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20 | nVent.com
nVent.com | 21
Heating Cable Repair
Figure 21: Clean conductors
Note: Do not clean the magnesium oxide
powder from the conductors of the cold lead
section as silver solder is applied only to the face
of the conductor.
With pliers, break away 1/2 in (13 mm) of flux from
end of flux coated brazing rod. This will help prevent
excess flux from contaminating the magnesium
oxide powder. There should be enough flux left on
the brazing rod to allow proper brazing.
Hot-hot joint
: Using oxy-acetylene torch, heat
conductor with a small flame (see Appendix E)
and touch or wipe brazing rod onto the
tip
of the
conductor by turning the rod between the fingers.
This will ensure that the flux melts off the rod and
onto the conductor evenly. Take care not to get
any flux near the end of the cable where it might
contaminate the magnesium oxide powder.
Figure 22: Tin heating cable conductor
Emery
cloth
Brazing rod
Oxy-acetylene
torch
Heating cable