Installation Guide

nVent.com/RAYCHEM | 31
9 OPERATION, MAINTENANCE AND
PIPE REPAIRS
Caution: consult the heat tracing system documentation prior to
maintenance/repair/modification.
9.1 Heating cable operation
• Temperature exposure must not exceed that specified in
nVent product literature. Exceeding those limitations will
shorten the service life and may permanently damage the
heating cable.
• Pipe insulation must be complete and dry to maintain the
correct temperature.
9.2 Inspection and maintenance
• Visual inspection: Exposed heating cable and pipe insulation
should be checked periodically to make sure that no physical
damage has occurred.
• Upon completion of maintenance/repair/modification, the
insulation resistance of the heating cable shall be measured
and recorded and shall not be less than 1000 Megaohms
• Meggering: The system should be meggered regularly. When
meggering the insulation resistance from the main supply
panel, it is recommended that the test is performed between
L/N (together) and PE. Freeze protection systems should be
meggered before the winter months each year (see section
8). Temperature maintenance systems should be tested at
least twice a year. Function testing of electrical protection
and temperature control systems should be carried out at
regular intervals.
• The Periodic Inspection Record on the following pages
should be filled out during maintenance of each circuit in
your system.
9.3 Piping systems repair and maintenance
• After maintenance/repair/modification, test the operation of
the earth-fault device of each affected circuit or equivalent.
• Isolate heating cable circuit.
• Protect the heating cable from mechanical or thermal
damage during pipe repair work.
• Check heating cable installation after pipe repairs and
restore thermal insulation following the recommendations
in Section 6. Check correct functioning of electrical
protection systems.