1 1 automatic power cut-off device for electricity distribution board construction safety week...

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Automatic Power Cut-off Device for Electricity Distribution Board

Construction Safety Week

Innovative Safety Initiative Award 2013

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Temporary Electricity Distribution Board• Temporary Electricity Distribution

Board (EDB) is essential for construction site before the permanent power is ready for use.

• To avoid person contacting with live parts of EDB, a door is provided and a pad-lock is installed

• To warn workers not to open the door, there is a warning notice

• If power is tripped, worker should call the REW with contact number printed on EDB

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Problems to be tackled

• Major stakeholders have put the “lock” requirements in contract, audit checklist, in-house rule etc.

• However, non-compliances (Lock damaged, not closed the door) repeat project to project, day to day ..

• Lot of resources are being wasted in chasing who damage the lock, issue warning letter, disciplinary procedures, handling client complaint, follow up auditor’s findings, meeting, training etc … …

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Issues to be tackled – Deep Dive

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Way Out for the Unsafe Act

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Solution – Automatic Power Cut-off Device Development Roadmap and Timeline

• Dec 2011 – Set up working group

Lead by : Safety Manager

EM Construction Manager - REW

EM Project Manager - REW

Senior Electricity Foreman - REW

Electricity Foreman – REW

Safety Officer

Supplier

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Design Criteria

• EDB provide electricity to both sockets and temporary lighting, trip off the socket should not trip off the lighting at the same time

• When the door is opened and the power to the socket is tripped off, close the door, the power shall not be suddenly resumed.

• Power resume must be done by REW after disconnect all the socket connections (To prevent sudden restart of equipment)

• To warn workers not to open the door – Warning Notice

• To warn workers when illegally open the door – Alarm system

• To let REW to know which EDB is altered, Flash light indication

• Material cost must be affordable

• Installation must be simple and can be done by site REW.

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Development Roadmap and Timeline

Jan 2012 – Design and Built Prototype

Developed at Central Police Station Project

Circuit Diagram jointly approved by Construction Manager (EM) and Project Manager (EM)

Supplier to supply material

REW to install

Modify existing EDB with the Automatic Power Cut-off Device

Material cost for a “64A capacity EDB” : HK$1500.

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Jan 2012 – Develop Prototype

Emergency Stop Flashing Alarm

Magnetic Contactor REW Key slot Micro-switch

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2 February 2012 – First Prototype Ready for Trial


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Warning Flash

Emergency Stop

REW Key

3 colour Status Lamp

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Emergency Stop

Press the button – All power to output socket will be OFF

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REW Key

Key insert for reset or for maintenance/testing by REW

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Warning Flash

Flashing when door is illegally opened (With siren)

When door is closed, still flashing but siren stop

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3 colour Status LampTo indicate Status of EDB

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3 colour Status Lamp

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March 2012 – Supported by Top Management

Modified all Building Projects existing EDB Total 250 Nos of EDB Estimated material cost $400,000 Target to complete within 3 month (Before June 2012)

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April 2012 – May 2012

Discuss with Supplier to built-in the device into newly ordered EDBAdditional Cost (Material and Labour) for 64A EDB ~ $1800

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Mar 2012 – Aug 2012 : Feedback after Trial

Pros :• No more lock damage incident as worker start to know that open

the door, they will not get the power• The only way to get the power is to call the REW.• Affordable price ( $1500 to $1800 per EDB)• Good comment from various clients (Public and Private) and from

assessors during for Considerate Contractors’ Award Assessment

Cons :• Sealing of the Add-on device create water proof problem to EDB• Some naughty worker will press on the Emergency Button• When door is illegally opened, all power to sockets will be cut and

will affect the production if there are many naughty workers

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Sept 2012

• Further affirmed by Top management as a Gammon Group Policy • All newly ordered EDB must be installed with this Built-in Device

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Other accessories

Switched 110V Power Strip

• Individual overload circuit beaker and ELCB• Power strip shall trip before EDB is tripped• Convenient for use reduce cables from EDB• IP 44 Standard• Approx $750 per set

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March 2013

Contract No. SS X301Redevelopment of Kwun Tong Swimming Pool Complex and

Kwun Tong Recreation Ground Project

Selected as Project represent Gammon for the competition

Construction Safety Week

Innovative Safety Initiative Award

2013

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Fan - Connect to socket Lamp - Direct from EDB

Construction Safety WeekInnovative Safety Initiative Award 2013 - Video

Illegal Opening EDB Door

• Illegal Open the door

• Alarm activate

• Flash and Siren

• Power to Fan : “OFF”

• Power to Lamp : “ON”

• Close the door

• Siren “OFF”, Flash “ON”

• Still no power to Fan

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Reset the EDB

• Turn off the Fan

• Unplug the socket

Prevent sudden power on and sudden start of equipment

3. Insert REW Key

4. Reset the device / Flash stop

5. Power to socket resume

6. Plug Fan’s socket

7. Turn on the Fan

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Maintenance and Testing of EDB

• Insert REW Key

• Open the Door

• Power to Socket and Fan : ON

• Close the door and Lock

• Remove REW Key

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Construction Safety WeekInnovative Safety Initiative Award 2013

This is a creativity, unique with concept of innovation in HK.

We are glad to see the innovation has resulted in practical outcomes and the safety performance in electricity safety is improved.

Worker are no longer opening the EDB thus with lesser chance to be electrocuted.

The affordable cost and simple installation made this device a cost effective innovation that can be widely used within the construction industry for Civil, Building, E&M, Maintenance, A&A projects whenever temporary EDB is used.

Last but not least : Lesser resources in handling EDB lock being damaged allow more time for managing other safety issues

Automatic Power Cut-off Device for EDB

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Construction Safety WeekInnovative Safety Initiative Award 2013

End of Presentation

Automatic Power Cut-off Device for EDB

1 1 automatic power cut-off device for electricity distribution board construction safety week...

Documents

rew slide

timeline slide

edb slide

material rew

site rew

trial development roadmap

timeline rew key key

prototype ready