 15 - Generator Starts Immediately in Auto - No Transfer to Standby.
TEST 73 - TEST
GOOD
SET EXERCISE
SWITCH
BAD
REWIRE OR
REPLACE
PART 4
TEST 65 - TEST
TRANSFORMER (TX)
VOLTAGE OUTPUT
BAD
REPLACE
TEST 30 - CHECK
BAD
FUSE F1 & F2
BAD
REPLACE
GO TO PROBLEM 7,
PAGE 3.3-2
Utility Voltage is Present
TEST 43 - TEST
AUTO-OFF-MANUAL
SWITCH
BAD
REPLACE OR CORRECT
WIRING
TROUBLESHOOTING FLOW CHARTS
TEST 72 - CHECK
UTILITY SENSING
GOOD
VOLTAGE AT CIRCUIT
BOARD
TEST 27 - CHECK
VOLTAGE AT
GOOD
TERMINAL LUGS
N1 & N2
GOOD
REPAIR OR REPLACE WIRE
N1A/N2A BETWEEN N1/N2
LUGS AND FUSE HOLDER
TEST 74 - CHECK
REMOTE START
GOOD
WIRING IF EQUIPPED
BAD
REPAIR OR REPLACE
SECTION 4.3
REPLACE
GOOD
CIRCUIT
BOARD
REPAIR OR
BAD
REPLACE
WIRING
CORRECT
UTILITY
BAD
SOURCE
VOLTAGE
REPLACE
GOOD
CIRCUIT
BOARD
Page 95