[davemcq]

The water pipes in my crawl space are wrapped with self-regulating heat tape (& insulation.) i removed a couple runs and froze them in a bucket of water to test and they do work. I am trying to verify that the installed runs are working. I do not currently own a megohmmeter /megger or a hand-held cable fault locator. I’ve tried using a current tester (“beeper”). I know this is not the correct tool but i want to get an opinion of what I am observing. The current tester is indicating current on the full length of some of the runs. A couple of runs it is showing current only up to a certain point. But the strangest is a run that shows current, then seems to have a dead spot, then indicates current further down the line. Is there any “most likely” explanations? Without getting the correct tool, it seems i am flying half-blind. Thank you.
Dave

 

[surferdude2]

There are two types that I know of, the ones that are pre-cut to length with a line cord attached and the kind you can cut to any length and add your own feed and cap off the end to insulate it safe. They both work the same way, they depend upon the resistance built into the web between the line conductors. The pre-cut ones can be had with thermostats built in.

I'd say if the dead spot isn't very long, they are good to go. Be careful not to wrap them over themselves (overlapping) since it will overheat them and they might short out.

I used the 240 volt Rachem brand most times (6watts per foot)... kept a roll in the truck. Cut to fit, nice stuff since the drain lines in the freezers I installed were all different lengths. The 120 vac ones would likely be the same wattage so you can ohms law it out based on length and get a pretty good resistance estimate. That won't do you much good if you don't have an ohmmeter! Get a $10 multimeter from one of the big box stores and you'll have all you need for checking those tapes out and other stuff later.