We break down what to look for when troubleshooting electrical faults. Learn more about troubleshooting logic and how it will help you identify common electrical faults.

1. Troubleshooting Electrical Faults
How to Identify Common Electrical Faults

2. Electrical Fault, Defined
• An electrical fault is an abnormal
condition caused by equipment failure or
wiring defects
• Causes machinery or devices to
malfunction
• Can bring entire production lines to a halt
• Typically either an open circuit, short
circuit, or both

3. IdentifyingElectrical Faults
• Open Circuit – some part of the
circuit will not be operating
isn’t receiving voltage
• Look for:
• Burned out light bulbs
• Open operating coils
• Loose connection or terminal points
• On equipment with continually
wires, there may be a broken
inside the insulation

4. IdentifyingElectrical Faults
• Short circuit – occurs when
insulation around a conductor
deteriorates and current is
elsewhere (grounded)
• Causes fuses or circuit breakers to
• Could also energize other parts of
circuit and cause these parts to
unintentionally

5. IdentifyingElectrical Faults
• Low voltage – can cause relays to
chatter or not pick up
• Motors and components with coils
heat up more than normal
• Overheating can cause electrical
insulation to deteriorate and
fail
• Over voltage – generally shortens
the lifespan of components due to
overheating
• Lighting, motors most commonly

6. IdentifyingElectrical Faults
• Electro/mechanical – usually
happens to old components or
manufacturing defects
• Often exhibits no exterior signs of
problems
• Includes things like:
• Pushbutton that no longer closes
pushed
• Relay with stuck/welded contacts

7. TroubleshootingLogic
• Before troubleshooting – follow
company safety rules and
procedures
1. Observation – use senses to find
signs of malfunctions
- Visual: e.g. loose components, parts
in bottom of cabinet, overheating
components
- Hearing: e.g. abnormal sounds
- Touch: e.g. excessive heat or loose
components
- Smell: e.g. burnt insulation

8. TroubleshootingLogic
2. Define problem areas
-Test equipment if possible and note
working and what isn’t
-Rule out any properly functioning part
circuit from the problem
3. Identify possible causes
-List probable causes and rate each by
probability
- E.g. blown fuses, mechanical
windings and coils, terminal connections,

9. TroubleshootingLogic
4. Test probable cause
-Start with most probable cause
-Know what to expect before taking a
reading
-Know what it means if meter reading
unexpected
-After testing, may need to sectionalize
circuit further to reduce the problem
-Repeat until suspect component/wire

10. TroubleshootingLogic
5. Replace component and test
operate
-Once component is proven
replace it and test operate the
circuit
-Check all features and operations
circuit
-Return the equipment to service if
operating correctly
-If not, return to step one

11. Other Tips
• Never underestimate the power of your
own senses in determining faults
• “Burnt insulation” smell is almost always
a good indication of a failed component
• Listen for abnormal sounds when
operating a device
• Look for visual signs of burning
• Be careful when working with hot equipment