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Safe & Effective Troubleshooting
Objectives
• Explain how training can save your company money.• Discuss proper safety guidelines while placing a work area
in an electrically safe condition and restoring equipment to operation, including PPE Selection and the Live-Dead-Live process.
• Explain safety concerns while troubleshooting and the proper safety techniques for live diagnostic testing:– Voltage measurements– Current Measurements– Insulation Testing
• Discuss Effective Troubleshooting Techniques using a Systematic Troubleshooting Approach
How to save $$$$ through training
• Electrical Safety training can save lives by:– Regularly reinforcing safe work practices– Providing employees with the information needed
to keep them safe– Helping to reduce the risk of electrical-related
accidents
What’s the real cost of a life lost or worker incapacitation?
• Initial insurance costs for medical treatment and disability payments.
• Indirect costs for investigation, production loss, overtime, replacement of equipment
• impact to site from a loss of experienced employee(s).
How to save $$$$ through training
• Minimize the potential loss of critical equipment through operational and technical training by:– Creating a more efficient operator/technician with the
ability to understand system response and quickly restore system redundancy and reliability
– Reducing the potential for personnel (human) error which can lead to unexpected loss of up-time
– Eliminating guessing (“Easter Egging” while troubleshooting) which often leads to replacement of the wrong component, resulting in reduced part replacement costs
Safety First!
Troubleshooting Work Practices
• Lock-Out/Tag-Out and check equipment de-energized whenever:– Ohmmeter readings are taken– Connecting clamp-on ammeter probes– Disconnecting or reconnecting wires– Replacing an electrical component– Performing visual inspections and/or adjustments
inside electrical enclosures
Beware!
• … of stored energies.– During the LOTO process, safety discharge
capacitors whenever present. Do not rely of bleeder resistor circuits.
– If troubleshooting removable ACB-type circuit breakers, discharge closing springs.
Energized Troubleshooting
• The appropriate level of shock/Arc Flash PPE is required.– Use installed Arc Flash Labels– Or NFPA 70E PPE Selection Tables
• Energized work permits are not required for diagnostic testing and troubleshooting.
Circuit Protection device operates
• Do not reclose breaker or replace fuse(s) unless:– It is known to be caused by an overload condition– Circuit has been inspected for down-stream
shorts.
Pre-Use Safe Glove Testing• Daily by user = once per shift, unless
damage is expected
• Visual and Air Check
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PPE for an Electrical Arc
Pressure Waves200 lbs/sq inch
Copper Vapor:Solid to VaporExpands by67,000 times
Molten MetalExtremely High Temps15,000- 35,000 °F
Shrapnel@700 mph
Sound Waves135+ decibels at 2ft
Intense Light
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Approach Boundaries
• Boundaries should be set around the work area to prevent:– unqualified workers from
coming into contact with live parts.
– Injury to those not in the appropriate level of PPE.
– Protect the worker
Note: shock boundaries dependent on system voltage level. For <600V the Limited Approach Boundary is 3.5 ft.
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Prohibited Shock Boundary: Authorized Qualified Persons Only. PPE as if direct contact with live parts.
Restricted Shock Boundary: Authorized Qualified Persons w/PPE
Limited Shock Boundary: Authorized Qualified Persons w/PPE. Unqualified allowed only when conducting OJT and accompanied by a qualified person
Flash Protection Boundary (FPB) – @ 1.2 Cal/cm2Flash Protection Boundary (FPB) – @ 1.2 Cal/cm2
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• Must wear appropriate PPE
• FPB based on available fault current and duration if an Arc Flash Analysis was performed. Values are listed on AF Label attached to equipment.
Distance of the Worker
• This incident energy exposure level shall be based on the working distance of the employee’s face and chest areas from a prospective arc source for the specific task to be performed.
480V MCC480V MCC
Know Your Meter!
• Know meter functions and how it is protected.• Know how to selected the right meter and its limitations:
– Always use CAT 3 (or higher) meter.– A low-budget meter may kill you.
• Know how to use a device to verify the absence of voltage, including interpreting indications/readings.
• Inspect meters for safe use.
Always “Test-Before-Touch”
• Conduct a “Live-Dead-Live” Test– Check meter on a know live source– Test the equipment (6-point check)
• Each Phase-to-phase• Each Phase-to-Ground
– Recheck meter on a know live source
Systematic troubleshooting approach
• “7-Step” Troubleshooting1. Preparation2. Observation3. Defined problem area4. Identify possible and probable causes5. Test6. Repair/replace and confirm7. Follow-up
Questions?
