Static/Electricity problem with Electrical Underfloor Heating, help needed

[jazzythumper]

Hi there first post, but probably quite a complex problem.


I have built a solid plywood studio/office, all the walls floors and ceilings are made from 2no. layers of 24mm plywood Essentially a plywood tube with glass windows at either end. On top of this is a Flexel EcoFilmset underfloor heating system like this, I installed this myself as per the manufacturers instructions, but it has been connected to the thermostat by an electrician.


Flexel Ecofilm Set Element - 300mm wide 5.0m Length


This was laid on top of the insulation and underneath a 15mm layer of plywood. The protective sheet was not installed (which I think is where the following problem occurred)


When the underfloor heating is turned on or up, static (or electricity) can be felt in the plywood walls (not the floor but the walls) this is where the junction box and the thermostat are located.


Could it be that the metal contacts where there wires are connected between the sheets lie are in contact with the floor and causing the static, however if this was the case surely you’d be able to feel the static in the floor as well as the rest of the studio/office?


All the sockets are fitted with metal back boxes which are rebated into the plywood? Would plastic ones be better to completely isolate the underfloor heating thermostat and cable that are in the wall?


I thought that wood or plywood is an insulator?


Any help on the above would be greatly appreciated.

 

[Bobster]

Are you sure it's static?

 

[jazzythumper]

Are you sure it's static?

I don't know it's a tingling when touching the wall? But no electric shock.

Jazzy

 

[telectrix]

what type of studding is between the ply sheets? if it's metal or with metal screws fixing the ply sheets, you have a potential shock hazard. could be a screw has penetrated a cable. needs a thorough investigation by a qualified electrician equipped with the necessary test instruments to evaluate the cause.

 

[jazzythumper]

what type of studding is between the ply sheets? if it's metal or with metal screws fixing the ply sheets, you have a potential shock hazard. could be a screw has penetrated a cable. needs a thorough investigation by a qualified electrician equipped with the necessary test instruments to evaluate the cause.

No studding, the plywood is 2no. layers of plywood screwed together, the cabling is on the outside.

Jazzy

 

[Darkwood]

What were the testing results of all circuits within the area where you get this issue?
Are your circuits installed to meet the current 17th BS7671 regulations?
Is their an RCD protecting the circuit?
Why wasn't the protective layer fitted ... this could mean the install is a hazard - subject to manufacturers consultation, I assume from the website the missing layer is the vapour barrier and it does say this is required....

Ironic that we spend our lives been told we haven't followed plans etc by the Architects and here we have an Architect DIYing in Electrics and not following the instructions tut tut ... I feel a sense of Karma is afoot.

 

[jazzythumper]

What were the testing results of all circuits within the area where you get this issue?
Are your circuits installed to meet the current 17th BS7671 regulations?
Is their an RCD protecting the circuit?
Why wasn't the protective layer fitted ... this could mean the install is a hazard - subject to manufacturers consultation, I assume from the website the missing layer is the vapour barrier and it does say this is required....

Ironic that we spend our lives been told we haven't followed plans etc by the Architects and here we have an Architect DIYing in Electrics and not following the instructions tut tut ... I feel a sense of Karma is afoot.

Yes it was the Vapour Barrier that was not installed (i won't go into why), for various reasons. Could this mean that any of the metal connectors between the film are in contact with the floor? But then why is the floor not conducting any electricity?

Thanks

Jazzy

 

[Darkwood]

The issue could be non related fault elsewhere that is tracking back into any earthed system or natural moisture in the wood.... I would isolate any suspect circuits and get someone in to test the install... static electric is a very short sharp shock and usually can be heard ...if you are getting a continuous tingle then you are potentially at very great risk of injury or death...

Can you answer the questions I put to you ?

Wiring and connecting any circuit up requires strict test procedures to ensure safety and knowledge of regulations is also needed.. now in your job you may pick up certain requirements and get over-confident to what you believe you can do as DIY but you seem to have missed vital safety steps as well as ignored manufacturers instructions ... again the tingling your getting may be unrelated but as a matter of urgency I would isolate circuits that are suspect and ensure if this is at home that family members keep away from the area.. Get a competent Electrician in ASAP to test all local circuits to the issue.

 

[Marvo]

But then why is the floor not conducting any electricity?

When you get a 'tingle' it means you're in contact with two points that are at different potentials. With only a small potential difference it's quite possible you'll only feel the tingle at one of the points of contact and usually at the point with less contact area. The surface area of the soles of your feet is very large compared to the surface area of your finger.

From an electrical point of view if there's enough leakage current to cause a tingle then the fault should be visible with an IR tester or even a leakage clamp meter so an electrician should be able to measure the fault and advise on a remedy.