Fault on underfloor heating mat.

[dtec dave]

Hi All

I have a fault on an underfloor heating mat which is as follows

L-N no continuity (should be around 200 ohms)
N-E short circuit
L-E clear

I need to find the exact location of the fault so I can take a tile up to repair it, I have thought about hiring a thermal imaging camera, just wondering if anyone has any other ideas?

Cheers

 

[Deleted account]

R u doing insulation resistance or continuity

What are your actual reads?

 

[telectrix]

it's a non-metallic needle ina haystack.there are specialist companies with the gear to find this, but is it worth the effort? personally, i'd rather buy a pair of socks.

 

[Midwest]

Do you shaawerr with your socks on, cheapskate

 

[telectrix]

Do you shaawerr with your socks on, cheapskate

i don't shower, up here we are civilised and have indoor baths,

 

[Midwest]

i don't shower, up here we are civilised and have indoor baths,

Is that the metal bath, hanging on the outdoor privy. Do you set it up in front of the living room fire? Who goes last.

 

[telectrix]

Is that the metal bath, hanging on the outdoor privy. Do you set it up in front of the living room fire? Who goes last.

kitchen fire, mate, kitchen fire. bonding cable no reach living room.

 

[Midwest]

kitchen fire, mate, kitchen fire. bonding cable no reach living room.

You 'following' me

 

[AJshep]

How do you find the fault with a thermal imaging camera?
10mins of constant IR testing at 1000v to warm the dead short up or is there a specialist bit of equipment you can use ?

 

[Charlie_]

Best thing you can do is try to trace it with a tone generator and tracer

 

[DPG]

If there's no continuity L to N then it is completely open circuit and will not heat up. So there will be nothing for the thermal image camera to pick up.

 

[AJshep]

If there's no continuity L to N then it is completely open circuit and will not heat up. So there will be nothing for the thermal image camera to pick up.

I meant apply a voltage (IR) To N-E.

 

[DPG]

I meant apply a voltage (IR) To N-E.

Sorry, was replying to the OP.

 

[freddo]

L-N no continuity (should be around 200 ohms)
N-E short circuit
L-E clear

There is a certain 'less than safe' way to locate the problem area with the fault you have... It involves disconnecting some things, and connecting other things (ideally through an isolation transformer) to a variac, then winding it up while monitoring the current with a clamp meter to ensure the section of element that is connected is not overloaded. When it starts heating the problem area should be locatable with a thermal imaging camera.

Don't ask me how you repair the damaged part though. Just trying to access the element from under the adhesive can cause more damage, especially if the insulation is soft silicone. Far better to replace the entire element, or just do without.

 

[DPG]

Freddo, good idea locating using the N-E short rather than the open circuit. Pretty likely both issues will be at the same location. I should have thought of that.