Section 1.7 - General Troubleshooting; Introduction; Recommended Tools; Troubleshooting Reminders And Tips - Generac Power Systems CorePower Repair Manual

Section 1.7
General Troubleshooting

INTRODUCTION

This section familiarizes the service technician with the
manufacturer recommended procedures for the testing and
evaluation of various problems that can occur on the standby
generators. It is highly recommended that you read these
introductory tips before you attempt to troubleshoot any of the
three main generator components: AC Generator, Engine, or
the Transfer Switch. The Troubleshooting Flow Charts provide
the simplest, quickest, systematic means to troubleshoot the
typical problems that might occur during the lifetime of the unit.
If you use the flow charts and perform the indicated tests, you
will be able to identify the faulty component, which can then be
repaired or replaced as necessary.
The test procedures in each section do require a basic
knowledge of electricity and electrical safety, hand tool skills,
and use of Volt-Ohm-Meters.

RECOMMENDED TOOLS

In addition to the normal hand tools required, some test
procedures may require the use of specialized test equipment.
At a minimum you must have a meter that measures AC
voltage and frequency, and DC voltage and current (digital
multi meters (DMM) are recommended); standard meter test
leads, a set of piercing probe leads , and a set of pin probe
leads for the connector pins. The manufacturer carries a set
of acceptable piercing probes (PN 0G7172), or other suppliers
piercing probes may be used. Fluke provides a high quality
piercing probe, PN AC89, which is highly recommended. The
manufacturer also carries a set of flexible pin leads for use with
the connector plugs (PN 0J09460SRV).
Figure 13. Test Probes
For engine troubleshooting you will need a good manometer
which measures low pressure in Inches of Water Column (IN
WC or IN H20). An ignition spark tester is also a handy tool to
have when working with air-cooled engines.
Testing and troubleshooting methods covered in each section
are not exhaustive. No attempt has been made to discuss,
evaluate and advise the home standby service trade of all
conceivable ways in which service and trouble diagnosis must
be performed. Accordingly, anyone who uses a test method
not recommended herein must first satisfy himself that the
procedure or method he has selected will jeopardize neither
his nor the products safety, and will not cause damage to any
connectors or components.
Page 22
PART 1
Recommended Tools Check List
p General Mechanics Tool Box
p A Meter Capable of Measuring Frequency (Hz), AC & DC
volts, DC amps, and Ohms
p A Clamp-on Ammeter
p A 1/4" & 3/8" Metric & SAE Socket Set
p Allen Wrenches (Metric & SAE)
p Manometer
p Spark Tester
p Compression Gauge
p Oil Pressure Gauge
p Leak Down Tester

TROUBLESHOOTING REMINDERS AND TIPS

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. Use the flow chart index for the
part of the generator you are working with. If it is problem with
voltage, use Part 2 – AC Generators; for engine problems use
Part 4 – Engine/DC Control; for a problem with the transfer
switch, use Part 3 – Transfer Switch. The index for each will
help you clarify the problem and the flow chart to use. In each
flow chart start at the top and use the test indicated to verify
whether a component or control item is working properly or not.
At the end of each test follow the "good" or "bad" arrows and
perform the next test.
It is always good practice to continue to ask questions during
the troubleshooting process. When evaluating a problem, these
questions may help identify the problem quicker.
• What is it doing? (low voltage; not cranking; not transferring;
etc)
• What should it do? (run and start; transfer; shutdown; etc)
• Does the same thing happen each time?
• When is it happening?
• What could or would cause this?
• What type of test will either prove or disprove the cause of
the fault?

CONNECTORS

A number of the tests require the use of a volt-meter and a set
of wire piercing probes. When using the piercing probes make
sure you use some liquid tape or silicon to coat the insulation
where you pierced it; this will keep moisture out and prevent
long term corrosion.
It is very easy to damage the female pins in the connectors
on the control panel and the C1 connector (Molex connector)
which goes to the alternator can.
DO NOT ATTEMPT TO PUSH PROBE TIPS INTO THE FEMALE
PINS OF THE MOLEX CONNECTORS; doing so will damage the
female pin which will create another problem. Use the piercing
probes on the correct wire to check for the appropriate voltages
; or use the flexible pin leads, available from the manufacturer
(PN 0J09460SRV) to work with the connector plugs.
GENERAL INFORMATION