555.5 as applied to floating docks

hardworkingstiff

Senior Member
Location
Wilmington, NC
The 1st sentence of 555.5 says
Transformers and enclosures shall be specifically approved for the intended location.
What does that mean to you?

Does it mean it has to say in the literature that it is designed to go on a floating dock?

Would a NEMA 3R transformer with stainless steel enclosure be "approved for the intended location"?

I've got a call in to the plans reviewer to discuss it, but I was wondering what y'all thought.
 

kwired

Electron manager
Location
NE Nebraska
The 1st sentence of 555.5 says

What does that mean to you?

Does it mean it has to say in the literature that it is designed to go on a floating dock?

Would a NEMA 3R transformer with stainless steel enclosure be "approved for the intended location"?

I've got a call in to the plans reviewer to discuss it, but I was wondering what y'all thought.
Calling AHJ is the right thing to do.

ART 100 definitions:

Approved. Acceptable to the authority having jurisdiction.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I wonder what rational basis the typical electrical inspector would have to make a decision as to what to approve or not approve? It just seems so far outside of their area of expertise.
 

iwire

Moderator
Staff member
Location
Massachusetts
I wonder what rational basis the typical electrical inspector would have to make a decision as to what to approve or not approve? It just seems so far outside of their area of expertise.
If I was an inspector I would feel pretty insulted reading that.


Certainly there are things that go beyond an inspectors areas of expertise but there are far more things that can be decided with just a bit of commonsense and experience.
 

iwire

Moderator
Staff member
Location
Massachusetts
why not just an encapsulated xfmr? what does the 4x get you? that is why I question the wisdom of leaving this kind of thing up to an inspector.
I question the wisdom of you making this call.

A standard encapsulated transformer installed outdoors will rot away leaving the conductors exposed.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I question the wisdom of you making this call.

A standard encapsulated transformer installed outdoors will rot away leaving the conductors exposed.
A 3R encapsulated xfmr as suggested by the OP will outlast most of us. It will probably rust in a humid environment but that is cosmetic.

maybe if it is a marine environment it is different but for just humidity, there is no need for SS.
 

kwired

Electron manager
Location
NE Nebraska
Would they be more giving if your install is above the 100 year flood plain verses mean high tide?
A floating dock is not supposed to be below the water even if the water rises, unless the water rises higher than the dock was designed in some way, but maybe you have more problems to worry about than just the transformer in that scenario. Sometimes a structure away from the normal shore becomes a "floating structure" in those cases.

Don't you have someone phone number at the POCO? Seems that in the end you'll have to
do what they want any ways...
I fail to see why POCO should care if this beyond the service point, or at least beyond metering equipment.

A 3R encapsulated xfmr as suggested by the OP will outlast most of us. It will probably rust in a humid environment but that is cosmetic.

maybe if it is a marine environment it is different but for just humidity, there is no need for SS.
Fresh water and salt water environments will have much different corrosion rates even with everything else being the same.
 

cadpoint

Senior Member
Location
Durham, NC
Hurricanes are at the coast are the 100 years flood, look at Irene pictures,

Here's the path that went right through the Pamlico Sound, now the OP is not exactly
there and below what happen in the Sound. The sound is only average 20' deep. It drained the western side of the outer banks average 3- 5 and then sent the water back in with additional footage! Note how high the piers columns are.

It's not a stretch that the Power company's are concerned with distributing their service.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Maybe where you are, but not around here.

Yes the encapsulation will outlast us all, the painted steel wiring compartment at the bottom will rot away. I have seen it more than once.
And how does this hurt anything? Any painted or galvanished sheet metal in the same area will also rot away eventually. It is not just transformers. Are you planning to require SS for all sheet metal boxes out there? Or just transformers?

I have seen all kinds of sheet metal boxes that rotted away outside nowhere near a dock or pier.

In any case. No inspector has the authority to make that determination unless it has been granted him or her by the actual AHJ. I am not aware of many (if any) AHJ that have given that power to individual inspectors.

The AHJ can certainly make that determination.
 
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kwired

Electron manager
Location
NE Nebraska
And how does this hurt anything? Any painted or galvanished sheet metal in the same area will also rot away eventually. It is not just transformers. Are you planning to require SS for all sheet metal boxes out there? Or just transformers?

I have seen all kinds of sheet metal boxes that rotted away outside nowhere near a dock or pier.

In any case. No inspector has the authority to make that determination unless it has been granted him or her by the actual AHJ. I am not aware of many (if any) AHJ that have given that power to individual inspectors.

The AHJ can certainly make that determination.
The AHJ itself may not necessarily be qualified to make that kind of decision either and that is why they hire people with certain qualifications to be the inspectors. The AHJ may technically be nothing more than a law passed by the people it serves who have no electrical work qualifications or experience. Now a governing body may set some rules for this AHJ, hire an executive director for the department, or something similar, but it still comes down to the AHJ itself may not be an individual person or there is a person in charge that maybe has a fair amount of power in executing the AHJ role but otherwise has little qualifications to make such decisions. One thing that is typically common though is that the smaller the jurisdiction, the more likely it is that there could be unqualified people to make such decisions, as you could have a village or city board of elected officials that are non electrical workers that are effectively the boss that hires a one man inspection department. This could happen in a larger city, but with more professionals being inspected there is a greater chance of someone taking appropriate action to correct any issues in that department.
 
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