Art. 682 and Lake Fountains??

[jahilliard]

We install the services and Control panels for decorative lake fountains all the time...I'm sure we have done 100 or more and will do another 50 in the next few months. Of all that we have done only 2 have been turned down because they didn't comply with Art. 682...specifically section 682.11 "Service Equipment shall disconnect when the water level reaches the height of the established electrical datum plane." I'm curious has anyone else experienced this scenario and I am also curious as to how you were able to comply with the requirement. We did come up with a solution but it seemed rather ridiculous and it was a home made installation that most likely wasn't able to meet any type of UL listing. For the most part I'm frustrated because meeting this requirement just doesn't seem practical seeing as how in every case we have our service installed adjacent to a transformer sitting on the ground servicing several bldgs or homes and if the water level were to reach a dangerous level there would be much more dangerous scenarios than our little service. Our electrical is for a decorative fountain...it doesn't control the water level in any way. I could understand if it were intended to be a safety limit type thing but this isn't the case. Just looking for some feedback on the Article and maybe a creative solution to meeting the requirement. Thanks

 

[mgookin]

Can you tell me what the code means by "the established electrical datum plane"?

My experience is with Base Flood Elevation and I've gone around with GC's and EC's for decades on it.

Are the two the same?

 

[jahilliard]

the Article itself defines it in several different ways. Basically it's 2 ft above the established water level based on the specific application. ??

 

[mgookin]

As to transformers sitting on grade, around here POCO transformers are submersible.

As to that datum plain, I found a definition as you describe.

As to what others do to comply, I found where one had come up with a float switch that triggers a contactor. But don't take that from me to be the best way to accomplish the objective. Let's see how or if others chime in here; there are many very smart and very experienced people on this site...

 

[cpinetree]

We have done similar, float switch to trip shunt trip main breaker. It ain't pretty but it has passed inspection on multiple jobs. We use a standard lift station float hanging down and straped off to the pedestal. When the float is lifted it sends 120v to shunt trip breaker and kills power to the rest of the circuits.
We also try to keep the panel on the pedestal above the plane so as not to have to run wire back to the sub feed point.

Now if you need to kill power back at the main panel (I am assuming this is fed from another point aka sub panel / main panel) then you get to run additional wire all the way back to that point so you can trip the shunt tripped feed breaker.

Our application is often floating docks and or very low docks fed from shore panels, so this may or may not help your application.

 

[jahilliard]

We have come up with a way to install a float switch but it wasn't pretty. We also normally don't install a panel, just a fused disconnect that feeds the Control panel with all the GFCI protection etc. So where would we need to disconnect the power to meet the requirement? can it be done at the control panel or would it have to be ahead of that? and if so is there a way to do it with a disconnect seeing as how it's already in place.
Also...the pad mount transformers are "submersible"? I had no idea.

 

[jahilliard]

Where are you getting your float switch from? I think that may be a simple good idea.

 

[cpinetree]

Where are you getting your float switch from? I think that may be a simple good idea.

Pump suppliers have them, as well as the big box stores - have to cut the ends off the big box store units.

 

[cpinetree]

We have come up with a way to install a float switch but it wasn't pretty. We also normally don't install a panel, just a fused disconnect that feeds the Control panel with all the GFCI protection etc. So where would we need to disconnect the power to meet the requirement? can it be done at the control panel or would it have to be ahead of that? and if so is there a way to do it with a disconnect seeing as how it's already in place.
Also...the pad mount transformers are "submersible"? I had no idea.

The power disconnection point really depends on if your control panel is high enough above the datum plane if so you could use a shunt tripped main in it. If not we use a 2 circ panel with a shunt trip breaker ahead of the panel and run the shunt wires along with the feed wires.

 

[mgookin]

...
Also...the pad mount transformers are "submersible"? I had no idea.

I'm not saying they all are, but I was out on a Temp CO inspection for a big box retailer (orange) and the first thing I saw driving up was that a stormwater retention pond had been built around an area that had a pad mount POCO xfrmr. My first thought was first rain = no power, or worse. I had the EC get POCO out there and POCO told me it is submersible; POCO even opened it up and showed me all connections were indeed waterproof. FYI: It's not sitting at the bottom of the pond today; they elevated it later on.

Also, POCO is not subject to NEC. There is no valid argument that you're at the same elevation as their pad mount transformers.