3
Heating Cable Repair
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Use the emery cloth to clean flux from each brazed area
and visually inspect to ensure that there are no pinholes
or gaps which could allow moisture to enter (Figure 42).
Emery
cloth
Figure 42: Clean and inspect brazed areas
If pinholes are found, touch up pinholes as necessary by
cleaning the area and applying more braze. Ensure that
all flux is removed from all brazed areas.
Caution:Joint will be hot. Do not touch joint or
cable with bare hands.
Again, test the insulation resistance with a 1000 V DC
Megohmmeter (Figure 43). Minimum IR should be 20
MΩ. Quench with a rag soaked in water by wrapping it
tightly around the joint (Figure 44). Be careful to not get
water inside the repair sleeve or corrugate. If needed, a
rag can be tied around the MI heating cable at the sleeve
to prevent water from running down the cable. Leave on
for 4 to 5 minutes. If there are any remaining pinholes,
moisture will be absorbed into the joint as it cools and
the reading on the Megohmmeter will drop. Joint must
be cool to get a proper IR reading.