5 Jan 91
0.0052 x p x 1n [D/2 AR x DE)]
rod anode in feet, D is the tank diameter in feet, AR is the
radius of the anode circle in feet, and DE is an equivalent
diameter factor from figure 2-17.
For wire anode circle or hoop (in a water storage tanks):
where RA is the anode-to-electrolyte resistance, p is the
electrolyte resistivity, DR is the diameter of the anode
circle in feet, DA is the diameter of the anode wire in
feet, and H is the depth below the high water level in
Experience has shown that the diameter of the anode wire
circle (D) should be typically between 40 and 70 percent of
the tank diameter.
Wire resistance (RW) is the sum of both the rectifier-to-
anode lead and the rectifier-to-protected-structure lead.
where LW is the length of wire in thousands of feet and
RMFT is the resistance of the wire in ohms per 1000 ft.
The structure-to-electrolyte resistance (RC) is dependent
primarily on the condition of the coating.