5.3. ERMUSR 04-17-2008~/j
Elk River .~.
Municipal Utilities
13069 Orono Parkway • P.O. Box 430
Elk River, MN 55330-0430
April 2, 2008
To: Elk River Municipal Utilities Commission
Jerry Takle
John Dietz
Jerry Gumphrey
From: Bryan Adams
Subject: ARC Flash Assessment
Phone: 763.441.2020
Fax: 763.441.8099
At our March 12, 2008 Elk River Municipal Utilities Commission meeting we discussed the
ARC Flash Assessment. Attached is my memo dated March 4, 2008 for your reference.
Your staff has completed the ARC Flash Assessment and Clothing Requirements which is
attached for your approval. This change will also necessitate a clothing policy change.
Section 31 Employee clothing in our Employee Handbook is proposed to change as follows:
(Underlined is added, line thru is deleted)
31. EMPLOYEE CLOTHING
The Utilities will, after an initial issue of five fire retardant long sleeved shirts and €rve sl3e~-t
~''°°~~°~' ~'~~~*~, five fire retardant pants and five fire retardant tee shirts per outside employee
exposed to electric hazards, replace annually. As an option, one fire retardant hooded fleece m
be substituted for 2 fire retardant long sleeved shirts and sweatshirt maybe substituted for long
sleeve shirt with a maximum of 2. The Utilities will also replace as needed: ~`Z:~T~ fire
retardant lined and unlined bib overalls,'°~= fire retardant lined parka and hood, laiame~
1;I4z4 fire retardant lined bomber jacket, and hats with the appropriate emblems and identification.
The policy also includes the following additional items: lineman's climbing boots, summer work
boots er--sliees, rubber boots, rubber overshoes, insulated winter boots, and coveralls (used for
maintenance on trucks). It is expected that the employee wear these work items during working
hours. Worn out items to be turned in. The Utilities will issue a check to the supplier for the
covered items. For outside operational employees whose job duties do not require Nemex fire
retardant clothing, ~^~ '~-~~ non-fire retardant clothing items will be furnished. Short sleeve
shirts will be provided instead of pang.
'-~+J~
Elk River -~=
Municipal Utilities
13069 Orono Parkway • P.O. Box 430
Elk River, MN 55330-0430
March 4, 2008
To: Elk River Municipal Utilities Commission
Jerry Takle
Jerry Gumphrey
John Dietz
From: Bryan Adams
Subject: Arc Flash Assessment
Phone: 763.441.2020
Fax: 763.441.8099
The arc. f.7ash issue has raised its head again. Approhimately 20 years ago arc flash became a
discussion point with the adoption of OSHA 1910.269.. Arc flash. is the light and heat energy
given off in an unintentional electrical contact between two energized conductors or an energized
conductor and ground. This is analogous to the light and heat energy given off as in arc welding
only much more interise due to the higher voltage involved. This is not electrical burns from
contact to an energized conductor where the current flows through the body.
OSHA 1910269 states that the clothes worn by linepersons cannot make the injuries wur~:e from
arc flash. At this point, linepersons could only wear clothes of natural fabrics such as cotton,
silk, wool, etc.; not synthetic materials like rayon, nylon, etc. that can melt and cause further
injury from burning fabric.
Section 410 of the National Electric Safety Code (NESC) requires employers to do an arc flash
assessment by January f, 2009. The employer shall require employees to wear clothing or a
clothing system that has an effective arc rating not less than the anticipated level of arc energy.
The NESC has an exception which states that for secondary systems below 1 OOOv, applicable:
work rules required by this part and engineering controls shall be utilized to limit exposure. In
other words, we are not required to follow the arc flash assessments below 1000v. Unfortunately
this is the area where many hazards are. The National Electric Code (NEC) which generally
applies to voltages less than 600v (covers electricians, not electric utilities) and the National Fire
Frotection Agency (NFPA) do not include the NESC exception. The NFPA does not apply to
electric utilities.
The level of energy from an arc flash is a function of distance from the arc flash, clearing time of
fault (how quickly the fuse or disconnection device reacts and opens the circuit) and magnitude
of fault current available. These three variables make a detailed engineering analysis very
difficult and only generalized conclusions can be made.
