NFEC FIRE SAFETY SEMINAR Krish Mysore

Transcription

1 NFEC FIRE SAFETY SEMINAR 2018 Krish Mysore

2 Agenda 1 Electrical Fire Stats 2 Types of Electrical Fires 3 Electrical Risk Management 4 Electrical Health Check Assessment 5 Case Study 6 Conclusion

3 Statistics On Electrical Fires 2017 Causes of Fire Commercial Premises Industrial Premises 43% 8% 21% Machnine Overheating Exposure to Heat Source Naked Light 29% 1%4% 13% 5% 4% 8% Machine Overheating Overheating of Food Naked Light Drop Light 1% 27% Hot Works (Welding/Cutting Torch) 36% Electrical Origin Others Electrical Origin Sparks

4 Types Of Electrical Fire Electrical Fires over charging of batteries in electronic devices, equipment overloading, short circuit and insulation failures

5 Electrical Fires Battery Charging Fires from charging of batteries can be attributed to: 1 2 Overcharging Leaving battery unattended while charging Charging of non OEM or third party battery Charging battery with other appliance on same source (sharing loads) Faulty product by nature 3 4

6 Overloading Overloading occurs when excessive current flows beyond the rated current capacity When a circuitry becomes overloaded, the excessive currents can cause heating, melting and insulation damage to the wires/cables, possibly starting an electrical fire

7 Electrical Fires Insulation Failure Insulation in electrical equipment is to protect and separate electrical conductors without allowing current to pass through them Failure of these insulation can lead to short circuit or overheating resulting in fire Common causes of insulation failure includes: 1 2 Poor maintenance of equipment Electrical stress (high current and voltage stress, harmonics) Physical stress (bending of wires and cables) 3 4

8 Electrical Fires - Connections Improper or loose connections to an electrical equipment can cause fire due to: 1 2 Over heating due to high resistance Arcing due to frequent making and breaking of contacts Under-sized wires catching fire during short circuit 3 4

9 Electrical Fires Short Circuit Occurs when current takes an unintended less resistive path between two nodes of an electric circuit at different voltages (phase & ground), resulting in high current flow This high current flow dissipates high power, causes over heating, damage to insulation and fire by combustion of nearby flammable materials Common causes of short circuit includes: Wrong connection (ground to live phase) Bypass safety system (interlock)

10 Electrical Fires Arc Flash Arc Flash is the result of an arcing fault in electrical switchgear caused by faulty equipment or by human mistakes, resulting in severe damage to equipment and even fatal injury Some characteristics of arc flash are: Intense light and very loud sound may cause blindness and deafness Shock due to pressure and sound waves Hot molten metal and temperature of 19,400 C Simulation done with dummy

11 Electrical Fires Arc Flash Occurs due to one or more of the following: Accidental dropping of tools on to live parts in electrical switchgear Switching on to live part during maintenance Condensation inside the switchgear (presence of rust) Intense dust penetration into the switchgear Material failure Picture courtesy of GIPHY Faulty Installation

12 Risk Management According to MOM website, Risk Management is defined as: Employers, self-employed persons and principals are responsible for identifying safety hazards at workplaces and taking steps to eliminate or reduce the risks. This includes assessing, controlling, monitoring, and communicating risks. Risk Management process consists of Identifying, Evaluating and Controlling risks Risk Management can be implemented anywhere Identify Evaluate Control

13 Electrical Risk Management Risk management for a facility can be applied by an electrical assessment / audit For commercial and industrial sites, it is important to conduct an external non-biased electrical health check assessment / audit Some countries, for example, Philippines have adopted mandatory performance audit on all electrical facilities in power industry

14 Electrical Health Check Assessment The objective of the assessment should be to identify all electrical hazards, evaluate and prioritize them according to risk levels and provide owners control measures(solutions) to either eliminate or mitigate those risks The recommended solutions should also include on how to increase the performance of the facility by adapting solutions with current and new industrial technologies (Digital Services) Equipment damage such as these could have been avoided with an electrical health check assessment

15 Electrical Health Check Assessment Identify Flammable chemicals placed near electrical panels Improper cable size and type for transformer neutral Flammable materials near electrical panels Risk: Fire Risk: Fire Risk: Fire

