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Heating Cable Repair
44 | nVent.com
nVent.com | 45
Note: While brazing, it is important to avoid
using excess heat on the portion to be brazed.
Direct flame contact can oxidize the metal surface,
preventing the silver solder from adhering to the
metal. Care must also be taken not to overheat
the end cap, which can cause the conductor joint
(junction) to melt.
Magnesim oxide
powder
Plug
Figure 63: Cross-section of completed end cap
Test the insulation resistance with a 500 volt
Megohmmeter. Minimum IR should be 20 MΩ. Clean
end cap to remove all flux. With Megohmmeter still
connected, quench with a rag soaked in water by
wrapping it tightly around the joint. Leave on for 4
to 5 minutes. If there are any remaining pinholes,
moisture will be absorbed into the end cap as it
cools and the reading on the Megohmmeter will
drop.
Figure 64: Check insulation resistance