Connection between anode header cable and each anode
Connection between cable and anode (usually factory made)
Necessary bonds and test wires
The need for additional connections and splices should be carefully evaluated.
The location of all necessary splices and connections should be specifically
shown on the design drawings. The need for additional splices and connections
should be determined by the designer of the system and not be left to the
discretion of the installer.
Test Stations. There are six basic types of test stations used in
impressed current cathodic protection systems: the potential test station, the
soil contact test station, the line current (IR Drop) test station, the
insulating joint test station, the casing insulation test station, and the
bond test station. The wiring for each of these test stations is shown in
Figures 54 through 59. Test wires should be solid copper, No. 10 AWG, either
TW or RHW-USE insulated. If future bonding across flanges or between
structures may be required, 7-strand copper cables, No. 4 AWG or larger if
required, should be connected to the structure(s) and brought into a test
station for future use.
Test stations may either be located flush with the surface of
pavement or soil as shown in Figure 54 or in an above grade test station as
shown in Figure 57, manufactured specifically for this purpose. Flush-mounted
test stations are preferred in paved areas or other areas where damage by
vehicles, etc., is anticipated. Above grade test stations are preferable in
unpaved areas. In addition to test stations, balancing resistors are
sometimes required when multiple anode beds are used with a single rectifier.
These resistors should be installed in an above grade terminal box as shown in
Figure 60. The location and wiring of all test stations should be included in
the system design. All test wires should be color coded, and marked with
noncorroding metal or plastic identification tags indicating what they are
Bonds. Bonds between sections of the protected structure or
between the protected structure and a foreign structure should use 7-strand
copper cable, No. 4 AWG or larger insulated cable. All resistive bonds should
be brought into a test station for adjustment. Direct bonds may also be
brought into test stations if future adjustments or connections may be
required. All bond-to-structure connections should be made using thermo-weld
connections, insulated by epoxy encapsulation. Standard details for bonding
are shown in Figures 61 through 68.
Insulating Joints. Insulating joints between sections of a
structure are often installed in order to break (electrically) the structure
into sections that can be protected by independent cathodic protection
systems, or to separate sections that require cathodic protection from those
that do not. These joints can either be directly buried, be located in valve
pits, or be located above grade. If they are directly buried, they should be
furnished with a test station as described in para. 6.7.3, and shown in
Figures 69 through 72.