Transcript 4a-Work Zone Kit Presentation

Dominion Virginia Power
System Protection
Human Performance Work Zone Kit
Mike Carden
*
804-257-4738
*Used with permission for WECC purposes
Dominion Virginia Power – System Protection
Overview
o
Responsible for construction, commissioning and maintenance of relay protection,
metering and data acquisition for Transmission - Distribution Substations (800) and
Generation (37) facilities.
o
Dominion has 120 System Protection Technicians positioned in 3 states. Typically a
2 year technical degree, electricity/electronics or instrumentation.
o
50% of our technician work force has < 3 years experience. We have also doubled the
number of “contract” electricians working our system (2008-2011).
o
Our Human Performance Program and Training is focused on eliminating the human
errors that cause inadvertent outages to the T&D power grid.
Human Errors Tracked By Event Since January 2008
Bumped Pnl
Accessed Wrong
Relay/Port
Missed Design
Error
Loss Of Pot
Shorted/Rolled
Wires
Loaded /
Jumpered
Wrong Point
Test Blades
Control Wiring
(Contractor)
Electric Transmission Work Zone Identification Kit
Designed to Aid in Eliminating Inadvertent Equipment Operations from
Wiring Errors, Jumpering Incorrect Points, Accessing Incorrect Panel/Device, etc.
Our Expectation: Use the Work Zone Identification Kit
o
When working on equipment or components that look similar.
o
When working on equipment or components that will be manipulated
multiple times.
o
When working on or near trip sensitive or risk important equipment.
Work Zone Identification Kit Insert (front)
Work Zone Identification Kit Insert (back)
Use Work Zone Identification Kit Banners
o
To create physical barriers (banners and hangers) to direct the worker to the
correct equipment and components and away from high risk equipment.
o
Text on banners used as reminder of our human performance tools and
terminology.
Use Work Zone Identification Signage and Flagging
o
When working on equipment that is out of service for testing and the equipment
requires signage or flagging for operational and/or safety reasons. Alerts others
on the job that testing is in progress.
o
Use flagging hangers when working on equipment or components that will be
manipulated for operational testing or placed into an abnormal condition during
testing period (i.e. scada control switch, breaker control switch, device power
on/off switch).
Red- Do Not Operate Green-Equipment Under Test Yellow-Abnormal Condition
o Wire caps will be used to
provide an insulated cover up
for wires and lugs during
transitional periods such as
construction jobs.
oWire caps are color coded:
oRed caps for new wiring
that is to be terminated in
the future.
oGreen caps for wiring
that is being removed.
oYellow caps for
temporary conditions.
oWire caps are sized to provide
a secure fit (sock like) for
multiple sized wires and lugs.
Wire Caps Instead of Tape
Terminal Point Barriers
oTerminal point barriers used
to cover up trip sensitive points
on wiring blocks and provides a
visual indication of the location
of those “trip” points .
oBefore the task begins, cover
any “trip” point that would
result in an unwanted event if
inadvertently touched or
bridged.
Terminal Point Barriers
P = Positive DC Voltage
T = Trip Point
“P” wire
“T” wire
“T” wire
“P” wire
Without Terminal Point Barriers
With Terminal Point Barriers
Plastic Sheeting as Barrier
o Flame retardant plastic used to build a
physical barrier to prevent incidental
contact with “live” electrical control
components (use when pulling control
cable, stripping wire, etc)
o The plastic is held in place with nylon
blanket clamps.
Events vs. Decline in Experience and Increase In Workload
The Expectation/Requirement
o
Technicians and Electricians work together to identify the task risks during
pre-job briefing and task preview.
o
Once risks are identified, use the work zone identification kit tools to build
appropriate barriers and defenses to prevent unwanted equipment operation.
Contact: [email protected]
804-257-4738