The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
230 or 345 kV transmission lines?
by Vlado
Today at 09:33 AM
breaker meltdown
by crselectric
Today at 12:42 AM
Electrical mast flashing product
by ThomasWinfrey
09/22/16 12:14 AM
What estimating software do you recommend?
by sparky
09/21/16 07:20 PM
"Dry Run" Inspection goes awry
by HotLine1
09/20/16 07:39 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 17
sparky 9
gfretwell 9
sparky66wv 8
Vlado 6
Who's Online
0 registered (), 262 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#213184 - 03/27/14 10:09 PM 70E quandry
TheGreatSparkalini Offline
New Member

Registered: 08/08/05
Posts: 4
Loc: Sanford, Maine USA
I need to know if my training is lacking or if a concern from a manager has no merit. The manager is insisting that 30 cal flash gear is needed to reset a tripped 3000A 480 VAC main breaker. The breaker and all the gear around it is fully enclosed. The Approach is 26.5 ft and limited is 3.6 feet. Am I wrong to assume that these barriers only apply with the covers open. I definitely will need to review 70E to set myself or the manager straight. I appreciate his zeal to keep us safe but this seems extreme. What do you all think?

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#213187 - 03/28/14 11:01 AM Re: 70E quandry [Re: TheGreatSparkalini]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
If the covers are all on, no PPE is required, much less a 30 cal suit.

Ask the manager if he puts on flash gear to reset one of his breakers at home

rolleyes

Top
#213188 - 03/28/14 11:42 AM Re: 70E quandry [Re: TheGreatSparkalini]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6785
Loc: Brick, NJ USA
Is there any concerns over what tripped the 3000 amp main?

Hopefully it was the GF
_________________________
John

Top
#213192 - 03/28/14 02:10 PM Re: 70E quandry [Re: TheGreatSparkalini]
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
Originally Posted By: TheGreatSparkalini
Am I wrong to assume that these barriers only apply with the covers open.


Appropriate PPE is always required, regardless of covers being present or absent.

closed covers mitigate any possible shock incident, and they probably do help in the prevention of an AF occurrence, but the do nothing to lower the amount of incident energy.

While I might judge the 'normal operation' of a 3000A breaker between open and closed as having a low risk of an AF occurring, there is no way I would 'reset' a tripped breaker without PPE based on the available incident energy.

Top
#213193 - 03/28/14 02:13 PM Re: 70E quandry [Re: electure]
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
Originally Posted By: electure
If the covers are all on, no PPE is required, much less a 30 cal suit.


The PPE requirements need to be part of the company's Electrical Safe Work Practice program.

Top
#213195 - 03/28/14 02:22 PM Re: 70E quandry [Re: JBD]
LarryC Offline
Member

Registered: 07/05/04
Posts: 775
Loc: Winchester, NH, US
Quote:
The PPE requirements need to be part of the company's Electrical Safe Work Practice program.


So the outside consultant with a vested interest in separating you from your money, will specify the most conservative interpretation of the 70E rules in order to validate their cost to the company. Meanwhile you will need PPE to plug in a vacuum cleaner in the office spaces.

Top
#213196 - 03/28/14 04:48 PM Re: 70E quandry [Re: TheGreatSparkalini]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
Bob,
Refer the manager to Table 130.7(C)(15)(a) of 70E,
available @
http://www.depts.ttu.edu/opmanual/OP60.14B.pdf

It lists the Hazard/Risk Category Classifications.

Panelboards or Switchboards Rated >240 V and up to 600 V (with molded case or insulated case breakers)

CB or fused switch operation with covers on

Hazard Risk = 0
______________________________________________________

600 V Class Switchgear (with power circuit breakers or fused switches)

CB or fused switch operation with covers on

Hazard Risk = 0





Top
#213202 - 03/29/14 11:29 AM Re: 70E quandry [Re: LarryC]
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
Originally Posted By: LarryC
So the outside consultant with a vested interest in separating you from your money, will specify the most conservative interpretation of the 70E rules in order to validate their cost to the company. Meanwhile you will need PPE to plug in a vacuum cleaner in the office spaces.


If the people doing your analysis are the same ones that are selling you your PPE, you probably have a point.

My point is; it is not a requirement of NFPA70E that you employ any more PPE than is necessary to perform the task.

The typical AF study says how bad things could be (the hazard), not how likely they are to occur(the risk).

70E clearly says that the risk must be analyzed as well as the danger. The is partly why their 'task tables' result in a Hazard Risk Category instead of simply cal/cm^2.

Top
#213203 - 03/29/14 11:33 AM Re: 70E quandry [Re: electure]
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
Originally Posted By: electure
Bob,
Refer the manager to Table 130.7(C)(15)(a) of 70E....


And make sure that all of the conditions (fault current, opening times, and regular maintenance) are met.

Top
#213208 - 03/29/14 12:48 PM Re: 70E quandry [Re: TheGreatSparkalini]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
This is like most things "safety" related. If it is worth doing, it is worth over doing.

You only have to look ad lead paint and asbestos abatement this in action. Someone dug up some sewer pipe here in a road expansion project that *might* have had some asbestos in it and instead of some reasonable response, they shut down the project for months, hauled about 100 yards of dirt for "safe disposal" and treated the pipe like it was plutonium. Everyone involved was punished in some way and the contractor went bankrupt. An overpass took years and many extra millions to complete.
_________________________
Greg Fretwell

Top
Page 1 of 2 1 2 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals