KMU SUBSTATION WORKSHOP

Rick Aguilar, Director of Job Training & Safety

KMU SUBSTATION WORKSHOP

JUNE 29-30, 2016 OTTAWA, KS

Energized & De-Energized Work Procedures in Substations

KMU Substation WorkshopJune 29-30, 2016

• Hazards & Safety Rules

• Qualified Personnel & Task-Based Hazard Mitigation

• Worksite Applications & Considerations

• Electric Arc Protection

• FACE Reports & Lessons Learned

• Electrical Principles

Ohm’s Law

Circuit review



HAZARDS & SAFETY RULES



• Re-energized line(s)

• Induced voltages & currents

Magnetic induction

Capacitive induction

• Step potential

• Touch potential



• Magnetic voltages

• Capacitive induction



Equal to the difference in voltage, given by the

voltage distribution curve, between two points at

different distances from the electrode



Voltage resulting from

touching a conductive

object that is connected

to a remote energized

component



• OSHA Regulations

1910.269(n)(2)

• General. For any employee to work transmission and distribution

lines or equipment as deenergized, the lines or equipment shall

be deenergized under the provisions of paragraph (m) of this

section and shall ensure proper grounding of the lines or

equipment as specified in paragraphs (n)(3) through (n)(9) of this

section.

1910.269(n)(3)

• Equipotential zone. Temporary protective grounds shall be

placed at such locations and arranged in such a manner that

the employer can demonstrate will prevent each employee

from being exposed to hazardous differences in electric

potential.



• Standards

IEEE Std. 1048-2003

NESC C2-2012

• Placement of grounding

sets for employee

protection



• 512 Substations

512.1 General Rules

512.2 Working in an Energized Substation

512.3 Hazardous Energy Control (LOTO)

512.4 Batteries

512.8 Circuit Breaker Maintenance & Repair

512.9 Working in Transformer Tanks & Vessels

512.10 Work in Manholes & Vaults

512.11 Splicing & Terminating

512.12 Vault/Manhole Rescue

*Rev. 15, 2012



• 507 Overhead Lines and Equipment

507.6 Working on De-energized Lines and Equipment

507.11 Stringing or Removing De-energized Conductors

507.12 Stringing Adjacent to Energized Lines

507.13 Grounding – General

507.14 Equal Potential Grounding

• 509 Underground Lines and Equipment

509.5 Work on De-energized Cables

509.7 Grounding – URD Circuits

*Rev. 15, 2012



Nominal voltage to ground

Minimum Clear Distance for Condition 1,2

Condition A Condition B Condition C

m ft m ft m ft

601-2500 V 0.9 3.0 1.2 4.0 1.5 5.0

2501-9000 V 1.2 4.0 1.5 5.0 1.8 6.0

9001 V-25 kV 1.5 5.0 1.8 6.0 2.8 9.0

Over 25-75 kV3 1.8 6.0 2.5 8.0 3.0 10.0

Above 75 kV3 2.5 8.0 3.0 10.0 3.7 12.0

*Table 512.1. Minimum Depth of Clear Working Space

at Electric Equipment, Over 600 V

APPA Safety Manual 15th Ed. pg. 233



Nominal voltage (kV)

Phase-to-Phase

Distance

Phase-to-Ground Phase-to-Phase

m ft m ft

0.050 to 0.300 2 Avoid Contact Avoid Contact

0.301 to 0.750 0.33 1.09 0.33 1.09

0.751 to 5.0 0.63 2.07 0.63 2.07

5.1 to 15.0 0.65 2.14 0.68 2.24

15.1 to 36.0 0.77 2.53 0.89 2.92

36.1 to 46.0 0.84 2.76 0.98 3.22

46.1 to 72.5 1.00 3.29 1.20 3.94

Table R-6

Alternative Minimum Approach Distances for Voltages of 72.5 kV and less 1



Altitude above

sea level (m)

Correction

Factor

0 to 900 1.00

901 to 1,200 1.02

1,201 to 1,500 1.05

1,501 to 1,800 1.08

1,801 to 2,100 1.11

2,101 to 2,400 1.14

2,401 to 2,700 1.17

2,701 to 3,000 1.20

3,001 to 3,600 1.25

3,601 to 4,200 1.30

4,201 to 4,800 1.35

4,801 to 5,400 1.39

5,401 to 6,000 1.44

Table R-5 Altitude

Correction Factor

Multiply distances from

Table R-6 with correction

factor corresponding to

altitude of work



QUALIFIED PERSONNEL & TASK-

BASED HAZARD MITIGATION



• One who has received training in and has

demonstrated skills and knowledge in the construction

and operation of electrical equipment and installation

and the hazards involved.



