This document discusses methods used to minimize arc flash hazards in an electrical switchroom for a basalt crushing and screening plant. It describes implementing multiple risk controls following the hierarchy of hazard control, including installing an arc flash rated switchboard with features like arc venting, segregation and arc flash reduction technology. The design used studies to reduce fault current and clearing times, and allowed remote operation and monitoring to minimize worker exposure. This combination of engineering and administrative controls successfully lowered hazard categories, reducing required personal protective equipment without compromising coordination.

1. BY DANIEL HALL
HITECH ELECTRICAL AUTOMATION
How to “Mitigate” Flash Hazards in a Main Switchroom

2. Objective for this presentation
To share examples of utilizing multiple high level risk controls to minimize flash hazards in a Switchroom to the point that special arc flash PPE is not required for many switching and isolating procedures.
To create a safer work environment for operational and maintenance staff.
Category
4 PPE

3. Topics to be discussed in this presentation
1.
The project
2.
The Hazards and Risks in the Main Electrical Switchroom to take into consideration
3.
Planning and engineering philosophy for minimizing the Hazards
4.
Outcomes achieved and summarized conclusion

4. The Project
The Customer:
Hanson Construction Materials
Location:
East Guyong situated half way between Bathurst and Orange NSW.
Scope of works included:
Turnkey solution for the supply and installation of a fixed basalt crushing and screening plant with a capacity of 220 TPH.
Design, engineering, supply, installation and commissioning LV electrical works including the Process Control System (PCS) and appropriate Switchroom and MCC’s.

5. 1.
2MVA Transformer
2.
Switchroom
3.
MCC and Control Panels
4.
Three Crushers
5.
Four Screens
6.
Six Feeders
7.
Eleven Conveyors
8.
Three Luffing and Radial Stackers
9.
Dust Extraction
10.
Lighting and general power
11.
Automation of plant
The Project
The key equipment:

6. The Hazards and Risks
Generally Quarrying sites of this size do not have permanent electrical staff onsite
A lot of contractors who do work on these sites generally do not do a lot of work on mining sites
Therefore the primary hazard area’s the design team considered throughout engineering the Switchroom were as follows:
1.
Switching and isolation of Electrical devices.
2.
Resetting of overloads.
3.
Fault finding and testing.

7. 1.Racking in or out Circuit Breakers.
2.Removing or installing Circuit Breakers.
3.Working on Control circuits with energized parts.
4.Low Voltage testing and fault finding.
5.Removing panels for inspections and other activities
6.Testing for Dead
The Hazards and Risks
Examples of activities in a Switchroom which involve Arc Flash Risks

8. 1.
Dust
2.
Dropping tools
3.
Accidental touching
4.
Condensation
5.
Material failure
6.
Corrosion
7.
Faulty Installation
8.
Over-voltages across narrow gaps
The Hazards and Risks
Common causes of Arc Flash in a Switchroom

9. 1.
Proximity of the worker to the hazard
2.
Temperature
3.
Time for the circuit to break
The Hazards and Risks
Three main factors which determine the severity of an arc flash

10. What are your Risks
1.
Compliance – Failing the standards and the rules can delay project startup and can result in significant fines
2.
Injury/Death – Yourself, your co-workers, outside contractors and other third parties. Between 5 and 10 arc flash incidents happen every day
3.
Equipment damage – Costly to repair or replace
4.
Plant shutdown – reduced productivity, lost revenues, lost costumers, lost jobs
5.
Liability – Lawsuits, higher insurance premiums, out of pocket costs if self insured – a single incident can easily run in excess of $10M

11. Typical Results from an Arc Flash
Pressure Waves
Copper Vapor:
Solid to Vapor
Expands by
67,000 times
Molten Metal
Intense Light
Hot Air-Rapid Expansion
Extreme Heat
20,000 °C
Shrapnel
Sound Waves

12. Planning and Engineering for Minimizing Hazards
Our principle for planning to minimize the hazards was to follow the Hierarchy of Hazard Control

13. 1.
Label Equipment & Train Personnel on Good Safety Practices
2.
Reduce Available Fault Current
3.
Shorten Clearing Time
4.
Move People Further Away
5.
Redirect Blast Energy
6.
Prevent Fault
Methods/Technologies to Reduce Arc-Flash Energy, Protecting Personnel and Equipment
Planning and Engineering for Minimizing Hazards
Both work to
Reduce Energy

14. Planning and Engineering for Minimizing Hazards
Power Engineering Studies Required to move forward
1.
Load flow studies
2.
Protection coordination studies
3.
Arc Flash Analysis
4.
Touch and Step Potentials
5.
Earthing system design and features
Gain a full understanding of the Fault levels in the installation.

