Capacitorx
Member
- Location
- Dover,de
scenario,at work the mechanical contractor ran the heat trace lines for boiler and chiller lines on roof and made all the splices.well the mechanical contractor has now subbed the completion of this job to us,one word nightmare, anyway heres the specifics.4, heat trace lines ran on a roof each about 500 ft long with no branches but theres 1 to 2 splices in each line and of coarse the end caps.its rated at 5 watts per foot 32 A max.so first thing was to megger test each one and so i did.most of the circuits were reading about 2k megs between inner conductor to outer braid all except one which for both inners to braid was under 1 meg so i looked into that circuit and found that the end cap was not installed properly they never striped the outer conductor or cut out the braid so strands were making some contact between outer braid and inner conductor .i found 2 lines were done like this well actually the one didnt even have a end cap put on at all.but the real problem is on every line between inner to inner i was getting about only 5 to 10 ohms on each one which puzzed me basicly it seemed to be dead shorted on every line inner to inner.we did the math and came up with thirty ohms at 2500 watts with the amperage at about 9.but i wasnt sure because i thought it would only be thirty with voltage applied.when i fixed the 2 that had end cap problems both those lines went to 1000 ohms each.which i thot was way high but better than a dead short unless there are bad splices in both of those lines.but the other 2 lines still remain at 5 to 10 ohms even after i checked their end caps but there are splices in all of these line and they are buried under the insulation the mech contractor never labeled the outer jacket of the insulation to signify where the splices are.can anyone help me with this its giving me a giant headache?oh the maker of the ht is raychem.
