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Raychem-IM-H58033-XLTracePipeFreezeProtectionCOM-EN 18/01
7
Test Procedures
A
B
A
B
A
B
Braid
Figure 29: heating cable resistance measurement test
The approximate location of the fault, expressed as a
percentage of the heating cable length from the front
end, is:
Fault location: D =
A
x 100
________
(A + B)
example:
A = 1.2 ohms
B = 1.8 ohms
Fault location: D = 1.2 / (1.2 + 1.8) x 100
= 40%
To locate a low resistance ground fault, measure
between bus and braid.
A
B
A
B
A
B
Braid
Figure 30: low resistance ground-fault test
The approximate location of the fault, expressed as a
percentage of the heating cable length from the front
end, is:
Fault location: D =
A
x 100
________
(A + B)
example:
A = 1.2 ohms
B = 1.8 ohms
Fault location: D = 1.2 / (1.2 + 1.8) x 100
= 40%
The fault is located 40% into the circuit as measured
from the front end.