15. Planning and Engineering for Minimizing Hazards
Begin the Equipment Selection Process
1.
Create a working Single Line Diagram from the engineering studies to start designing the MSB
2.
Take into consideration the fault levels and Arc Flash Levels at each point
3.
Start the design on the MSB considering the area’s at which maintenance and operational staff will need to access
4.
Investigate switchboard manufactures who can best offer solutions to our designs and Arc Flash Hazard Reductions.
5.
Start adding features and new technology to the MSB to further enhance the safety of the MSB

16. Planning and Engineering for Minimizing Hazards
Our Selection of the Main Switchboard
Eaton xEnergy Low Voltage Main Distribution
The Reasons for selection
1.
Type Tested Switchgear assemblies
2.
IP Rated to IP55
3.
The xEnergy system is modular and designed for increasing future requirements
4.
The Arc Fault Containment Features available
5.
The new Technology of Arc Flash Reduction Maintenance System available on Main Air Circuit Breakers
6.
Cost/ availability and proven product reliability

17. Planning and Engineering for Minimizing Hazards
Switchboard Features
The xEnergy switchboard system consists of IEC/EN 60439/61439 Type-Tested Function modules which provide compliance with AS3439.1
Arc Fault Containment features:
1.
Arc Relief Valve directing gases and heat to a designated area away from personal
2.
Form 3b/4a segregation
3.
Internal penetration seals
4.
Insulation Arc Barriers
5.
Creation of Arc Free Zones through additional partition walls to allow true segregation to comply with the design

18. What is ARMS?
Planning and Engineering for Minimizing Hazards
Eaton Air Circuit Breakers Arc Flash Reduction Maintenance System
Switchboard Features

19. Planning and Engineering for Minimizing Hazards
Switchboard Features
ARMS Technology TM Overview
ARMS is a separate integral analog circuit that when enabled in the Maintenance Mode, ARMS TechnologiesTM provides an accelerated instantaneous trip to reduce arc flash (system can trip as fast as 18ms!)
Local and remote enabling and indication capabilities are provided as well as consideration for Lock-out/Tag-out procedures

20. Planning and Engineering for Minimizing Hazards
Benefits of the ARMS System
Increased worker safety – when enabled, the Arc flash Reduction
Maintenance System provides an accelerated instantaneous trip to reduce arc flash.
Reduction in incident energy levels may allow reduced levels of
PPE to be used, offering an improvement to worker comfort and
mobility.
When properly applied, the hazard risk category frequently can be
lowered multiple categories permitting less PPE.
PPE SHOULD ALWAYS BE THE LAST LINE OF DEFENCE

21. Planning and Engineering for Minimizing Hazards
Disadvantages of the ARMS System
Time- Current Curves
Coordination is Lost
Without ARMS
With ARMS Activated
We believe this is a small trade off during maintenance mode when you know you are exposing people to a higher level of RISK
Once people are away from the risk and ARMS is switched off, all normal settings are back in place

22. Planning and Engineering for Minimizing Hazards
How we implemented the ARMS System
Elements associated with the ARMS system
1.
Airlock Room outside the Main Switchroom where the remote ARMS activation switch is located
2.
Remote indication inside Airlock room
3.
Motion Detectors inside the Main Switchroom
4.
Indication and Alarms through the SCADA System
Airlock Room Segregated from Main Switchroom