The dilemma we have is there are three codes (NESC, NEC, and NFPA) that do not agree, yet
the code we fall under excludes the area that contains the real hazards, an imperfect engineering
analysis with only general conclusion. The end result is that we may have to change our work
practices and the protective clothing we provide to our employees.
Attached please find the following information for your review:
1) Arc flash analysis completed by USG.
2) Copy of our current Fire Retardant Clothing Policy.
3) Section 31 of our Employee Handbook titled Employee Clothing. The clothing we now
provide satisfies Hazard Risk Category 1 per the arc flash analysis.
Staff is currently reviewing our Fire Retardant Clothing Policy and work rules and will make a
recommendation at our meeting.
ELK RIVER MUNICIPAL UTILITIES
FIRE RETARDANT CLOTHING POLICY
Attached to this policy are the ARC/Flash Assessment, Requirements for Personal
Protective Equipment, and Clothing Flammability Assessment Table for electrical work.
Vvhen working on or near energized equipment the operational personnel of the Eik River
Municipal Utilities shall wear clothing [underwear, outerwear (pants, shirt) weatherwear
jacket, coveralls, etc.)] not containing acetate, nylon, polyester or rayon. The outer layer shall
be a minimum of 14 oz. 100% cotton pants or coveralls and a minimum of 7.5 oz. 100%
cotton shirt, jacket or coat. Under the following circumstances a nomex or equal fire retardant
switching coat shall be worn as the outer layer.
i) In Substations while operating Line or By-pass fuses, disconnect blades, air switches or
any live line work on 15 Kv and above.
2) Performing live line work on the secondary side of any 3 phase transformer bank. (/f
only taking line voltage readings; cotton clothes with rubber gloves are
adequate).
3) Removing/ Installing direct 3 phase metering on energized meter banks greater than
270 volts.
If clothing becomes ripped, frayed, etc. it shall be replaced. In regard to clothing
appearance to our customers, no cut-off shirts, muscle shirts, or white safety shoes shall be
worn.
~~\~~~
~~.~°,~~.R.,U
Elk River Municipal Utilities
Arc Flash Assessment and Clothing Requirements
When working on or near energized equipment, operational personnel of the Elk River
Municipal Utilities shall wear clothing having a minimum rating of 8 calories. Employees shall
wear natural fiber (cotton, wool) undergarments. Eight calorie clothing system shall include
long sleeve FR shirt, FR pants, safety eyewear, leather safety boots, and appropriate rubber
gloves and sleeves, face shield optional. The following working condition shall apply:
I) Working in Substations
a) While operating electrical equipment and 8 ft. or more from ~~ner~~ir~~1 cyuipment, 8
calorie clothing shall be worn (face shield is optional).
b) While operating electrical equipment less than 8 ft.~`from energized equipment, 8
calorie clothing, face shield and FR coat shall be worn.
c) A minimum of cotton FR tee shirt clothing in substations shall he worn for the
following tasks.
1. Changing setting on feeder re-closure car~troller (nun reclose, hot line tag, ground
trip block etc.)
2. Changing or verifying settings on L`I~C or (,~)It~" hr~aker.
3. Meter reading.
2) Working general overhead lines, ~ calorie clothing Shall be worn (face shield optional).
3) Working underground primarywhen moving elbows, fusing, phase testing, 8 calorie
clothing with face shield shall be worn.
4) Working underground 3 phase secondary.
a) Secondary testi~i~~ and placing locating clamp, 8 calorie clothing with face shield shall
be worn.
b) M~~•~~in~~ ~~i~ ~~u~~ erciaaiity testing in transformers, employees shall work in a 2 person
crew. I3u~h cn~~~loyees shall wear 8 calorie clothing with a fire retardant coat, face
shield az~c~ appropriate rubber gloves and sleeves.
5) ~Metcr change out =leather gloves shall be worn. When changing out an energized
meter, the employee shall use a meter puller or wear an arc flash face shield.
6) For single phase residential meter change out, the 8 calorie clothes system is not required.
Undergarments and outerwear shall be of natural fibers. Leather gloves shall be worn.
When changing out an energized meter, the employee shall use a meter puller or wear an
arc flash face shield.
If clothing becomes ripped, frayed, etc. it shall be replaced. In regard to clothing appearance to
our customers, no cut-off shirts, muscle shirts, or white safety shoes shall be worn.