nvent Raychem HAK-C-100 Installation Instructions Manual page 14

TROUBLESHOOTING GUIDE
Symptoms
Power output appears correct but pipe
temperatures are below design value.
Power output is zero or appears low.
Note: The power output is temperature-sensitive and requires a special procedure to determine its value:
1. Check the pipe temperature under the thermal insulation at several locations.
2. Power the heating cable and allow it to stabilize for 10 minutes, then measure current and voltage at the junction box.
3. Calculate the power (watts/ft) of the heating cable by multiplying the current by the voltage and dividing by the actual
circuit length.
Power (watts/ft) =
Probable Causes
Insulation is wet.
Insufficient heating cable was used
on valves, supports, and other heat
sinks.
Thermostat was set incorrectly.
Improper thermal design.
Low or no input voltage.
Circuit is shorter than the design
shows, due to splices or tees not
being connected, or the heating
cable having been severed.
Improper connection causing a
high-resistance connection.
Control thermostat is wired in
normally open position.
Pipe is at an elevated temperature.
Heating cable has been exposed to
excessive moisture or chemicals.
Heating cable has been exposed to
excessive temperatures.
Current (A) x Voltage (Vac)
Length (ft)
Correction
Remove and replace it with dry insulation,
and secure proper weatherproofing.
Splice in additional heating cable but do
not go over maximum circuit length.
Reset thermostat.
Check with the local or factory
representativefordesignconditions;
modify as recommended.
Repair electrical supply lines and
equipment.
Check routing and length of heating cable
(use "as builts"). Connect splices or tees,
locate and replace the damaged heating
cables, then recheck the power.
Recrimp with the correct procedure.
Tighten set screws on terminal block.
Rewire in the normally closed position.
Reduce pipe temperature. Check the pipe
temperature. Verify the power output of
heating cable. See note below for method.
Replace damaged heating cable. Check
the pipe temperature. Verify the power
output of heating cable. See note below for
method.
Same as above.
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