Hot Work Permit For Troubleshooting Machines ( Routine Troubleshooting ) ???

[Davebones]

We have a machine shop with quite a bit of CNC's and other type milling machines . We have some maintenance techs that work on these machines on a regular basis . Was asked about them having to have a " Electrical Hot Work Permit " made out each time they work on a machine . They are on these machines almost every day . Was wondering how other places deal with a " Routine Permit " for this type of troubleshooting and repair work ? How long time period would a permit cover ?

 

[petersonra]

I have been in places where they have to get one every time.

I have also been in places where one is issued annually to each electrician that covers everything in the plant for a year.

And just about everything in between.

 

[RichB]

I have been in places where they have to get one every time.

I have also been in places where one is issued annually to each electrician that covers everything in the plant for a year.

And just about everything in between.

Ditto--seems everyplace is different--have worked in places that didn't require anything--just left it to the tech to decide

 

[gadfly56]

FWIW, places I've usually been at a hot work permit is good for one shift, unless specified otherwise. As others have said, it's site specific so YMMV. The thing you want to do is achieve whatever level of safety is being pursued without making the procedure so onerous that people are highly motivated to violate it in the interest of trying to "git 'er done". Then no one wins.

 

[wbdvt]

NFPA 70E-2015 contains a definition for testing. It is in Article 100, under Working On (energized electrical conductors or circuit parts). Diagnostic (testing) is taking readings or measurements of electrical equipment with approved test equipment that does not require making any physical change to the equipment.

Article 130.2(B)(3) lists exceptions to a Work Permit. Troubleshooting is one of those exemptions.

Of course, your electrical safety program can always exceed the standards.

One thing will comment on is that an arc flash hazard may still be present in the cabinets and unless there is no potential for an arc flash, then proper PPE is required. For example, I have seen machine cabinets that have 480V coming in to a breaker and then 480V is fed off to a motor contactor, then to motor as well as to a control voltage transformer. Also in that cabinet can be control relays or in more modern ones PLCs. Typically the PLCs may be worked on by Process Control Technicians who are may or may not be Qualified Electrical Workers and may not be in proper PPE.

 

[kwired]

NFPA 70E-2015 contains a definition for testing. It is in Article 100, under Working On (energized electrical conductors or circuit parts). Diagnostic (testing) is taking readings or measurements of electrical equipment with approved test equipment that does not require making any physical change to the equipment.

Article 130.2(B)(3) lists exceptions to a Work Permit. Troubleshooting is one of those exemptions.

Of course, your electrical safety program can always exceed the standards.

One thing will comment on is that an arc flash hazard may still be present in the cabinets and unless there is no potential for an arc flash, then proper PPE is required. For example, I have seen machine cabinets that have 480V coming in to a breaker and then 480V is fed off to a motor contactor, then to motor as well as to a control voltage transformer. Also in that cabinet can be control relays or in more modern ones PLCs. Typically the PLCs may be worked on by Process Control Technicians who are may or may not be Qualified Electrical Workers and may not be in proper PPE.

I would like to think it is generally accepted that the 480 volt motor circuit as well as higher power level capable control circuits needs to be in separate enclosure or isolated section so that when working on the PLC you are not subjected to those hazards, and is a reason you see more 24V control systems on a lot of equipment with PLC's or other advanced controllers then you once did.

 

[Jraef]

I just had this conversation with a military equipment contractor with a large facilities group, they shared their 28 PAGE ELECTRICAL HOT WORK PERMIT document with me! It requires 6 levels of management approval and typically takes a week to obtain... They are basically hog tied. The basis of this conversation was their desire to replace old switchgear and MCCs with new Arc Resistant versions. When I explained to them that while it does change the PPE requirements for closed-door tasks, nothing changes once the door is open. They will still have to shut down, or suit up and get the permit signed. The looks on their faces was sad to witness, they had been misled by someone else as to the value of AR labeled equipment. It's still valuable, but does NOT allow that process to take place in the way it was promoted by the salesman.

