renosteinke
Senior Member
- Location
- NE Arkansas
I can't access all my resources - I'm too busy, in Arkansas, making tornados to export to my Southern neighbors - but pause to think about it for a moment.
Here you have a fine wire mesh, wrapped in rubber. During installation, it will be walked on. There might be sharp rubble on the floor. The edges of trowels can get razor sharp with use. Tiles themselves have some pretty good edges, and all the weight of the tile behind them when they fall. I see plenty of opportunity for the insulation to get damaged.
Now ... how will you inspect for damage? All a continuity tester (or ohm meter) will tell you is if the wire is at least somewhat complete from one end to the other. You can remove ALL the insulation, and the meter won't see the difference.
A megger, on the other hand, can best be described as a tool that 'fills a wire with pressurised electricity' ... and then lets you know if even a little bit is leaking out. With something like a heat mat, you don't test between the hot and the neutral - they're supposed to be connected - you test between each of them and the ground. There better not be any electricity getting into that ground . If there is no ground wire, you test between each lead and the mat itself. All the electricity is supposed to stay in the wires.
Now ... do you want to do this only at the start of the job? At the end? Or, at each step along the way? I'd say it's in your interest to stop work as soon as a fault develops. I really like the 'alarm' fulthrotl described. because no one is likely to volunteer to pay to replace the floor, or trash the production schedule.
Here you have a fine wire mesh, wrapped in rubber. During installation, it will be walked on. There might be sharp rubble on the floor. The edges of trowels can get razor sharp with use. Tiles themselves have some pretty good edges, and all the weight of the tile behind them when they fall. I see plenty of opportunity for the insulation to get damaged.
Now ... how will you inspect for damage? All a continuity tester (or ohm meter) will tell you is if the wire is at least somewhat complete from one end to the other. You can remove ALL the insulation, and the meter won't see the difference.
A megger, on the other hand, can best be described as a tool that 'fills a wire with pressurised electricity' ... and then lets you know if even a little bit is leaking out. With something like a heat mat, you don't test between the hot and the neutral - they're supposed to be connected - you test between each of them and the ground. There better not be any electricity getting into that ground . If there is no ground wire, you test between each lead and the mat itself. All the electricity is supposed to stay in the wires.
Now ... do you want to do this only at the start of the job? At the end? Or, at each step along the way? I'd say it's in your interest to stop work as soon as a fault develops. I really like the 'alarm' fulthrotl described. because no one is likely to volunteer to pay to replace the floor, or trash the production schedule.