Nace CP 1, Course Manual

Page: 449 / 535

RP0290-2000
NACE International 7
During this initial energizing period, all circuits shall be
tested.
5.3.1.1 Proper circuit polarity shall be verified.
5.3.1.2 The rectifier shall be tested for proper
operation. The accuracy of all rectifier meters
shall be verified with a calibrated portable meter.
5.3.1.3 Proper cathodic protection current
distribution through all anode feed circuits shall be
determined. If panel boards for such testing were
not included in the system design, clamp-on DC
ammeters or other techniques should be used.
5.3.1.4 The anodes shall be inspected for proper
operation. Areas of relatively high initial current
discharge shall be investigated.
5.3.1.5 Reference electrodes and other
monitoring devices shall be tested.
5.3.1.6 Additional equipment required by the
cathodic protection system design shall be
inspected for proper operation.
5.3.2 After completion of the initial energizing
inspection, the impressed current cathodic protection
system should be adjusted for current requirements in
accordance with Section 2.
5.3.3 After adjustment, the cathodic protection system
should be operated continuously for a period of at least
one month before conducting acceptance testing to
verify that the operational criterion selected in Section 2
is being met. Environmental or physical extremes can
affect system performance and must be considered in
acceptance testing.
5.3.4 Tests should be conducted to verify that
electrically isolated metal is not adversely affected by
stray current from the operation of the impressed
current cathodic protection system.
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Section 6: Operation and Maintenance of Impressed Current Cathodic Protection Systems
6.1 This section presents recommended procedures and
practices for maintaining continuously effective and efficient
operation of impressed current cathodic protection systems.
6.1.1 Electrical measurements and inspections are
necessary to determine that, once achieved, protection
according to the selected criterion is maintained and
that each part of the impressed current cathodic
protection system is operating properly. Conditions
that affect protection are subject to change with time.
Corresponding changes may be required in the
cathodic protection system to maintain protection.
Periodic measurements and inspections are necessary
to detect changes in the cathodic protection system.
Conditions in which operating experience indicates that
testing and inspections need to be made more
frequently than recommended herein can exist.
6.1.2 Adequate locations, number, and types of
electrical measurements shall be used to determine the
effectiveness of cathodic protection.
6.2 All cathodic protection systems should be inspected as
part of a preventive maintenance program to minimize in-
service failure. Inspections should include a check for
electrical shorts, ground connections, meter accuracy,
rectifier efficiency, and circuit resistance. Annual surveys
should be conducted to verify that the cathodic protection
system is meeting the protection criterion. The accuracy of
permanent embedded reference electrodes should be
evaluated during these surveys. The effectiveness of
continuity bonds and isolation of cathodic protection circuits
should be evaluated during the periodic surveys. These
surveys should be conducted under the direction of persons
described in Section 1 of this standard.
6.3 All sources of impressed current should be checked at
intervals of one month or at such intervals as necessary to
ensure effective operation of the system. Evidence of
proper functioning can be normal current and voltage
output, a signal indicating normal operation, or a satisfactory
polarized potential state of the embedded steel.
6.4 The test equipment used for obtaining cathodic
protection data should be of an appropriate type.
Instruments and related equipment should be maintained in
good operating condition and checked periodically for
accuracy. A list of appropriate test equipment is provided in
Appendix C.
6.5 Remedial measures should be taken where annual
surveys and inspections indicate that protection is no longer
effective. These measures may include the following:
6.5.1 Repair, replace, or adjust components of the
cathodic protection system.
6.5.2 Provide supplementary cathodic protection
where additional protection is necessary.
6.5.3 Repair, replace, or adjust continuity bonds and
defective isolating devices.
6.6 An operations and maintenance manual that includes
the following information should be provided.