So let that be a lesson by the way. Regardless of what salesmen sometimes say, Arc Resistant labeled equipment (and it must be LABELED by the way) can indeed make a difference in the PPE required for simple tasks performed while the doors are all closed, such as turning breakers or disconnects on or off. AR labeled equipment means HRC 0 if using the tables, as opposed to whatever it might be otherwise based on the incident energy and calculated cal/cm². But once you crack open a door, that no longer counts for anything. It's bunny suit time!

 

[gadfly56]

I just had this conversation with a military equipment contractor with a large facilities group, they shared their 28 PAGE ELECTRICAL HOT WORK PERMIT document with me! It requires 6 levels of management approval and typically takes a week to obtain... They are basically hog tied. The basis of this conversation was their desire to replace old switchgear and MCCs with new Arc Resistant versions. When I explained to them that while it does change the PPE requirements for closed-door tasks, nothing changes once the door is open. They will still have to shut down, or suit up and get the permit signed. The looks on their faces was sad to witness, they had been misled by someone else as to the value of AR labeled equipment. It's still valuable, but does NOT allow that process to take place in the way it was promoted by the salesman.

So let that be a lesson by the way. Regardless of what salesmen sometimes say, Arc Resistant labeled equipment (and it must be LABELED by the way) can indeed make a difference in the PPE required for simple tasks performed while the doors are all closed, such as turning breakers or disconnects on or off. AR labeled equipment means HRC 0 if using the tables, as opposed to whatever it might be otherwise based on the incident energy and calculated cal/cm². But once you crack open a door, that no longer counts for anything. It's bunny suit time!

That pretty much falls into the category of "onerous".

 

[petersonra]

I spent something like 6 or 9 months in an explosives plant once working on some equipment.

They had a version of a hot work permit that was required almost to walk onto the production floor. No battery powered anything was allowed unless it was IS unless one had a hot work permit. That included things like computers, watches, beepers, cell phones, etc.

You could get a hot work permit that was good for a whole week for troubleshooting purposes.

Only the plant manager could sign. No on else was designated. If he was not there you had to fax it to him so he could sign it and fax it back.

 

[sparks0304]

jouryman electrician

jouryman electrician

we work with a hot work document, any time doors are open it's arc flash ppe, no exceptions

 

[big john]

we work with a hot work document, any time doors are open it's arc flash ppe, no exceptions

I get suspicious every time I read about "no exceptions" requirements.

Are you guys at least basing your PPE on actual incident energy calculations, or did some goof in an office somewhere just decide that any time a door gets opened somebody needs to be wearing the bomb suit?

 

[jim dungar]

I get suspicious every time I read about "no exceptions" requirements.

:thumbsup:

Incident energy values are only part of the story.
NFPA70E requires a risk analysis as part of the PPE selection process.

 

[kwired]

:thumbsup:

Incident energy values are only part of the story.
NFPA70E requires a risk analysis as part of the PPE selection process.

And I'm sure there are some cases where the "bomb suit" doesn't provide enough protection, but you never will know if you don't do proper analysis.

 

[Davebones]

I just saw Proposed Changes to 2015 NFPA 70E . Section 130.2 ( B ) ( 3 ) A energized electrical work permit shall not be required under the following conditions . ( 1 ) TESTING , TROUBLESHOOTING , and VOLTAGE TESTING . I would think this would allow us to work on equipment without a permit along as we use the correct PPE .

 

[jim dungar]

I just saw Proposed Changes to 2015 NFPA 70E . Section 130.2 ( B ) ( 3 ) A energized electrical work permit shall not be required under the following conditions . ( 1 ) TESTING , TROUBLESHOOTING , and VOLTAGE TESTING . I would think this would allow us to work on equipment without a permit along as we use the correct PPE .

This exception has basically been part of NFPA70E since its inception.
Correct PPE and risk assessment are required.