• One who has the skill and knowledge related

to the construction and operation of the

electrical equipment and installations and has

received safety training to recognize and

avoid the hazards involved.

May be considered qualified with respect to

certain equipment & method but still

unqualified for others.



• Employer must provide the employee in charge with

all available information that relates to the

determination of existing characteristics and conditions under §§1910.269(a)(4) and 1926.950(d):

• Employer shall ensure employee in charge conducts

a job briefing

Information on existing characteristics

Information about existing conditions

§§1910.269(c)(1)(i) & 1926.952(a)(1)



Employer to employee in charge, employee in

charge to coworkers

• Hazards associated with

the job

• Work procedures involved

• Special precautions

• Energy-source controls

• Personal protective equipment requirements

§§1910.269(c)(1)(ii) & 1926.952(a)(2)(b)



Number of briefings

• At least one before

each day or shift

• When there

significant changes

§§1910.269(c)(3) & 1926.952(a)(2)(c)



Short discussion

• Satisfactory if the work involved is routine

Detailed discussion

• If work is particularly hazardous, or

• If employees cannot be expected to recognize and

avoid the hazards involved



• Isolate – not able to

contact energized part

• Insulate – same

principle used with

energized work



• Magnetic voltages

• Capacitive induction



• Key is to place worker in parallel with low resistance path to shunt dangerous current & limit voltage across worker.

• Return path considerations System neutral

Ground rod

• Approved ground clams, jumpers ≥ #2 copper, clean surfaces



ELECTRIC ARC PROTECTION

Subtitle



• Outer layer of clothing must be arc-rated for

incident energy exceeding 2.0 cal/cm2

• Arc-rated protection must cover entire body,

with certain exceptions:

Protection for hands (rubber gloves with protectors

or, for exposures ≤ 14 cal/cm2, heavy-duty (12oz)

leather work gloves)

Protection for feet (heavy work shoes or boots)

Protection for the head under certain conditions

§1910.269(l)(8) & §1926.960(g)



Federal Register pg. 20489

§1910.269(l)(8) & §1926.960(g)



• Head when incident

energy is < 9 cal/cm2

(single phase), or < 5

cal/cm2 for other

exposures

• Hands when wearing

rubber gloves and

protectors

• Feet when wearing

heavy leather boots



Hazard Risk

Category 0Hazard Risk

Category 2

Hazard Risk



Category 1



• 100% cotton long sleeve shirt

• Long pants

• Safety glasses

• Hearing protection

• Leather and insulated gloves (as required)

• Leather work boots



• 4+ cal long sleeve shirt & long pants (or) coveralls

• Hardhat

• Safety glasses

• Arc rated face shield

• Hearing protection (inserts)

• VR gloves

• Leather gloves




• 8+ cal long sleeve shirt & long pants (or) coveralls

• Hardhat

• Safety glasses



• VR gloves

• Leather gloves




• 25+ flashsuit w/ hood over long sleeve shirt and long pants

• Safety glasses



• VR gloves

• Leather gloves




• 40+ flashsuit w/ hood over arc-rated FR long sleeve shirt and long pants

• Safety glasses



• VR gloves

• Leather gloves




• Layering Outer layers must be flame resistant

Under layers must be non-melting

• Fit – Clothing shall fit properly (loose), w/ least interference

• Coverage – Clothing must cover potentially exposed areas (wrist, neck)

• Care & Maintenance Inspect before use

Launder according to mfg’s instructions

*Photo courtesy of Salisbury



• Equipment exposed to electric arcs must

pass drop test post-exposure

• No requirement to pass an arc rating test



• Assess worksite for hazards

• Determine appropriate

controls

• May use isolation,

insulation, and

equipotential zones

• Ensure no contact with

equipment and ground

rod



• Stringing adjacent to

energized lines and equipment

• Placement of tools and

materials

• Worksite access control

• Ensure no contact with

equipment and ground rod



FACE REPORTS & LESSONS

LEARNED









• Inspections and P.M. need to be completed and

are critical safety element for personnel and facilities

• Control access and ensure personnel are qualified

for tasks

• Communicate PPE & MAD requirements with

exposed workers



Rick Aguilar, CUSP, PHR

Director of Job Training & Safety

Kansas Municipal Utilities

101 ½ N. Main

McPherson, KS 67460

(316) 293-6933

[email protected]

Serving municipal utilities for 85 years

mailto:[email protected]

Documents

KMU SUBSTATION WORKSHOP