16 Electrical Health Check Assessment Identify LOTO not implemented Exposed live parts such as busbars are exposed; Obsolete CB Transformer oil leaking Risk: Arc Flash, electrocution Risk: Arc flash, fire, electrocution Risk: Insulation damage, fire

17 Electrical Health Check Assessment Identify Lack protection coordination resulting in improper tripping Risk: Wrong tripping, fire, electrocution Damaged capacitors due to high harmonics can cause fire Risk: Fire Unsafe electrical equipment installation Risk: Arc flash, fire, electrocution

18 Electrical Health Check Assessment Evaluate and Prioritize Each identified hazard must be evaluated and prioritized according to the risk. The purpose of the chart below is to enable that. Hazard Risk Risk Level Solution Damage to cables insulation Electrocution, short-circuit Critical Replace cables Transformer oil leak Insulation damage; electrical fire Mandatory Repair leak and conduct DGA test LOTO equipment and procedure not available Electrocution, arc flash, electrical fire Mandatory Obsolete equipment (Circuit Breaker) Equipment failure Minor Secure offline breakers with LOTO devices Replace with new type or perform in-depth tests Risk Level Description Deadline Critical Mandatory Minor Very severe hazard posing immediate danger to facility / personnel or not complying to regulatory requirements. Serious hazard, not necessarily posing immediate danger or expose facility to any immediate legal recourse Business critical or requires improvement through regular maintenance or replacement < 1 month < 3 months < 12 months

19 Electrical Health Check Assessment Control Control measures are intended to prevent electrical fires which includes Maintenance Non-continuous Continuous online monitoring Partial discharge, breaker diagnostics, harmonics Regular maintenance, infrared thermography Equipment replacement

20 Diagnostics Based Preventive Maintenance Diagnostics based maintenance involves conducting very specific tests For example, trip test done during preventive maintenance checks if protection operates (current injection relay/trip unit operates circuit breaker operates) But how often or at all do we check the condition of the circuit breaker s mechanism which is critical Opening and closing times Opening and closing speeds Overtravel and stabilization Wear of arcing contacts Contact and insulator resistance

21 Diagnostics Based Preventive Maintenance Other applicable in-depth diagnostics Protection characteristic test Partial discharge test Harmonics analysis These in-depth diagnostics need not be done annually but perhaps every 3-4 years

22 Condition Based Predictive Maintenance Predictive maintenance is equipment condition monitoring using advanced sensors and analytics Sensors send critical information such as temperature and humidity at places difficult to capture from infrared thermography Reduce (not eliminate) periodic maintenance which requires shutdown Forecasts maintenance based on condition of equipment Implement different level of alarms Eliminates arc flash risks for personnel doing infrared thermography on live electrical equipment (MV switchgear, transformers, main LV switchboards) Still recommended to do regular preventive maintenance on small panels and DB boards (Infrared thermography)

23 Condition Based Predictive Maintenance Alarms SMS alerts Wireless sensors Cloud Customized dashboard Reports Thermography camera Yearly preventive maintenance record

24 Case Study An electrical assessment was done on a commercial building in to assess the risks Auditors found numerous risks which included: Electrical fire hazards Electric shock hazards Faulty electrical equipment due to improper maintenance Recommendations were provided in the report to eliminate or mitigate those risks Customer decided to wait and possibly did not do anything Two years later, an electrical fire from power cable near a generator fuel tank caused it to ignite

25 Comparison of Before and Aftermath Distribution transformer before the fire incident Transformer and adjacent structures including cable trays is completely destroyed

26 Comparison of Before and Aftermath HT switchgear before the fire incident HT switchgear completely destroyed after the incident

27 Comparison of Before and Aftermath LV Distribution panels before the fire incident LV Distribution panels after the fire incident

28 More of Aftermath

29 Key Takeaway Point Conducting an assessment is important but becomes ineffective if the recommended control measures and solutions are not addressed and implemented Identify Evaluate Control

30 Conclusion Electrical fires are as dangerous as any other source of fires and should be prevented Risk management for industrial and commercial facilities is critical and should be done before disaster occurs An on-biased electrical health check assessment conducted by an external person is recommended Recommended control measures from the assessment should be strictly followed and completed within the time frame Maintenance should be made integral part of the operations for facilities Preventive maintenance with in-depth diagnostics should be considered to prevent any risk of electrical fire Predictive maintenance can be implemented as long term solution to reduce OPEX

31 Thank You For Your Attention