Showing posts with label NEC 680. Show all posts
Showing posts with label NEC 680. Show all posts

Tuesday, July 16, 2013

Swimming Pool Expert Witness Construction & Design

Expert Witness - Swimming Pools, Construction & Design
National Electrical Code - Section 680 Swimming Pools & Spas


The electrician didn't understand why I disapproved of this installation...
There were many things wrong:

  • Indoor rated CAT 5 Cable was installed in underground conduits.  Underground or Direct Burial cables should be used, as they contain a silicone gel to prevent water intrusion.
  • The metal gutters are not specifically designed for swimming pool lighting junction boxes, and were utilized for the underwater lighting.  These non-compliant boxes are not equipped with the required corded strain relief, grounding bar or the internal and external bonding connections.  ONLY fixtures specially designed for this purpose may be utilized for underwater fixtures [NEC 680.24(A)(1), NEC 680.24(D)], IRC4106.8.5, IRC4106.8.1].
  • The metal gutters were not properly supported, protected from damage or waterproof.
  • Bare #8 copper bonding wires do not connect the exterior of the box to the bonding grid [NEC 680.24].
  • A stranded green #8 copper bonding wire is not contained within the PVC conduits from the Pentair Panel terminal bars to the pool light junction box terminal bars [NEC 680.24(F)].
  • Stranded green #8 copper wires are not contained within the PVC conduit between the pool light niche and the gutters.  The #8 copper wire connection inside of the light niche must be encapsulated in an approved potting compound [NEC 680.23(B)] .
  • All grounding and bonding connections in a swimming pool installation MUST connect to a terminal bar or equipment bonding lug – wire nut connections are not permitted on grounding or bonding wires [NEC 680.24(F)].  
      They are just TOO IMPORTANT TO COME LOOSE!
  • Non-pool light circuits may not share pool lighting conduits unless they are GFCI protected [NEC 680.23(F)].
  • Low voltage and high voltage wiring are contained within the same panels, conduits and junction boxes – data wiring inside of conduits with high voltage electrical conductors [NEC 800-52].
His question... "What's your problem?

Oh, only a minor detail of potentially killing people in their swimming pool.

Paolo Benedetti 
Aquatic Artist, Watershape Consultant, Expert Witness 
"Creating water as art."™ 
Aquatic Technology Pool and Spa©
www.aquatictechnology.com

Saturday, January 26, 2013

Expert Swimming Pool and Spa Advice from International Designer

The causes of most construction defects are directly attributed to one of 2 causes - failure to follow instructions, plans or project specifications and/or the lack of qualified supervision.
 
Failure to Follow Instructions

Most defects in construction projects are directly attributed to someone not taking the time to READ instructions.  Whether they be the product usage insert, manufacturer's installation manual or the engineer's plans and notes... failing to take the time to read AND understand the instructions results in errors.

Sometimes these errors can be huge - incorrect strength or diameter of steel, walls that are too thin, pipe diameters that are too small or electrical systems that are incorrect.  These types of errors can result in a project that may be structurally unstable or dangerous to swimmers.

When these instructions refer to another code or standard, it is the installers responsibility to seek out and understand those codes as well.   

In the plans if the structural engineer states, "Shotcrete must be installed in compliance with ACI 506R-05," then the installer must understand what those standards require 

The structural engineer does not need to reprint the entire referenced standard in the plans.  Why?  Because anyone who installs shotcrete as a part of their business should already be aware of, possess a copy of, and be following the requirements of ACI 506.

If the instructions that are enclosed with electrical components are not read and adhered to, a potentially life threatening situation can be created.  The failure to properly bond metallic components can result in a fatal electrical shock.  Though most electrical components clearly state how they are to be installed, many will also refer to NEC 680 & 682.  Again, anyone who builds swimming pools or fountains should have a copy of these codes and be intimately familiar with them.

The Lack of Qualified Supervision

Note the word "qualified?"  Just because a project has on-site supervision does not mean that the supervision is worth anything.  The supervisor may just be directing the progress and may "no nuthin' 'bout da details uf da wurk."  Therein lies the problem... the blind leading the blind.

The person who supervises the work of others, needs to know how that work is to be performed.  The person supervising the design, planning and construction needs to be familiar with:
structural engineering
soils
excavation 
building forms
hydraulics
plumbing 
electrical
reinforcing steel
shotcrete (wet or dry mix methods)  
tile
masonry
plaster
concrete
mechanical (venting)
fuels (approved piping, venting, shut-offs)
automation and controls 

This is not to say that they need to be a licensed expert in each of these fields.  But, it is saying that they need to know enough about each topic to question what others are telling them is right.  Anyone can make a mistake, even experts that the contractor may hire.  

The contractor needs to understand that pools with diving boards must comply with various floor contour and shape requirements, and which diving boards can be safely used in each.  They must ensure that the project design and engineering complies with these codes and minimum dimensional shapes.

The swimming pool contractor needs to be able to recognize differential soils or buried trash during an excavation.  They need to be smart enough to have the structural and soils engineers weigh in on the discovery.  It may mean nothing or it may be a big deal - but they need to let the experts decide which!

The contractor needs to understand the basics of hydraulics and the Virginia Braeme-Baker Safety Act, in order to deliver a swimming pool that is safe from entrapment hazards, unwarranted restrictions, high energy consumption and cavitation.  The need to ensure that the suction point sumps are the correct size, are compatible with the flow rate ratings of the drain covers and if sumps are field fabricated, that they meet the requirements of the VGBSA.

The supervisor on the project needs to know what each of the sub-trades are required to do.  Whether it is the electrician, plumber, mechanical, masonry or concrete sub-contractor - they need to know the codes and standards that apply to each.  And they have a duty to ensure that these codes are followed and complied with - even if the local inspectors do not enforce the codes.

Because when the client has any doubts about the project, an expert will come in and dissect the project.  Each component of the pool that is found non-compliant may be required to be corrected.  Tearing out completed work to repair underlying defects can quickly consume any project profits.

And anyone in construction will agree... it is cheaper to do it right the first time!

Take the time to READ and UNDERSTAND the plans and installation instructions.  

Employ QUALIFIED project supervisors or go get educated... there are some excellent programs on swimming pool construction available.  The $3,000 spent on one of these programs, will save you much more than that, if an expert is ever hired to evaluate one of your projects.


Paolo Benedetti 
Aquatic Artist, Consultant & Construction Defect Expert Witness 
"Creating water as art."™ 
Aquatic Technology Pool and Spa 
©www.aquatictechnology.com