Section 3 Troubleshooting Flowcharts; Introduction - Generac Power Systems GP Series Diagnostic And Repair Manual

Troubleshooting Flowcharts
Section 3

Introduction

The most important step in troubleshooting is identifying
the actual problem. The next step is to determine the
applicable flow chart to use to help diagnose the
problem.
For each flow chart, start at the top and use the indicated
test to verify whether or not a component or control item
is working properly. At the end of each test follow the
GOOD or BAD arrows and perform the next test.
If Problem Involves AC Output
VOLTAGE &
FREQUENCY BOTH
HIGH OR LOW
GO TO PROBLEM 1
(BELOW)
Problem 1 – Voltage and Frequency Are Both High or Low
TEST 5 - CHECK
STEPPER MOTOR
CONTROL
Diagnostic Repair Manual
FREQUENCY GOOD -
FREQUENCY GOOD -
VOLTAGE HIGH
ZERO OR RESIDUAL
OR
VOLTAGE LOW
GO TO VOLTAGE GO TO PROBLEM 2
REGULATOR
ADJUSTMENT,
PAGE 11
FREQUENCY IS GOOD,
BUT NO-LOAD
VOLTAGE IS HIGH
Use the flow charts in conjunction with the detailed
instructions in section 4. Test numbers used in the flow
charts correspond to the numbered tests in section 4. For
best results, perform all tests in the exact sequence
shown in the flow charts.
TEST 1 - CHECK NO
LOAD VOLTAGE &
FREQUENCY
ZERO VOLTAGE AND
ZERO FREQUENCY
VOLTAGE
GO TO PROBLEM 2
OR VOLTAGE
IS LOW
NO-LOAD VOLTAGE &
FREQUENCY GOOD -
VOLTAGE/FREQUENCY
FALLS OFF UNDER LOAD
GO TO PROBLEM 3
GO TO VOLTAGE
REGULATOR
ADJUSTMENT,
PAGE 11
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