3
Heating Cable Repair
42 | nVent.com
nVent.com | 43
Check the insulation resistance (IR) again. A value
greater than 20 MΩ should be attained. If the IR
is lower, remove the moisture from the cable by
following the drying out procedure in Appendix D.
Repeat IR test.
Figure 61: Check insulation resistance
Using oxy-acetylene torch with a large flame, apply
heat to the end cap sweeping the flame from
bottom to top of end cap 4 to 5 times. This will aid
in removing any moisture trapped in the powder.
Heat the top of the plug and apply flux around area
where the plug will be brazed to the end cap using
flux coated brazing rod. Ensure that the flux is applied
around the entire junction and braze the plug to the
end cap.
Do not apply excess heat at this time, as excess
heat will cause the air within the end cap to expand
and cause a pinhole in the silver solder. If a pinhole
does develop, the surface should be cleaned and
filed before attempting to re-solder the end cap.
Large flame
Figure 62: Braze plug to end cap