23. Planning and Engineering for Minimizing Hazards
How we implemented the ARMS System
Remote Switch Activated
ARMS Activated
SCADA Messages and Alarms
Motion Detector Activated
SCADA MESSAGES
1.
Remote ARMS switch activated
2.
Remote ARMS switch de-activated
3.
Personnel in Main Switchroom
SCADA ALARMS
1.
Personnel in Main Switchroom without activating ARMS switch
2.
Personnel in Main Switchroom and no movement detected

24. Planning and Engineering for Minimizing Hazards
Maintenance Mode Schematic
Remote mounted switch control
Remote switching and indication via communications
Remote mounted indication

25. Planning and Engineering for Minimizing Hazards
SLD Overview

26. Layout of Main Switchboard
Switchboard WITHOUT ARMS
Cabinet Category levels
Planning and Engineering for Minimizing Hazards
CAT 0
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 4
CAT 0
CAT 0
CA T 0
CAT 0
CAT 0
CAT 0

27. Layout of Main Switchboard
Switchboard WITH ARMS Cabinet Category levels
Planning and Engineering for Minimizing Hazards
CAT 0
CAT 4
CAT 4
CAT 0
CAT 0
CA T 0
CAT 0
CAT 0
CAT 0
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1
CAT 1

28. Planning and Engineering for Minimizing Hazards
Labelling- ACB WITHOUT ARMS Activated

29. Labelling- ACB WITH ARMS Activated
Planning and Engineering for Minimizing Hazards

30. Planning and Engineering for Minimizing Hazards
Eliminate the need for operators to enter the Main Switchroom
The use of Electronic Thermal Overload Protection Devices on all “DOL” equipment allows the operators to reset motors in Overload conditions through the SCADA system. Magnetic Trips still require an Electrician to attend site and investigate this type of fault.
We selected the use of the Allen Bradley “E3 Plus” Electronic TOL Devices
The E3 Overload Relay is a multi-function solid-state microprocessor-based
electronic overload relay for the protection of squirrel-cage induction motors
rated from 0.4…5,000 A
Overload Protection

31. Planning and Engineering for Minimizing Hazards
E3 Plus Electronic TOL
Magnetic Trips Electrician Required
Thermal Trips Remotely Reset by Operator through SCADA System

32. Planning and Engineering for Minimizing Hazards
Eliminate the need for operators to enter the Main Switchroom
Remote Switching of all Circuits 800A and above with a remote switching panel in Air Lock Room outside of the Main Switchroom
Eliminates the need for the operator or maintenance staff to put themselves in proximity to the Hazards
Remote Switching

33. Eliminate the need for operators to enter the Main Switchroom
Planning and Engineering for Minimizing Hazards
Viewing Windows to all access doors to allow condition observation before entry
Break Glass switches to all access doors to Trip the Main Switch and Activate the Fire Suppression System without entering the Main Switchroom
Fire Suppression System Activation will also Trip the Main Switch without entering the Main Switchroom
Switchroom Hazards

34. Administration for Minimizing Hazards
Protect your Protection settings by sealing them once they are set in accordance to the engineered studies
Administration
Create good maintenance schedules for Plant and Equipment
Training and Education to all Staff
Specific training in regards to reading and understanding Arc Flash Labelling. There are still a lot of Electrical Staff out there who do not understand Arc Flash Labelling and the potential energy levels they are about put themselves at Risk to.
Display the Current SLD in the Switchroom showing all protective settings and Arc Flash Levels so that they are always accessible.
Create a culture of safety and assessing Risks.

35. PPE The Last Defense
Arc Flash PPE labelling installed at all area’s of Risk
Educate staff on PPE requirements
Ensure all PPE is accessible at all times for all locations
Reducing the Hazards will Reduce the level of PPE
The higher the level of PPE required the more Hazards maybe introduced such as Heat Stress, Poor Visibility and Limited Body Movement

36. Summary
In conclusion to this presentation we have shared examples of utilizing multiple high levels risk controls to minimize flash hazards in a Switchroom
We have demonstrated through the use of “The Hierarchy of Hazard Control” how we have Eliminated, Substituted, Engineered and administrated Risk controls
We have demonstrated how we have reduced the level of PPE required to work in and around our Switchboards

37. Thank You
www.hitechelec.com.au